Fertility Management at Roxbury Farm - Small Farm Central Control

© Jean-Paul Courtens 2010

Fertility Management at Roxbury Farm

A Personal Narrative

Introduction

page 3

Chapter 1 Physical Properties page 4

characteristics of good vegetable land page 4

Chapter 2 Soil Structure and Tillage page 5

characteristics of stable structure page 5

strategies to support stable structure page 5

purpose of tillage page 6

planting system for vegetables page 7

Chapter 3 Biological Fertility page 9

introduction page 9

compost

page 10

compost process at Roxbury Farm page 10

compost to offset losses in crop production page 11

Cover and Green Manure crops page 12

advantages of cover and green manure page 12

disadvantages of cover and green manure page 14

what we seed what month page 14

Compost or green manure/ a cost analysis page 15

Crop Rotation page 15

introduction page 15

crop plant families page 16

plant families in rotation page 17

record keeping of rotations in MS Excel page 18

sample crop rotations page 21

disease problems and efficacy of crop rotation page 22

insect problems and efficacy of crop rotation page 24

Biodynamic Preparations page 26

compost preparations page 26

chamomile page 27

dandelion page 27

yarrow page 28

nettle page 28

oakbark page 29

valerian page 29

The field sprays page 30

hornmanure page 30

hornsilica page 31


Chapter 4 Soil Chemistry page 32

Cosmic and terrestrial nutrition page 32

Different schools of thinking on plant nutrients page 33

Application and removal of plant nutrients page 34

Assessment of fertilizer needs page 35

Cation Exchange Capacity (CEC) page 36

Soil pH

page 36

Plant Minerals page 38

Nitrogen page 39

Phosphorus page 39

Potassium page 40

Silica page 40

Calcium page 40

OMRI sources of plant minerals page 41

different compositions of manure types page 42

The correct balance of wood, orchards, bushes, and meadows – with their natural growth of fungi

– is so essential to good farming that your farm will really be more successful even if this means a

slight reduction in your tillable acreage. There is no true economy in using so much of your land

that all the things I have mentioned disappear. The resulting loss in quality will far outweigh the

advantage of the other things. Without this kind of insight into the interconnections and

interactions of nature, it is really almost impossible to engage in an enterprise like farming which

is so closely bound up with nature.”

Rudolf Steiner June 15, 1924


Introduction

Our perspective on soil is modified as soil scientists expand their insight uncovering its secrets.

We are constantly provided with new tools that allow us to improve our management practices. This document will never be static as we do not have the pretense that the following should be seen as an ideal system of management but rather a description and explanation of our present practices.

Soil scientists assess soil quality from three perspectives; the physical, chemical, and biological

characteristics. The physical characteristics though can be described from two very distinct perspectives. One part can be called the phenotype, the part we can improve through management practices, while the other can be called the genotype, the soil as we find it and the characteristics it has in how it was geologically formed. In some ways structural fertility is the result of good management of the physical, biological, and chemical components that make up our soil. In this document we distinguish four different qualities to assess the fertility of a parcel with regards to the best possible use. Important Footnote: The newest version of building better soils for better crops by Magdoff and van Es offers the best foundation to gain a thorough understanding in the many aspects involving soil health (The above graph is an interpretation taken out of that book). Some relatively older books like "Bemesting en Meststoffen" by Ir Rinsema, and "Green Manuring" by Adriaan Pieters (neither one of them are still in print) and Lievegoed "Planetary Forces and Life Processes" served as important sources of information for this manual. The "Agriculture Course" by Rudolf Steiner is an important source of inspiration for the particular farming methods at Roxbury Farm. This manual is written from the perspective of the author based on the unique conditions and his practical experience at Roxbury Farm in Kinderhook, NY.

Soil

Chemistry

Physical

Properties

Biological

components

Soil Health

Soil Structure

http://www.sare.org/publications/soils.htm


1. Physical Properties

There are about 350 acres under Roxbury‟s management.

What crop is growing on it is a direct result of the soil type we are working with. The presence of large rocks, steep slopes, or poor drainage makes some of this land unsuitable for vegetable crop production.

Good vegetable land has: -High carrying capacity (carry the weight of equipment without creating irreversible compaction) -Good natural or artificial drainage -Good access to irrigation water -Deep A horizon (topsoil) that is free from stones -Almost flat with slopes that do not exceed 2%. -Located in a long season micro climate -Good exposure to sunlight -Good air drainage to avoid late spring frosts. -Good access to farm roads -High CEC

At Roxbury Farm of the 120 Acres that are suitable for vegetable crop production, only 45 are

planted in cash crops while another 45 acres are planted in soil improvement crops with the remaining 30 in tall fescue and orchard-grass combined with ladino and red clover for hay. Almost all of the vegetable land is rated category I or II (Occum, Unadilla, Knickerbocker, and Hoosick). The material ranges from coarse sand to a fine silt loam. The remainder of the land at Roxbury is divided between hayfields, pastures, woods, or wetlands. Those places are important in providing feed for our livestock and biodiversity to complement the land committed to cash crops.

When we assess the physical quality of our soils, we determine its physical strength and

limitations. Working land can be like working a horse. First, we need to understand what horse we are dealing with. Is it a workhorse or a riding horse? Each has different qualities. We will not try to pull a heavy load with a riding horse for a prolonged period of time. Within this analogy, our sandy soils are like riding horses. The usefulness of a riding horse is in its speed; while it might pull a plow, it lacks the persistence of a workhorse to complete the task. Sandy soils are great in the early spring since they drain well and warm up quickly. This allows us to work these fields earlier than others. But in the summer, they easily dry out, and can only achieve good yields with irrigation. Our sandy soils do not hold nutrients well and the lack of clay and low percent of organic matter is confirmed in the relatively low cation exchange capacity (CEC). A heavier soil, like a silt loam resembles a workhorse; it works harder at an initially slower pace but with much greater resilience. Silt loam soils warm up a little later in the spring but their ability to hold nutrients and water gives them a great advantage during the summer months.

It has proven more difficult to build organic matter on a sandier soil with large granular particles

compared to the soils that contain smaller particles or some clay. Nutrients tend to drain out of a coarser soil and leaching of nitrogen and other mineral fertilizer can be a problem. The buildup of organic matter and nutrients are like the muscles and fat on a horse‟s body. At times when lots of work is demanded it has the reserves to complete its task. Starting off with a good soil is the best investment a vegetable grower can make. Altering the state of the soil besides drainage and rock picking is hardly ever cost effective compared to the cost of prime farmland. Building organic matter and increasing structure do not alter the state of the soil as they merely improve what is already there.

Some of the bottomland, seen from the Van Buren field


Air

Water

Mineral

OM

2. Soil Structure and Tillage

Structural fertility is reflected in the way soil-particles are connected and organized in relation to

each other. We evaluate how the soil particles are spaced and how many and how large the spaces are in between them. The use of tillage tools and the compaction of tractors can cause the soil aggregates to fall apart as it disrupts the subtle balances that exists in a virgin soil. When aggregates separate into their original components of sand, silt, clay, and organic matter, soils tend to collapse and erode when exposed to the elements. Soils with stable aggregates hold up better when exposed to heavy rain, tillage, wind, etc. Some soils have better physical characteristics to create stable aggregates than others. The Soil Health Team at Cornell University has created a soil test which measures bulk density, water stable aggregates, and other parameters so farmers can evaluate how their practices create or destroy soil structure.

A stable structure will have:

An equal distribution between mineral particles and pores.

Good ability for roots to penetrate.

Good ability to hold water.

Good ability to drain excessive water.

Rye pulled up after spading; soil is held together and the clumps are smooth and round

Soils in hay fields (where manure is applied), in pastures or in cover

cropped land are able to maintain a good structure. The decaying roots, the applied manure, or worked in green plant matter support many microorganisms that jump start the food chain which results in increased soil activity. With the grasses providing a source of carbonaceous materials and the legumes the necessary nitrogen, together they provide the building blocks for the microorganisms in the soil. This increased activity connects the soil particles into aggregates. As the broken down organic matter acts like glue between the particles; the extensive root system of the grasses holds the soil together. Decaying roots and increased soil activity creates pores, which provide for drainage and capillary action in times of drought. Vegetables with their poor root development and need to expose the land tend to degrade the soil structure rapidly creating a need for artificial structure by means of mechanization. Strategies to support good structure are:

Add organic materials with high humus conversion rates (containing fiber and lignin) to increase organic matter.

Add green plant matter or raw manure which increases the water stable aggregates.

Add calcium as building block for clay soils to improve its structure.

Avoid breaking up the soil beyond natural breaking points.

Increase permeation by root systems with crops like sweet clover, chicory, rye with vetch etc.

Increase root activity by using biodynamic preparation 500.

Using frost as an action to fracture compacted soil.

To help determine how we treat the soil during the season, the tillage tool should not fracture the

soil more than when a clump of soil is dropped from a height of three feet. It is ideal to use tillage equipment that has an action similar to that of a hand-fork. A hand fork fractures the soil at the


soil‟s own breaking points. A spade damages the aggregates where it slices the soil. The coloration at the back of the spade (which acts like a plow) is an indication of smeared soil particles. The aggregates that allow the soil to stay cohesive have come apart. Five different purposes of tillage:

Fracturing hardpans with a sub-soiler; depth one or two inches below hard or plow-pan.

Aeration of the soil; Depth anywhere between 8 and 12 inches (top-soil only).

Incorporation of organic material; How deep do you want to put your organic material?

Creating a seed or plant-bed; How smooth and level, and free of plant debris depends on the crop to be grown and the type of seeders and row cultivation tools we have.

Weed Control

Conventional equipment rarely combines all tasks. Only a tractor with a front mounted subsoiler

and a rear mounted spading plow with secondary attachment will accomplish the first four tasks, when a relatively rough seedbed is sufficient.

To establish the depth of the hardpan we use a

penetrono or tensionometer. This is a rod attached to a pressure gauge that reads the resistance the soil gives when the rod is forced in the soil. We found a hardpan at about 12 inches which is deeper than the plowing depth. Plowing is not the only cause of hardpans and this compaction was most likely caused by the use of heavy equipment. n the right: To break this hard pan we use a Yeoman plow which is set just two inches below the hardpan. Sinking it deeper than this is a waste of diesel as the force needed to penetrate any deeper might cause additional compaction. In subsequent seasons we might choose to sink our sub-soiler even deeper until all the disturbing layers are broken. It is important to follow a sub-soiler with a crop like yellow blossom sweet clover that completes the mechanical action of a sub-soiler.

For primary tillage, a Coulter Chisel plow or an

Imants rotary spading plow is used to aerate the soil. In order to incorporate cover crops the use of a rotary mower (which needs to have more than one set of blades to avoid windrowing) or flail-mower is necessary. The chisel plow does not turn the soil and leaves a lot of plant residue on the surface (which btw should never referred to as trash). Afterwards, the land is left quite rough so subsequent passes of a disc harrow followed by a S-tine cultivator harrow are used to smooth out the field. This last tool consists of a combination of several “S” tines, a leveling bar, and a set of

Coulter chisel plow with S tine attachment incorporating potato vines

Yeomanplow breaking up hardpan in sod after first cutting of hay

The shank of a Yeoman Sub Soiler.


crumbling rollers. It leaves the soil level and smooth to plant cover-crops, certain cole crops, potatoes, and squash. Alternatively, the spading plow is able to incorporate (as the picture above demonstrates) a thick stand of sweet clover in one pass. A great disadvantage of the spading plow is its speed (up to 2½ hrs compared to 20 minutes per acre for a coulter chisel plow). For precise placement of small seeds and optimum weed control we need a very level seedbed. To obtain this we use a bed shaper.

For crops that have small seeds and that

require extremely level ground with no clumps or stones on the surface a Bed Shaper is used both after the use of the spading plow or the Perfecta II cultivator. This tool leaves a trench every 72 inches, creating a soil surface that resembles raised beds.

The planting surface of the bed is 54

inches wide and allows for: One row of squash, tomatoes, melons,

cucumber with 72 inches between each row

Two rows of potatoes, corn, cauliflower, broccoli, cabbage, kale, rutabaga, fennel, celery, green beans with 36 inches between each row

Three rows of lettuce, beets, onions, carrots, basil, parsley, mei-ching-choi, broccoli rabe, turnips, celeriac, with 18 inches between each row

Five rows of baby carrots, radishes, with 9 inches between each row Nine rows of salad mix, arugula, spinach, cilantro, dill with 4½ inches between each row

72 inches

row 1 row 2 row 3 row 4 row 5 row 6 row 7 row 8 row 9

The trenches prevent the roots from suffocating during periods of heavy rain. The crops keep

their "feet" dry, as the water flows off the top of the bed into the trenches. The combination of better drainage and the level plant bed prevents some bottom rot but its real value is by creating correct conditions for successful mechanical weed control and to avoid compaction with future passes. the top of the bed is never driven on after primary cultivation.

The chart below shows the number of passes needed in each system:

Cover Crop with small seeded legume Vegetables

Sub-Soiler 1x Sub-Soiler 1x

Coulter Chisel Plow 1x Spader 1x

Disc Harrow 1-2 x

Culti-Mulcher 1x Bed Former 1x

Grain Drill 1x Seeder or Transplanter 1x

Culti-Mulcher (to roll) 1x Row Cultivation Equipment 2-3 x

18”

Rotary spading plow with power harrow working in sweet clover

Bed shaper (modified Buckeye) leaving a smooth and level surface for seedbed


To avoid future compaction:

Avoid at all circumstances to work the soil when it is too wet. Form a ball out of the soil to be worked; it is safe to work soil when it crumbles after release. If the ball remains intact you will risk compaction and smearing of the soil with tillage equipment.

Lowering tire pressure in tires to possibly 6-10 psi for field preparation (on our main field tractor we keep the rear tires at 12 psi and the fronts at 20 psi to avoid excessive wear)

Use wide radial tires and 4 WD for field preparation

Ballast your tractor so wheel slippage is around 10-15% when pulling tillage tools.

Use light tractors with narrow tires in controlled field traffic (trenches of raised bed are the traffic lanes) for transplanting, spraying and weed control

Weed Control Cultural Practices:

Reduce tillage

Alternate cereal/legumes with vegetables in crop rotation

Allow for bare fallow between cover crops and vegetables

Precede summer bare fallow for summer vegetables and spring bare fallow for spring planted vegetables

Cultivate when weeds are in the white germ stage; once you can see them you missed the best opportunity for complete eradication

Prepare seedbed only to the depth of seed placement (¼ to a full inch only) when a stale seedbed is required (carrots leafy greens etc)

Cultivate weeds with equipment that does not bring up new weed seeds

Remove weeds before they go to seed to avoid building up seed bank

Weed Control Tools used at Roxbury Farm:

Lely Tine Weeder in potatoes and snap beans

Basket Weeder for very first cultivation in carrots, beets, lettuce and other fine seeded crops

Bezzerides Spring Hoe as first cultivation in most transplanted crops (except for lettuce) like sweet corn, cole crops, and large seeded crops like snap beans and peas.

Rear mounted Side Knives to complement spring hoes or basket weeder

Rear mounted parallel suspended S tines to complement Spring Hoes for more aggressive cultivation.

Lilliston Cultivator for aggressive hilling in potatoes, cole crops and sweet corn

Hillside Cultivator for aggressive cultivation in plasti-culture

Unverferth Perfecta II Combination Seedbed maker for bare fallow cultivation

Unverferth Perfecta II Bedder for stale seedbed For more info see crop manuals.

Bezzerides Spring Hoes cultivating Brussels Sprouts 5 row Buddingh Basket weeder set up for stale seedbed


3. Biological components

Here we recognize three areas of importance:

-The cycles in nature, that includes decay and decomposition of organic matter. -The creation and maintenance of soils. -The nutritional value of cultivated plants.

According to Elaine Ingham when virgin prairie land, the archetype for a healthy soil ecosystem

is plowed, no pesticides or fertilizers are needed for the first 5 to 15 years. I have no direct experience with virgin land but we all recognize that disease-suppressive bacteria, fungi, protozoa, and nematodes can protect plants from infection, while the natural nutrient cycling and nitrogen retention provides the crops with their nutritional needs. By exposing the soil to the elements, we diminish the number of beneficial organisms and burn up the organic matter. When no new organic matter is returned, we not only stop feeding the beneficial organisms we slowly deteriorate the characteristics of the soil. This process is not any different from overgrazing pasture land. Overgrazing reduces diversity and population of grasses and clovers in our pastures just as working the land reduces the microbial population of the soil. A reduction of these organisms eventually results in disease problems. The challenge of organic farming is to maintain a balance between what is taken from the land and what is returned to the soil without shortcuts like the use of artificial fertilizer or pesticides that cause even greater reduction of soil organism. According to Elaine, one teaspoon of healthy soil should contain about 600 million bacteria, three miles of mycelia, 10,000 protozoa and 20 to 30 beneficial nematodes.

Recognizing the processes that happen in the soil can help make a contribution maintaining a

healthy ecosystem. Nutrients removed from the field have to be returned to close the cycle. This type of nurturing is not unlike any other type of husbandry. We need to distinguish the nutritional requirements of the different creatures that live below the surface of the soil. This process is similar to putting cows on lush pasture. A good farmer feeds all its animals even the ones that can only be seen with a microscope.

Spreading compost has a different effect on soil life and soil quality compared to spreading raw

manure or plowing under green manure. Compost is a finished product with little available carbon left as a food source for microorganism. We make a distinction between the raw and stable components of the organic matter in the soil. Raw organic matter like plowed down green manure or animal manure provide the microorganism with many readily available nutrients. This increased microbial life protects those nutrients from leaching into the groundwater as they become part of their cell structure. Soil building crops and raw manure have showed to increase the water stable aggregates in the soil as their properties act like glue between the soil particles

organic matter in tons/acre

68

Cropland

Total Organic Matter

64

60

10

54

50

56

SodCropland

Time in Years

5 10 15 20 25 5

Based on bemesting and meststoffen by ir W. T. Rinsema et al


Ultimately a healthy soil transforms this raw organic matter into humus, which is the most stable

form of organic matter:

Humus has the ability to absorb both nutrients and water. Its negative charge gives it the ability

to absorb positively charged nutrients like K, Mg, Ca, etc. Compared to clay, which has the ability to hold nutrients and water, humus can hold up to four time more. The nutrients absorbed by humus are available to plants but cannot be washed out by excessive rainfall. Humus also increases the structure of the soil as it becomes part of a water stable soil aggregate.

At Roxbury Farm we maintain a healthy soil ecosystem by applying compost, the cultivation of

soil building crops, the application of broad rotations, and the use of the biodynamic preparations. The following four sections will describe in detail the importance of each component.

A. Compost: Compost as a finished product provides little means of carbonic nutrition for the microorganism

while it does increase the soil‟s long-lasting organic matter. Compost is an important source of nutrients so it should be treated as a fertilizer input that also builds soil. Good compost can introduce new beneficial organisms which could help suppress plant disease. Roxbury Farm presently purchases compost from a local source that uses a mix of cow manure, horse bedding, and woodchips. Good compost should ideally have a C/N ratio of 10/1, and should be free of pathogens and weed seeds, while excellent compost adds a disease suppressing component.

The process of making compost at a Roxbury Farm:

During the winter, the animals are kept in a free-stall setup (we use a greenhouse which allows

for a dry, well lit and relatively warm environment during the winter). In this method, the hay is fed in the form of round bales and placed inside a feeder on top of the packed manure. The animals are kept clean by applying bedding on a regular basis. This can consist of old hay, straw, and/or wood chips. As an unheated greenhouse is subject to collapse during heavy snowfall we added support braces to the trusses (see picture) creating the outline of the feed isle. The sows are kept in separate stalls and all animals have outside access which guarantees their health and well being. Sheep continue to graze all through the winter provided a light snowpack.

After six months, the packed materials can be about a foot deep. In May, the manure is removed

with a skid steer or mini excavator. The pile is built with a manure spreader, with its final shape created by a compost turner. The biodynamic preparations are inserted into the pile by pushing a long stick two feet into the pile. Only small amounts are needed in each hole to ensure the beneficial activity.

The structure provides shelter for 50 ewes (and their lambs in the

spring) and 2 sows (and their litter in the spring)

Greenhouse converted to barn space with feeding isle in the middle


A variety of materials in a

manure-pile allow it to be mostly self-sufficient in the process of transformation. A diverse mix of materials develops a combination of aerobic and semi-anaerobic bacteria. The piles heat up 120° to 160° F. and stay at that point for quite a few weeks. A specially designed cover is placed over the piles to shed of any excessive rain and to keep the moisture in the pile. The cover functions like a skin. It protects the pile from the elements without choking it. A pile has

characteristics like any other animal on the farm: it breathes, consists mostly of water, and has body warmth, so daily observation is needed. When the piles dry out water needs to be added; when the piles heat up beyond 160 F˚ we need to stamp it down as excessive heat will burn up the pile leading to excessive losses, while when it is too cold, we need to turn it to re-activate it. Completely “finished” compost deprives the microorganisms in the soil of nutritional carbon, so the whole process of composting takes only about 6 to 12 weeks. The compost, when applied is not “finished”, but will have lost most of its odor. The most important objective of transforming raw manure into compost is to kill pathogens like E-coli and to "cook" the weed seeds. The ideal time of application is on a cloudy day with plenty of rain in the forecast. After application, the ground is chiseled or spaded. Manure handling can be the weakest link in the farm‟s fertility cycle. At a biodynamic farm, it is important to keep nutrient and OM losses as low as possible. AMOUNTS OF ORGANIC MATTER OF DIFFERENT CROPS REMAINING AFTER HARVEST IN SAME YEAR AND FOLLOWING.

All numbers in lbs. /acre Based on bemesting and meststoffen by ir W. T. Rinsema et al

Crop Underground Above ground Total Remains after one year

Rye 1100 3300 4400 1350

Oats 1250 3300 4550 1400

Potatoes 450 3150 3600 750

Beets 450 300 750 250

Cabbage 900 3600 4500 1000

Peas 350 1400 1750 400

Beans 350 1400 1750 400

Onions 270 180 450 130

Grass-clover

1 year 2250 1350 3600 1050

2 years 6000 1350 7350 2300

3 years 9500 1350 10850 3600

Alfalfa

1 year 1800 900 2700 700

2years 2700 1350 4050 1200

3years 4500 1350 5850 1850

Compost 10 ton 3270 3000

Compotex© covers to help retain nutrients and

moisture in compost pile and to protect

groundwater against pollution.


As the chart above shows vegetables do not retain organic matter in the soil. Besides their poor

ability to fix carbon they also cause greater breakdown of organic matter due to cultivation. Open and cultivated land burns up about 2% of its organic matter each season. Living organic matter burns up at much higher rates than to called dead Organic matter. This breakdown allows our cash crops to thrive as minerals including nitrogen are released out of the OM to the crops. To offset the losses we apply compost. As compost brings in more minerals than our cash crops remove (especially phosphorus) we need to maintain the OM levels with cover crops or sod. If the total weight of an acre of soil is 2,000,000 lbs, and its OM fraction is 3%, the total weight of the OM fraction is equal to 60,000 lbs. 2% loss on 60,000 lbs of OM is equal to 1200 lbs per year. The graph on page 8 shows how quickly organic matter is lost, and how long it takes a sod to build it back up. The chart above also shows that rotations that do not include imported compost need to complement the plowing under of full stands of green manure crops to maintain organic matter levels.

Fibers play an important role in the composting

process. Most fibers are “used up” at the end of the composting process. Hay and straw are good examples of being good energy providers for the microorganism. Their presence is vital in the process, but it is important to include materials that contain lignin. They take a longer time to break down, and this kind of carbon compound is not readily available as an energy source for the

microorganisms. But at the end of the composting process, they contribute to the formation of humus at a much higher rate than fibers do.

All carbonaceous materials have a different conversion rate in becoming humus. Materials with

high lignin fractions like peat moss, woodchips, and leaves have a high humification co-efficient factor. This means that a high portion of the original carbon will eventually become humus. Materials with easily digestible carbon like hay, straw, and manure have a much lower factor. The latter group is an essential component of compost as it contributes nitrogen and other building blocks that are used by the microorganism to grow and multiply. Over time the wood chips and leaves (very low in nitrogen) will break down at albeit a much slower rate.

The eventual goal in applying good compost to the land is to increase the overall health of the

soil. Compost is an effective remedy when our goal is to increase the organic matter level of our soils. Disadvantages are the steady increase of minerals in the soil which can create unmanageable weed problems. High applications of compost on organic vegetable farms have caused many persistent problems with weeds like chickweed, galinsoga, and purslane and possible leaching of phosphorus into the ground or surface water. Therefore it is wiser to maintain soil organic matter through a combination of compost and cover crops.

B. Cover and or green manure crops: Why we use Cover and or Green Manure Crops: Reduction of nutrient leaching

Soluble nutrients are easily washed out over the winter months unless they are taken up by a cover crop.

Reduction of soil erosion A crop of rye seeded in September and plowed under in April is able to keep the soil from eroding away over the winter months. Rye and hairy vetch as a mix are very effective, as they will add to soil-life and increase the mineralizable nitrogen fraction. Although if plowed

a 14 foot mower is utilized to clip the green manure crops


early, the humification co-efficient can be low, soil life is greatly benefited by the mere fact that the ground has not been left exposed. The roots of the cover crops after breakdown form the very important capillaries for drainage as well as water uptake.

Increase of pores in soils and breaking up hard pans

Sweet clover is known for its deep penetration of the soil and breaking of hard pans. But any established grass will greatly increase the amount of pores in the soil. Presence of oxygen promotes breakdown of dead organic matter as it increases microbial activity.

Increase in soil life activity Soil particles are held together by soil life activity esp. by the group of mycorrhizae. The cover crop roots provide the needed sugars and amino acids for the activity of the mycorrhizae. Mycorrhizae provide the plants with better uptake of minerals esp. phosphorus, and allow the plant to absorb water more efficiently by enlarging the root hairs. Seventy-five percent of seed bearing plants have a symbiotic relationship with mycorrhizae unless they are destroyed by the use of mineral fertilizer. Deriving fertility and esp. nitrogen from the use of cover-crops in reaction with nitrogen fixing bacteria allow for a beneficial environment for mycorrhizae. A good example is our heavy reliance on both bell beans and oats to provide the necessary fertility for demanding crops like cauliflower. The beneficial environment created by the growth and eventual breakdown of the bell beans allows for more efficient nutrient uptake by the cauliflower.

Increase in Organic matter content through carbon intake Grasses are known for their excellent ability to fix carbon out of the air. For greatest uptake of carbon in one season, Japanese millet and sorghum-Sudan are favorites. To avoid reduction of nitrogen content due to breakdown mix these crops with forage soybean (not to be confused with regular soybeans)

Fixation of Nitrogen by legumes Nitrogen fixing bacteria, which exist in symbiosis with the roots of the legumes fix nitrogen out of the air and form ammonia. Look at the roots of the legume to find out if nitrogen is being fixed: if the roots have nodules that are red or pink colored inside, it has active bacteria. If the roots do not show nodules, find out if the soil pH is too low or if the particular bacterium is in your soil. Many legumes live in symbiosis with different bacteria. Rhizobium japonicum lives in symbiosis with soy beans, Rhizobium trifolii with clover, Rhizobium meliloti with alfalfa. These crops are usually inoculated with the bacteria before planting. Azobacter species are free living bacteria capable of fixing nitrogen. Efficient legume crops are bell beans, field peas, hairy vetch, sweet, red and ladino clover, and forage soybeans.

Weed management Many crops are able to choke out other weeds. By using short season cover crops we reduce the number of weeds going to seed. This results in reduction of labor needed in the cash crops

Plant disease management Most cover crops are in a different plant family than our cash crops. By allowing cover crops to grow a full season and become part of the crop rotation, disease and insect cycles can be broken. This results in increases of yields in the cash crops at lower labor costs, due to Buckwheat flowering in late July early August

A mix of peas and sweet clover


increased efficiency of harvesting and sorting. Some diseases and insects affect a variety of plant families. It is important to take great care when planning your rotation and to be aware diseases and insects that might be caused or carried by the cover crops. On the other hand mustard and sorghum can act as a bio-fumigant. Mustard and sorghum, when properly plowed under, can reduce incidences of Verticillium wilt, Rhizoctonia root rot, Fusarium wilt, and Pythium root rot. Overall farm diversity Most insects feed off the pollen of the grains and grasses when they are left to mature. In some instances, the cash crop acts as a host to beneficial insects. The pollen of the sweet corn is a good example as they provide food and habitat for the trichogramma parasitic wasp. For that same reason, parsnips can be left in the ground to flower in the spring. Dill, another member of the Umbelliferae family can serve the same function. After the dill is cut for market, the plants remain alive and produce flowers at a

time when the parsnips have gone to seed. Green manure crops provide a source of nectar to wild bees and we try to have at least on cover crop in full bloom during the growing season.

Disadvantages of cover crops:

Grains and alfalfa is a host for thrips, tarnished plant bug, and leafhoppers. Once the grain is combined or the alfalfa cut, the many insects including thrips and leafhoppers look for a new home. As we increased our acreage in grains and legumes our problems with thrips and leafhoppers increased. Our solution has been to have another crop available (besides the vegetables) for the insects to migrate to and to never mow all the cover crops at one time. Sod can provide a cover for the eggs of many insects. Flea beetle and carrot-fly take advantage of this environment over the winter. Another detriment from too much raw organic material is the residual activity in the soil that can have the same effects as fresh manure. Many diseases and pests like aphids increase when too much raw fertility is applied. We also noticed higher root rot ratings due to pythium or rhizoctonia as clover is a host to both diseases and esp. rhizoctonia thrives under high OM conditions. What we seed in different months in New York:

April and May: Bell Beans/Oats, Field-peas/Barley or Oats, Oats as nursing crop for Sweet, Red Ladino clover, or Alfalfa, Rye with Dutch White Clover and small Fescue Grass on head lands and harvest lanes (rye will not form a seed head when seeded in the spring). May and June: buckwheat, Japanese Millet or Sorghum-Sudan with Forage Soybean. July: Red clover, Buckwheat, Japanese Millet or Sorghum-Sudan with Forage Soybean, Annual Rye Grass. August: Red and Sweet Clover, Oats and Peas, Oats and Peas and Hairy Vetch. September: Rye and Hairy Vetch, Oats or Barley and peas, Oats and Hairy Vetch, Oats. October: Rye, Winter Wheat.

Sweet Blossom Clover in late June, early July

Dandelions flowering in late April


COST OF ORGANIC MATTER AT ROXBURY FARM: MOWING VERSUS COMPOST

Costs Hours used Acres used Cost per hour Roxbury

Cost per acre Total cost per year

Tractor 100HP 300 $ 50.00

Tractor 75 HP 300 $ 45.00

Rotary mower 15 feet 36 180 $ 47.50 $ 17.00 $ 3,000.00

labor $ 12.00

manure spreader 40 35 $ 22.00 $ 84.00 $ 2,900.00

harrow 12 feet 31 200 $ 25.00 $ 9.50 $ 2,000.00

grain-drill 25 70 $ 40.00 $ 23.00 $ 1,700.00

land $ 40.00

First we need to determine the cost of our equipment. Based on our limited use our costs are higher than the national average listed at most universities.

We know the cost of compost per yard and the value of minerals if purchased separately (OMRI listed). The remainder is the additional value of the OM. Spreading compost is significantly more expensive than mineral fertilizer as only a portion is plant nutrient, a large portion consists of water, silica and OM.

The two greatest factors in determining if green manures or sod are cost effective in raising the OM levels is dependent on the duration of the crop grown and the cost of land. If sod is hayed, we can add the sale of hay, but will need to deduct the cost of nutrients taken off the land to make a new analysis. Most lasting OM and N is formed in the soil by plant-roots.

C. Crop rotation:

Within the vegetable land we have a system of permanent sections, that each contains eight

beds. Permanent sections allow easier record keeping of where the crops have grown and aid in exact planning. There is no guesswork in finding where last year‟s crop was planted. The harvest lanes also serve as a means to easily reach to the cash crops, a place to pull in the irrigation reel, and as habitat for the bees (since they mostly contain white clover).

Crop rotation is a tool used to break insect, weed, and disease pressure in the vegetable fields.

There are many reports of increased yields of cash crops in fields that adopt rotations. In organic agriculture, we should not only rotate within the plant families of our cash crops but also include grasses and legumes in our rotation mix. As seen in the chart on page 8, they fix decent amounts of organic matter and introduce a broad spectrum of soil life to the farm. They can also form a habitat for beneficial insects. They are a neutral crop in our rotation since they rarely host diseases that affect our cash crops. Proper incorporation and time to let the soil digest the plant

Costs and return compost

yards cost per 20 yards cost of spreading value of minerals total cost cost per 1 K lb gain of OM

OM gain equal to 1 yr mowing

6 $ 150.00 $ 27.00 $ 87.00 $ 90.00 $ 100.00

Om gain equal to 2 yr mowing

14 $ 350.00 $ 60.00 $ 200.00 $ 210.00 $ 100.00

Om gain equal to 3 yr mowing

22 $ 550.00 $ 94.00 $ 314.00 $ 330.00 $ 100.00

Costs and return mowing

seeding per acre seed per acre mowing four times value of nitrogen land cost total cost cost per 1K lb gain of OM

One year $ 42.00 $ 60.00 $ 68.00 $ 108.00 $ 40.00 $ 102.00 $ 97.00

two years $ 42.00 $ 60.00 $ 136.00 $ 216.00 $ 80.00 $ 102.00 $ 44.00

three years $ 42.00 $ 60.00 $ 204.00 $ 325.00 $ 120.00 $ 101.00 $ 28.00


matter is important. Too much raw organic matter can greatly affect the health of our cash crops in a negative way. Introduction of bare fallow periods in “neutral” years are effective in breaking up both weed cycles and the incorporation of large amounts of plant matter.

The overriding factor in creating a field plan on

a CSA or other diversified farming operation is to have easy access to the crops. In order to give a minimum rotation of three years between the plant families we can choose to either plant all the same genotypes in one field or to expand our arable land to include more than vegetable crops. At Roxbury we rotate vegetable crops with grains, legumes, and grasses. Diseases prevalent in vegetables are generally not carried over by a grass or cereal crop and to a small degree by legumes (legumes can be the carrier of many soil pathogens or their plowdown can reinvigorate their development) Allowing for a diversity of families in one field creates more efficient harvesting conditions. In this method, the crew is able to harvest all the salad and cooking greens as well as the culinary herbs from one section, and moves to another field for the late morning harvest of cukes and tomatoes. As crops in the previous example generally mature around the same time, all the ground can be worked up in order to plant a cover crop.

At Roxbury the different plant families are:

Apiaceae or Umbelliferea: carrots, parsnips, parsley, celery, dill, etc Asteraceae or Compositae: all the lettuces, escarole, and certain cut flowers. Brassicaceae: all the Cole crops including broccoli, arugula, turnips, Chenopodiaceae: all beets, chard, and spinach. Convolvulaceae: sweet potatoes Cucurbiticeae: all cucumbers, melons, squashes etc. Fabaceae or legumes: peas and beans. Liliaceae or Alliums: all the members of the onion family Poaceae: all grains including sweet corn. Rosaceae: strawberries Solanaceae: all nightshades, including potatoes, eggplant, peppers,

tomatoes, etc.

Early morning harvest of greens and salad (picture P.Lowy 2002)

Shredding rye straw in between raised beds covered with corn

based mulch. Mulch provides weed control and protects the soil

Row covers to provide for insect and late frost protection.

Crops generally mature two weeks earlier with this method


These families are grouped into four different groups in one rotation:

Sweet-corn (25%)

Plasti-culture (25%) tomatoes, peppers, eggplant summer squash, cucumbers, melons Onions

Mixed veggies (40%) Two row crops like early broccoli, bok-choi, Chinese cabbage, collards, early kale, leeks, fennel. Three row crops like summer cabbage, mei-ching-choi, sugarsnap peas, summer beets, chard and broccoli rabe for bunching, tatsoi for greens, basil, parsley, head lettuce, and baby turnips Five or nine row crops like spinach, salad greens, braising mix, baby carrots, chard and broccoli rabe for leaves, tatsoi for salad, and herbs like cilantro and dill.

Snap beans (10%)

And in a different rotation for the Storage Crops:

potatoes (15%)

winter-squash (15%)

beets, carrots, parsnips, celeriac (20%)

green and red cabbage, rutabaga, kale, collards, cauliflower, fall broccoli (40%)

Sweet potatoes (10%)

All crops incl. sweet corn are planted in blocks 50 feet wide

allowing for good access with harvesting, irrigation and pest

control. European Corn borer is controlled with parasitic wasp

and the application of entrust with a one sided boom sprayer.

kale, broccoli and cauliflower planted after a crop of bell

beans. No other fertilizer is applied to produce 4 lbs heads of

cauliflower. Imported cabbage worm is controlled with Dipel

DF


Record keeping for crop rotations in MS Excel:

Steps for Creating a DATA sheet. 1. To name the sheet go to Format at the top of the page and click on Sheet. Then click on

Rename. Type in the name of your field and DATA.

2. Then create a table for each section of your field. Each row in the table will represent a bed in the section.

a. At the top of the table create your Data headings. We use SECTION, BED,

CURRENT PLANTING, DATE, PREVIOUS PLANTING (in case of multiple plantings in one season) COVER CROP, AND DATE.

b. In the table you can use color to separate the data to make reading easier if you prefer.

c. In the DATE columns the cells need to be formatted for the date. Go to Format at the top of the page. Click on Cells. Then click on the tab for Number. The choose Date from the list. Pick the format for how you want the dates to appear.

3. Highlight the whole table and then to copy use Control C. Then paste a table for each of

your sections in the field by pushing Control V. 4. Now the tables are set up for recording your crop data.

Sample data sheet:

Roxbury Farm HOME MAP

2006

Lindenwald Field

SECTION BED CURRENT PLANTING DATE

SECOND PLANTING DATE

COVER CROP DATE

1 1 1st Peas 26-Mar Lettuce 15 23-Jul none

6 bu 2 1st Peas 26-Mar Lettuce 15 23-Jul none

48 3 1st Peas 26-Mar Dill, Cilantro 16 30-Jul none

4 1st Peas 26-Mar Lettuce 17 6-Aug none

5 2nd Peas 2-Apr Lettuce 17 6-Aug none

6 2nd Peas 2-Apr Lettuce 16 30-Jul none

7 2nd Peas 2-Apr Lettuce 16 30-Jul none

8 2nd Peas 2-Apr Spinach 16, 17 30-Jul none

SECTION BED CURRENT PLANTING DATE

SECOND PLANTING DATE

COVER CROP DATE

2 1 Chard 9-Apr Spinach 21 3-Sep none

6 bu 2 Scallion 1 9-Apr Spinach 21 3-Sep none

48 3 Chard 2 23-Apr Lettuce 21 3-Sep none

4 Scallion 2 23-Apr Lettuce 21 3-Sep none

5 3rd Peas 9-Apr Lettuce 21 3-Sep none

6 3rd Peas 9-Apr Lettuce 20 27-Aug none




Steps for Creating Maps

1. To name this sheet go to Format at the top of the page. Click on Sheets and then Rename. Type in the name of your field and MAP.

2. Go to Tools at top of page & click on Options. Under Options click on the Gridlines box

so that the check mark disappears. Now you will have a blank screen.

3. The width of columns needs to be narrower. Go to Format at top of page & click on Columns. Then click on Width and type in desired width. I use 3.

4. Create your first section.

a. Each column represents one bed in the section. To outline the section and each bed use the Outline box at the top of the page.

b. First highlight the boxes for the length of the left side of your section. Then click

on the arrow next to the Outline Box and choose the Left Outline.

c. Next highlight the boxes for the bottom side. Go over as many columns as you have beds per section. Then click on arrow next to the Outline Box and choose the Bottom Outline.

d. Then outline the right side & the top.

e. Next to separate the beds in the section highlight each column within the box you

just created and outline one side.

5. Number each bed in the section.

6. Now merge cells and align the text for the data that will be entered later. a. Highlight 5-6 cells in one bed in your section. b. Go to Format at the top of the page and click on Cell. c. Go to the Alignment tab. Then click on the box next to Merge cells and the box

next to Shrink to fit. d. Then change the alignment of the text to 90 degrees. e. Highlight the cells you merged and copy them by using Control C. f. Highlight the cells in the next bed and paste by using Control V. Do this for the

rest of the beds in the section.

1. Now each cell in the section needs to be linked to the data cell they correspond to on the DATA sheet.

a. Click on your merged cells in the first bed in the section. Then go to the formula bar at the top of the page and click on the = sign. Then type:

„Field Name DATA‟! Column letter cell name e.g. „Field DATA‟!D6 then click OK

b. To copy this into the rest of the beds, highlight „Field DATA‟!D6 (not the equal sign). Then push Control C to copy. Push tab to get to the next bed and go to the Formula bar and click on the equal sign. Then push Control V and the copied information should be in the formula bar. Then click OK and copy the information into the next bed. Repeat for the rest of the beds in the section.

2. Now copy the whole section by highlighting it and pushing Control C. Then paste a

section for each section in your field by pushing Control V.


3. Now you need to change the cell numbers in the formulas to correspond with the correct cell number on the Data Sheet.

a. Click on the merged cell in the bed. Click on the formula bar at the end of the information. Delete the incorrect cell number and Column letter if needed and type in the correct information.

b. Then click Tab and move to the next bed. Repeat for all beds in all sections in the field.

You can add your field name and include trees, roads, creeks, and other landmarks by filling the cells with different colors. Sample Map sheet:

Roxbury Farm DATA

2006

Section 1 Section 2

5.8 bu/bed 44.8 bu 5.8 bu/bed 44.8 bu

1st P

eas

1st P

eas

1st P

eas

1st P

eas

2nd P

eas

2nd P

eas

2nd P

eas

2nd P

eas

Chard

Scalli

on 1

Chard

2

Scalli

on 2

3rd

Peas

3rd

Peas

3rd

Peas

3rd

Peas

1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8

ROUTE 9H


Use the following rotations as an example:

Here we have a five year rotation in the storage vegetable group. The peas/barley/bell beans fix the needed nitrogen for the following cole crops which are considered heavy feeders. Summer weeds are very well controlled in that year but a spring fallow is needed to flush out the spring weeds for the receding potato crop. Sorghum is used as a bio-fumigant to reduce rhizoctonia and scab in the potatoes, and black rot in the winter squash. The potatoes and winter squash are followed with rye and vetch which are harvested for straw to be used in the plasti-culture. A summer fallow is needed to prepare land for carrots and parsnips. Oats is seeded not until Sept 1to avoid excessive growth.

Year 1 Year 2 Year 3 Year 4 Year 5 year 6 Year 7

Spring

oats, red and

sweet clover

red and sweet clover

oats and peas

remains

rye and vetch

Spring veggies

spring bare

fallow

rye and vetch

Summer red and sweet clover

sweet corn

plasti-culture

summer bare

fallow

summer veggies

green beans

summer bare

fallow

Fall red and sweet clover

oats and peas

rye and vetch

oats and peas

fall mixed veggies

rye and vetch

fall mixed veggies

Here the ground is prepared to provide sweet corn with the necessary nitrogen to support good growth. The sweet corn is an excellent crop to precede the plasti-culture crops as sweet corn does not serve as a host to the many diseases affecting the Solanaceae and cucurbits while weeds are generally under good control. The following rye and vetch is harvested for straw and a bare fallow is introduced to clean up the seed bank that generally builds up during a plasti-culture cycle. The mixed vegetable grown in year 5 are often double cropped as a fine seed bed with little plant residue is required for optimum seeding and weed control. The following year a crop of green beans is followed with another crop of rye and vetch. this is again harvested in year 7 for straw and followed by a summer fallow to create good planting conditions for a seeded crop of fall vegetables.

Year 1 Year 2 Year 3 Year 4 Year 5

Spring peas/

barley/bell beans

spring bare

fallow

oats potatoes/

winter-squash

rye and vetch

spring bare

fallow

Summer Broccoli/

cauliflower/ kale

Sorghum Sudan Forage

Soybean

potatoes/ winter-squash

summer bare

fallow

carrots, celeriac, parsnips

Fall Broccoli/

cauliflower/ kale

Late summer

bare fallow oats

rye and vetch

oats and peas

carrots, celeriac, parsnips


Disease problems and efficacy of a Crop Rotation:

disease Strain Common name Rotation Length Affected Crop

Alternaria brassicicola early blight yes 4 years cole crops

Alternaria cucumerina leaf blight yes 4 years cucurbits

Alternaria solani early blight yes 4 years tomato, potato

Alternaria dauci early blight yes 4 years carrots

Ascochyta rhizoc wet weather blight yes 4-6 years parsnip

Ascochyta pisi seedling blight yes 4-6 years peas

Botrytis cinerea botrytis blight yes/no 2 years many crops

Bremia lactuca downy mildew yes 2-4 years lettuce

Cercospora beticola leaf spot yes 5 years beets

Cladosporium cucumerinum Scab yes 4 years cucurbits

Clavibacter michiganensis bacterial canker yes 6 years tomatoes

Colletotrichum lagenarium anthracnose yes 2 years cucurbits

Colletotrichum lagenarium anthracnose yes 2 years bean/cucumber

Colletotrichum coccodes anthracnose yes 2 years tomatoes

Didymella bryoniae black rot, gummy stem blight

yes 3 - 4 years cucurbits

Erwinia tracheiphila bacterial wilt yes/no 2-4 years cucurbits

Erwinia carotovora potato soft spot yes 4 years potatoes

Erwinia stuarrti corn stewart's wilt no flea beetle corn

Erysiphe cichoracearum powdery mildew no airborne cucurbits

Erysiphe cruciferarum powdery mildew no airborne cole crops

Erysiphe lycopersici powdery mildew no airborne tomatoes

Erysiphe pisi powdery mildew no airborne carrots, parsnips

Erysiphe heraclei powdery mildew no airborne beets

Erysiphe taurica powdery mildew no airborne solanaceae

Fusarium oxysporum fusarium wilt yes/no wind/equipment cucurbits

Hyaloperonospora parasitica downy mildew yes 2-4 years cole crops

Itersonilia itersonilia black canker yes 4 years parsnips

Phoma lingham black Leg yes 4 years cole crops

Phytophthora capsici phytophthora blight yes 4 -5 years peppers, cucurbits

Phytophthora Infestans late blight no freeze/airborne tomatoes, potatoes


Disease problems and efficacy of a Crop Rotation:

disease Strain Common name Rotation Length Affected Crop

Plasmodiophora brassicae clubroot yes 7 years cole crops

Plectosorium tabacinum downy mildew yes/no 4 years

airborne

Cucurbits

Podosphaera xanthii powdery Mildew no airborne Cucurbits

Pseudonomas marginalis brown interirors yes 2-4 years parsnips

Pseudonomas syringae pv lachrymans

angular leaf spot yes 2-4 years cucurbits

Pseudonomas syringae bacterial speck yes 2-4 years tomatoes

Pseudoperonospora cubensis downey mildew no airborne cucurbits

Puccinia sorghi corn rust no airborne

Pythium damping off, root rot

yes ? seedlings, many hosts

Rhizoctonia solani root rot, belly rot,

yes 10 years cabbage, lettuce,

black rot potato, tomato

Rhizomonas suberifaciens corky root yes 2 years lettuce

Sclerotinia sclerotiorum white mold yes 5-10 years beans

Sclerotinia sclerotiorum watery soft rot yes 5-10 years cabbage

Sclerotinia sclerotiorum drop yes 5-10 years lettuce

Sclerotinia sclerotiorum stem rot yes 5-10 years tomato potato

Septoria lycopersici septoria Leaf spot

yes 4 years tomato

Septoria lactucae blight yes 4 years lettuce

Stemphylium oleraccea stemphilium leaf spot

yes 4 years spinach, clovers

Streptomyces ipomoea soil rot (pox) yes 6 years sweet potato

Ustilago maydis corn Smut no airborne

Verticillium albo-atrum verticillium wilt yes 13 years eggplant, many hosts

Xanthomonas campestris pv. phaseoli

bacterial leaf spot

yes 2-4 years lettuce,peas

Xanthomonas campestris pv. vesicatoria

bacterial leaf spot

yes 2-4 years peppers,tomatoes

Xanthomonas campestris pv. campestris

black rot yes 2-4 years cole crops


Insect Problems and efficacy of Crop Rotation:

Insect Common name Rotation Length Affected Crop Notes

aphid, cabbage limited 1 year cole crops limit on nitrogen fertilizer

aphid, corn leaf limited 1 year sweet corn limit on nitrogen fertilizer

aphid, green peach limited 1 year many crops limit on nitrogen fertilizer

aphid, melon limited 1 year cucurbits, pepper, eggplant limit on nitrogen fertilizer

aphid, pea limited 1 year peas, favabeans, lentils overwinters on clover

aphid, potato limited 1 year potato, many host plants limit on nitrogen fertilizer

armyworm, common no cole crops migrates from south

bean leaf beetle yes 1 year soybean

cabbage root fly yes 1 year cabbage, broccoli

cabbage looper no 1 year cole crops migrates from south

carrot weevil yes 2 years carrots

carrot rust fly yes 1 year carrots plant upwind

Colorado potato beetle yes 1 year potato, eggplant plant succession far away

corn ear worm no 1 year sweet corn migrates from south

cross striped cabbage worm yes 1 year cole crops plow under plant debris

cucumber beetle spotted yes 1 year cucurbits overwinter at edge of field

cucumber beetle striped yes 1 year cucurbits use trap crops

cutworm black no many plants fall plowing, weed control

cutworm variegated no many plants both cutworms are migratory

diamond back moth yes 1 year cole crops plow under plant debris

European corn borer yes 1 year sweet corn, peppers shred stalks in fall, plow under

fall armyworm no 1 year sweet corn migrates from south

flea beetle Corn yes 1 year sweet corn plant succession far away

flea beetle crucifer yes 1 year cole crops plant succession far away

flea beetle eggplant yes 1 year eggplant, potato plant succession far away

fungus gnats no potting soil, many hosts hygiene in greenhouse

imported cabbage worm limited 1 year cole crops can fly large distances


Insect Problems and efficacy of Crop Rotation:

Insect Common name Rotation Length Affected Crop Notes

Japanese beetle no 1 year basil, corn, can fly large distances

leaf miners yes 1 year beets, chard, spinach weed control

leafhopper Aster no 1 year lettuce windblown from the south

leafhopper potato no 1 year potato, lettuce, snap beans

migrates from south

maggot cabbage yes 1 year cole crops can fly large distances

maggot onion yes 1 year alliums can fly large distances

maggot pepper yes 1 year peppers can fly large distances

maggot seed corn yes 1 year sweet corn can fly large distances

Mexican bean beetle yes 1 year snap beans plow under plant debris

mite, two spotted spider limited 1 year tomato, pepper, melons many host plants

sap beetle limited 1 year corn, melons

squash bug yes 1 year summer squash, cucurbits plant succession far away

squash vine borer yes 1 year cucurbits

stalk borer common yes 1 year tomato

stink bug limited 1 year many plants overwinters in sod and hedgerows

tarnished plant bug limited 1 year strawberry, lettuce many hosts, weed control

thrips onion limited 1 year alliums, colecrops manage hayfields

tomato hornworm limited 1 year tomato can fly large distances

whitefly yes 1 year lettuce, tomatoes hygiene

wireworm yes many crops when issue reduce fresh OM input


D. Biodynamic preparations:

Within the management practices of the biodynamic preparations we can distinguish two different types of applications. 1. The compost preparations.

The use of biodynamic preparations in the compost allows plants to become healthier, not

only in the field but also more nutritious as food or feed. When you make compost, the original materials (which can be manure, woodchips, horse bedding, plant waste etc.) transform into something completely new. The original organic materials disappear to create a complete new substance. The original ingredients and the management of the pile determine the quality of the compost. In organic certification frequent turning is required to ensure that harmful pathogens are adequately destroyed. The disadvantage of this is similar to frequent tillage of the soil; we tend to burn up the pile creating greater losses of organic matter than when we allow it to break down a more natural way.

The compost pile is an opportunity to manage the decomposition processes on the farm.

Organic materials are constantly consumed by different organisms at every different state of decomposition. Certain types of bacteria, fungi, actinomycetes, nematodes, mites, snails, slugs, earthworms, millipedes, etc. are the primary consumers of the organic materials in the compost pile. That is because they live off the manure, grass clippings, leaves, wood chips etc. But as our primary consumer group gets established they quickly become the food source of another group of organisms. Springtails, certain mites, beetles, nematodes, protozoa, rotifera, and soil flatworms live off the first group and are called the secondary consumers. Finally this group gets eaten as well by centipedes, predatory mites; rove beetles, fomicid ants, and carabid beetles which we call the tertiary consumers. The density of animal life in the compost pile is like a high-rise in the city. This complexity of organisms requires management just like any other animal we keep on the farm.

The decomposition processes are like other

digestive processes. Digestive systems in higher organism are regulated by our organs. In biodynamic agriculture the preparations help regulate those processes in the compost pile. The compost preparations can be compared to organs or bodily functions that regulate the digestive processes in the compost. Each preparation provides a different quality and Steiner chose from a variety of plants with balancing qualities. These herbs combined with certain animal parts are first fermented and "charged" in a particular way to be added in minute quantities to the pile. They work by radiating out a positive channeling of forces that support the decomposition of the organic materials. In general the preps organize the life forces and are sometimes referred to as bio-organizers. For every ton of organic material a pinch of chamomile, yarrow, oak bark and yarrow is inserted at all four corners of the pile, while nettle is placed in the middle. The handle of a rake can be used to create a tube like opening that allows us to insert the preparation into the pile. In the middle we place the nettle (which can be used more abundantly), while the valerian is mixed with lukewarm water and sprayed on the surface of the pile.

inserting the compost preparations using the handle of a rake


There are six different compost preparations: For a more thorough insight the reader is referred to the original source which is Planetary Forces and Life Processes by Bernard Lievegoed PhD MD

The chamomile preparation is

associated with the planet Mercury. Mercury stands for mobility, agility, and sensitive chaos; a movement without direction but willing to flow into every crevice available while taking up its form. Bernard Lievegoed compares the planetary qualities the preparations bring to the farm to the planetary qualities in people. . People can be described as being endowed with certain planetary qualities. For example in people, Mercury works through the lymphatic system and lymph vessels, and is related to humor. The comedian draws from what can be considered mercurial qualities; by having the ability to make funny faces, to have wit and a sense of humor, and to allow things to keep moving draws from mercurial qualities. Good sales persons or politicians show these qualities in their ability to be realistic and to rapidly adapt to a new situation. In its desperation those qualities can become deceitful, and here we see the relationship of Mercury to Hermes, the Greek mercurial God of traders and thieves, who are alike in the way that they remain all earthly possessions in motion.

Chamomile preparation is made of the dried chamomile flowers (Matricaria chamomilla or

Matricaria recutita). Most seed suppliers sell the common chamomile which is also called German Chamomile and available from sources like Environmental Seed Producers in Lompoc, California. According to the USDA database German or common Chamomile grows wild in the Northeast. When we use purchased in instead of cultivated chamomile, we cannot be assured that it is of the common type. The question is also in how fresh the supply is and how vibrant the flowers are. When grown on the farm, chamomile needs to be harvested on a daily basis with a comb (available at Johnny Selected Seeds) to ensure the use of young flowers heads. The flowers need to be dried as quickly as possible without losing any of their aromas.

The finished preparation is a substance that works in the processes of potash and calcium in

the soil, while in the treated manure it creates greater stability of its nitrogen content. Applied compost helps plants to better take up potassium and calcium. Crops grown on treated land are healthier and more nutritious with the help of the chamomile preparation.

In the fall before we use the flowers, we will need to briefly soak them in lukewarm

chamomile tea. This substance is then placed in freshly obtained intestines of a cow. A freshly slaughtered cow is recommended. We avoid using any intestine from a cow that was recently fed grain. If there is a lot of food stuff in the intestines we carefully flush them out with water. Also here we do not know exactly how the decomposition process works but it works better when we work with fresh intestines. We can choose to first blow the intestines up with a straw (like we do with the stag bladder) which makes stuffing with the flowers afterwards easier. The stuffed, so-called sausages are then placed in the soil and kept there over the winter in a place where snowdrift collects. Always bury the preparation in deep soil like we can find in a fertile garden.

The dandelion preparation is associated with Jupiter. Jupiter is the sculptor of the

world and stands for beauty, wisdom, and the ability to have oversight. Philosophers are endowed with strong Jupiter qualities. While a person endowed with Mercurial qualities lives


in the valley occupied with all infinite details, a person with Jupiter qualities would be on a hilltop having the best view of the world. In our body we recognize Jupiter by the roundness of our skull or the ball shaped joints of the shoulder, knee, or hip. On the other hand Jupiter is also associated with surface tension that allows our muscles to function. In the plant world this surface tension is facilitated through the silica processes.

The dandelion preparation is working

through the compost by endowing the soil with wisdom. The thought is that all the positive influences from stream, pond, forest, meadow and fields become available to the plant through the soil amended with compost treated with the dandelion preparation. The idea is that those soils will better be able to absorb cosmic forces needed to vitalize the farm as a living organism.

The preparation is made from the dried dandelion (Taraxacum officinale) flowers. The

flowers are picked in the morning. Only the flowers that have not yet fully opened are useful. When they are dried, the flowers that are too mature would enter the seed stage. When we make this preparation in the fall, we start by soaking the flowers in lukewarm dandelion tea. The next step is to place this substance in little bags that we form out of the mesentery of a cow. The mesentery should be free of fat since that would inhibit proper transformation once it is placed in the soil. Also, when the bags are too large, there is a chance that the substance will turn into silage. A good size is about the size of a tennis ball or of a small flat sized package. These pockets are then buried like the chamomile preparation.

The yarrow preparation is associated with

Venus. Venus stands for care and reception. People with Venus qualities have good parenting skills, and a good

ability to nurture and host. People with strong Venus qualities are good listeners, and are able to create a space so others can fill it. Venus allows the conversation to take place. Think of the ability of a chalice to hold wine; it can only do so because of its hollow shape and it is open to what comes from above. Think of Venus as the hollow body of a violin that creates the resonance of the sound created by the friction between the strings and the bow.

The yarrow preparation Should give the treated manure the ability to vitalize the soil. It

should give the earth the qualities to absorb minute quantities of trace minerals out of space. Steiner mentions in the "Agriculture Course" that the mere presence of yarrow will have positive influences on a farm. The yarrow preparation is involved in the processes where potassium is involved in stem formation and sturdiness.

The preparation is made in the early summer with dried yarrow (Achillea millefolium) flowers

that are briefly soaked in lukewarm yarrow tea. Yarrow flowers are harvested over the previous summer when the flowers are in full bloom. The soaked dried flowers are placed in


the bladder of a stag and hung on the south side of a barn. The bladder can be enlarged by being inflated and tied down to maintain its shape. In the fall the bags are brought down and are buried over the winter months in fertile topsoil.

The nettle preparation is associated

with Mars. Mars stands for forcefulness and it is no surprise that nettle helps plants in the processes of growth. Mars represents growth especially in the sprouting buds. It is best described as movement with clear and concise purpose. Think of an athlete throwing a spear or a musician drawing the hairs of a bow across the strings of a violin. It is in the friction between the two that sound is created. Mars becomes visible in the resistance of its force. The air meets this resistance on our vocal cords, the spear in the target, and the hairs of the bow on the strings of a violin. People with strong Mars qualities are poor caretakers often allowing something to be destroyed in order to make space for their fertile and creative ideas and initiatives. While Mars speaks, Venus listens; together creating a conversation. In many different cultures these two symbols have been representative of the male and female element in nature. An ancient symbol for Venus is V, while Mars is symbolized with Λ.

The nettle preparation has a strong relationship to the iron processes in the plant and its

ability to form proteins. The soil treated with nettle preparation becomes individualized to the crops we intend to grow with higher nutrition values. Although it is not considered a biodynamic practice, some people use the nettle fresh as a compost tea with good result. The nettle‟s properties is said to increase growth when applied as a foliar spray. I personally do not have any result with this but

Nettle preparation is the easiest to make and can also be used as a foliar spray. The nettle (Urtica dioica) is harvested before the flowers go to seed. It is then directly placed in the earth, but not in direct contact with it. We place a layer of peat moss between the nettle and the moist earth. It is left there for a full season (summer and winter), and is then dug up and used as a preparation in the compost pile. Nettle does not need an animal organ but is often placed in a ceramic pipe to help us locate the finished preparation. Often when the nettle is buried with some peat moss it takes a lot of effort to separate the garden soil from the preparation. As with all the preparations we need to ensure that plant roots cannot grow into the preparations so we prefer open garden soil over a perennial plant garden.

The oak bark preparation is associated with the moon. We can

think here of the moon‟s ability to reflect the sun. When we consider moon quality we think of the ability to adjust by means of reflection. Moon forces work in reproduction and genetics and find their boundaries in our skin. Some actors are blessed with strong moon qualities as moon qualities determine our skin, our ability to imitate, and our sexual attraction to each other. While the moon represents growth (almost without boundaries) it also dampens growth by creating better boundaries. Just as our body is contained


by our skin, moon forces are retained in nature by the other aspect of those same moon forces in its quality to reflect and differentiate.

Oak bark preparation works on the farm by containing healthy growth and by giving it

boundaries. This preparation will, if made properly, give the compost a disease suppressing quality. Oak bark preparation works in the calcium processes of the plants. Calcium in the plant is found in the cell walls and insufficient amounts will lead to poor resistance to diseases. While bark in general forms a protective layer on the tree to protect the cambium, the oak bark is high in calcium.

Oak bark (from Quercus robur - English oak in Europe, Quercus alba -white oak, or Quercus bicolor-swamp oak in the US) preparation is made of finely ground-up oak bark that is put inside the skull of a freshly slaughtered cow or other bovine animal. The oak bark is taken from a white oak and only the living part of the bark (which lies directly underneath the dead part) is harvested. The harvested oak bark is finely ground up (an old coffee grinder works great). When we use a fresh skull we need to remove all flesh and other living parts. Great care is taken when the brains are removed to make place for the oak bark. You can use a long spoon or flush them out with a hose. After the oak bark is inserted into the cavity we cover the hole up with a piece of bone making sure we do not seal off the opening. The skull is then placed in moving water that preferably has a somewhat mucky nature. We can choose to seal off the foramen magnum with clay as well as bone so that the ground oak bark is not washed out by the moving water. There are many other, smaller foramina, however, so with this method the water can still get in contact with the water. In the spring the skull is taken up and the composted oak-bark removed. The transformed matter will be dark brown to black and will have little smell left.

The last is the valerian preparation which is

associated with Saturn. Scientists and accountants are endowed with strong Saturnal qualities as they tend to work in the past, although this is only partly how Saturn works in us. It is about incarnating the spirit into substance. Saturn stands both for death and resurrection. In our body Saturn is represented by our skeleton. Our bones are formed through a process of crystallization, representing dead tissue, while its core, the bone marrow creates new life in the form of blood. The Valerian preparation helps the soil absorbing those cosmic forces allowing the plant to express their archetype.

The valerian acts like a skin and contributes an

element of warmth to the pile. In the spring I take advantage of this ability by spraying the valerian tincture on tender plants to protect them from early morning frost.

Here we use the fresh flowers of Valeriana officinalis

as the juice is pressed out. The timing is when the plants are in full bloom (August/September). You can best use a press to squeeze the juice out of the flowers as we want to end up with a clear liquid. There are two variations available: one is fermented, which I prefer, and the other is bottled up the way it comes out of the press. The smell of the fermented valerian is absolutely wonderful. This preparation is like the nettle made without an animal component. The finished tincture is diluted in lukewarm water, stirred vigorously and sprayed onto the compost pile.


2. The field sprays:

The horn-manure and horn-silica

preparations are both made with the horn of a cow.

The field sprays are associated with the

sun each in their own particular way. While the horn manure works through root system and organic matter (organic matter and roots is in effect stored sunlight ), the horn silica works with the direct influence of light from the sun by improving photosynthesis.

Great care is taken in what location the

preparations are buried. The ideal location is where snow usually accumulates. The processes in a fertile soil covered deeply under a snow cover allow for the best conditions for proper transformation.

In the fall we make the horn-manure preparation.

Horn manure directly influences the way

organic matter is transformed in the soil. Its positive influences are similar to what organic matter and phosphorus does to root development of our crops. In general, we notice that horn manure works on germination, root development, and growth. Also called preparation 500, it has shown to increase rooting depth of both cash and cover crops while providing better conversion from raw organic matter to humus (building long lasting soil fertility).

Here we prefer to use cow manure and we select cow pies with enough form whereby the shape of the intestines are somewhat visible. Avoid using pies that have too much shape like that of sheep-manure. We stuff the manure into the horns and then bury them in the ground with the points of the horns sticking up to avoid rainwater running in. In the month of May this preparation is dug up. The substance in the horns has by then become odorless. If there is a smell to it or if it still looks like manure, then you know that it has not been properly transformed. Before this preparation is applied to the fields as a spray, we have to dilute it in lukewarm water. About a tennis-ball size quantity per thirty gallons of water is sufficient. This is stirred vigorously in one direction until a vortex is formed, and then the direction is reversed and stirred in the opposite direction to create another vortex, etc. The total time of stirring is one hour. The solution will now start smelling again, not like manure, but definitely alive. For filtering the liquid I found paint bags to work best. Filtering avoids wasting time in the field cleaning spray-nozzles. Our 3.5 gallon backpack sprayer covers about one acre. This preparation is sprayed directly on the soil, previously to tillage in spring or in the fall on hayfields.


The Horn-Silica preparation makes use of a cow-horn again filled with finely ground

Silica. This is then placed in the ground during the summer months. A much smaller quantity than the horn manure, no more than a pea-size amount, is stirred vigorously in 30 gallons of water for one hour. This solution is sprayed directly on the plants. The Horn Silica has a strong connection to the light and warmth forces of the summer. Its positive influences are similar to what the summer sun contributes to the plants. It slows down growth but increases the overall plant mass. Plants treated with this preparation are shown to have better taste and keeping qualities. All preparations including horn-manure should be stored in peat moss in a dark, cool and damp place, with the exception of horn-Silica which is left in a glass jar on a windowsill.

4. Soil Chemistry

To properly discuss the nutritional needs of plants we need to realize that of all the substances

that are taken up by plants, minerals make up the smallest, while carbon and hydrogen and oxygen make up the greatest fraction. Carbon-dioxide is taken up by way of diffusion out of the air by the leaves stomata‟s while water (hydrogen and oxygen) and minerals are taken up by the roots out of the soil. Water is absorbed by means of osmosis. The mineral solutions in the roots have a higher concentration of salts than the soil which allows the plant to absorb soil moisture with a slightly lower level of minerals. Consequently, when soluble fertilizer is available in high concentrations around the roots, the plants are unable to absorb water. High salt content can cause the roots of a plant to “burn”. In extreme situations it will cause the plants to die. We have observed this at times in the greenhouse when the potting soil had a high concentration of soluble salts (not just sodium).

In biodynamics we make a distinction between plant

nutrition that is cosmic and plant nutrition that is terrestrial. Minerals come from the earth while the sun and other cosmic bodies give the plant the strength to absorb water, carbon and minerals. The energy from the sun is cosmic and its forces that are partly visible as light have an important influence on the quality of the crops we raise. All living organisms absorb the sun‟s energy either directly or indirectly. Silica plays a facilitating role between the sun‟s energy and all forms of life on earth. It is not a coincidence that we find silica in the periphery of all things; in the xylem of the cell walls, in skin and hair and Silicon makes up of 28% of the crust of the earth. Silica can be considered the mineral that is the medium between the cosmic and the terrestrial. While it is very much part of the earth, it does not interact much with its environment. It does not get involved chemically, as it is neither positive nor negatively charged. It cannot hold nutrients and is considered to be merely an aspect of the soil as an aggregate. It is not difficult to accept that some people have come to believe that silica is merely a medium that contributes porosity to hold air and water for plants to grow in.

The challenge as a farmer is to balance the energy of the terrestrial and the cosmic. The two are

a team as their combined energy provides for healthy plant growth. Once minerals are released in a soluble form the plant has less ability to differentiate. In biodynamics we recognize the need

sun solar coronal mass ejection

http://images.google.com/imgres?imgurl=http://www.geog.ucsb.edu/~jeff/wallpaper2/sun_coronal_mass_ejection_2-4days_later_hits_earth_field_lines_30million.jpg&imgrefurl=http://www.geog.ucsb.edu/~jeff/wallpaper2/page3.html&usg=__SpoGRux6Z6wTlw1h_nGyVaT4rAw=&h=1024&w=1280&sz=120&hl=en&start=7&sig2=mqg-ntbXrvBSr2YJGks-Xw&um=1&tbnid=SGAakzwThcTqJM:&tbnh=120&tbnw=150&prev=/images?q=sun+and+earth&imgsz=l&hl=en&rlz=1T4ADRA_enUS360US360&sa=X&tbo=1&um=1&ei=IAdBS9CuM8TT8Qbu2MiOBw


for proper nutrition, but the addition of fertilizer is seen as a temporary remedy. In a biologically healthy soil, nutrients are carefully recycled and a good portion of crops in the rotation are effective carbon and nitrogen fixers, while others crops are selected to retrieve minerals from the subsoil. As microorganisms play a large role in helping plants to absorb minerals, a biodynamic farmer hesitates in upsetting the delicate balance that would destroy these ecosystems. Reduced tillage and the recycling of manure are important components in sustaining the soil ecology and contributes to the aim of reduced inputs.

Plant nutrition can be viewed from many different perspectives and the different approaches can

appear contradictive to each other creating more confusion than clarity. At that point it will be good to remember one interesting point; while malnutrition causes many problems and deaths in the developing world; ample nutrition has become the main cause of death in the rich industrial world. Lawrence D. Hills (the renowned British organic gardener) is quoted by saying: "We are starving to death on a full stomach ". The modern nutritional approach tends to focus on the individual components that only combined provide us with nourishment. The following information needs to be placed as one aspect that combined with a holistic approach make for good soil, plant and animal health.

There are many different approaches when it comes to determining the correct or optimum

amount of nutrients in the soil. The first approach is from Justus von Liebig who claimed that: “The yield of a crop is determined by the growth factor of the least available nutrient”. It is called “the law of the minimum” as yield can only be improved when the nutrients that are least available are increased. It implies that yield losses are caused by mineral deficiencies. Von Liebig‟s approach is like fixing the weakest link in the chain.

Another approach is from Mitscherlich who formulated his law of growth effects this way: “The

yield of a crop is determined by every factor that is not optimum. The further a factor is removed from its optimum, the greater its influence”. This means that nutrients can lead to yield losses when their availability is either excessive or deficient to plants.

The well known American soil scientist William Albrecht believed that the available nutrients

should be optimized based on their percentage of the total saturated base. In other words to achieve adequate plant nutrition an appropriate balance of nutrients in the soil is necessary. In his approach calcium should take up 65 -70% of the available cations, magnesium 10%, and potassium 3% - 5%. His studies showed that in areas west of the Mississippi river where rainfall is less than 25 inches per year, minerals like calcium are in abundant supply creating conditions for good grass and legume development. As grasses and legumes that are rich in protein are the source for muscle development of ruminants, he explained the rich development of the bison on the prairies is due to the suitable chemical composition of the soils. We have seen that optimum calcium conditions allow for better development of the legumes like clover and alfalfa. As a good stand reduces weed development the Albrecht approach has become a tool to eliminate weeds in our cover crops. We have also learned to cut back on compost to avoid build up of potassium which can contribute to excessive weed development (galansoga, chickweed, and purslane), while we are aware that an excess of calcium can result in making nutrients unavailable.

Spreading gypsum to increase Ca levels


Another approach is at times being credited to Mitscherlich. This is the most widely used

methodology which I believe should be credited to farm economists instead of soil scientists. Here it is recognized that “the increase of a growth effect does not have an even relation to yield and therefore return”. In other words each extra bag of fertilizer used produces less of a return on the expense. This phenomenon is therefore called the law of the diminishing returns. The widespread ecological problems of agriculture are due to this approach as fertilizer has been a subsidized product and farm economists base the cost of fertilizer on the cost of fertilizer to the farmer. Once the true cost of runoff and pollution is factored in we will realize that the increased yield of crops comes at a very high price. As organic farmers we need to rely more on a healthy soil to produce abundant crops so a diminishing return is reached at far lower levels.

Soils with a high natural fertility reach this diminishing return at far lower application rates

compared to poorer soils. Sandy soils low in organic matter is usually low in nutrients and will require more fertilizer to obtain a satisfying yield.

Nevertheless no matter what your approach is, the export of minerals and other nutrients from

your farm needs to be replaced. Most of us are faced with a serious deficit of organic matter, and nutrients as the previous farmer depleted the land with poor farming practices. In this case we need to import nutrients (including carbon) into our farm to create the proper conditions for a farm as a healthy organism.

The above graph shows the complete nutrient removal of all the plant parts. What we need to

realize here is that depending on the crop certain parts esp. the roots are left in the field. When

Nutrient removal by crops

N P K

Vegetable crop Asparagus

11 3 6 Beans at 5,000 lbs per acre

170 16 100 Beets

140 14 140 Broccoli at 10 M lbs/acre

165 10 210 Brussels Sprouts

240 30 235 Carrots at 30M/acre

145 25 345 Cantaloupe at 22,5M/acre

155 27 155 Celery at 50M./acre

195 50 425 Lettuce at 20M/acre

95 12 170 Onion at 40M/acre

145 25 155 Peas at 4M/acre

170 22 80 Pepper at 22,5M/acre

140 12 140 Spinach at 20M/acre

100 12 100 Sweet corn at 13M./acre

155 20 105 Sweet Potato at 30M/acre

140 20 200 Potato at 40M/acre

165 30 225 Tomato at 60M/acre

180 21 280

Averages 148 18 187

Adapted from Knott‟s Handbook for vegetable growers


we harvest potatoes we leave the leaves, when we harvest peppers we leave the whole plant. Generally speaking, the roots tie up a lot of phosphorus, the stems and leaves tie up a lot of potassium while phosphorus is removed from the field when we harvest the seed. Applications of minerals and organic matter can:

Reduce the incidence of deficiencies

Provide conditions for optimum plant development and increase plant health

Improve structural and biological fertility

Enhance the nutritional value of crops

The assessment of the need for mineral or organic fertilizer is based on three factors:

The soil test (chemical analysis)

The observation of an excess or deficit of particular nutrients in our crops

The experience of the farmer

It is important to do annual testing of your soils to make sure the right amount of macro and trace

minerals are available to the crops. When crops show deficiencies we make a distinction between an absolute or sometimes called primary lack of nutrients or a conditional or sometimes called secondary lack of nutrients. In the second situation the nutrients are in the soil but are not available due to a low pH, poor soil structure, drainage et cetera.

A soil test will give

some indication of the state of your soil. But besides giving accurate numbers for its pH and OM, It does not give a good prediction of what yields to expect in an organic system. I have seen many instances where good soil health (good structure, good biological diversity, and good physical qualities) are the overriding factors regarding yield.

Organic farmers have to

realize that they depend greatly on the breakdown of organic matter for plant nutrition. Minerals in compost are tied up and their presence shows only partly up in a soil test. But over time those minerals will be released by virtue of mineralization. Organic farmers rely on improved soil structure to increase the yield of their crops. They need to learn to take lab test recommendations with a grain of salt and the decision to add amendments should be based on a combination of soil tests and field observations coupled with his or her experience as a farmer.

FERTILIZER RATES FOR VEGETABLES IN NEW YORK (Cornell Cooperative Extension 1994)

Nitrogen Phosphorus Potassium

Beans 30-40 0-160 0-80

Beets 150-175 0-100 50-400

Broccoli 120-150 0-200 0-200

Brussels Sprouts 120-150 0-160 0-200

Cabbage 120-150 0-160 0-200

Carrot 120-150 0-160 0-200

Cauliflower 120-150 0-160 0-200

Celery 180 0-200 60-300

Cucumber 120-140 0-160 0-160

Eggplant 130 0-200 0-200

Endive 100-130 0-160 0-200

Lettuce 100-130 0-160 0-200

Muskmelon 120-140 0-160 0-160

Onion 100-110 0-200 0-200

Parsnip 120-150 0-160 0-160

Pea 40-50 0-120 0-160

Pepper 130 0-200 0-200

Potato 150 120-300 50-300

Pumpkin 120-140 0-160 0-160

Radish 60 0-125 0-200

Rhubarb 50-80 0-160 0-200

Rutabaga 130 0-125 0-200

Spinach 130 50-170 0-200

Squash Summer 120-140 0-160 0-160

Squash Winter 120-140 0-160 0-160

Sweet corn 120-140 0-160 0-160

Tomato 130 0-200 0-240

Turnip 130 0-125 0-200

Watermelon 120-140 0-160 0-160


Cation Exchange Capacity: The classic theory is that minerals can only be absorbed by plants when they are in solution of

water. There is sufficient evidence that plant roots absorb organic molecules. I do not have sufficient information on the latter and the following is based on the following hypothesis: Dissolved minerals fall apart in two electrically charged components called 1) basic cations, like hydrogen (H

+1), ammonia (NH4

+1), calcium (Ca

+2), magnesium (Mg

+2),

potassium (K+1

) but also sodium (Na+1

). 2) acidic cations also called anions), like, nitrate (NO3

-), phosphoric acid (H2PO4-), sulfate (SO4

-2), but also aluminum Al3

- and chlorine (Cl-). Potassium, calcium, and magnesium in solution have a positive charge, while nitrate, aluminum, sulfate, chlorine and phosphorus have a negative charge. As minerals are available through the process of osmosis, exchange of ions has to take place. In soluble form Calcium is Ca

+2, a cation

that possesses two positive ions. For the plants to take up calcium, two hydrogen (H+1

) cations need to be released from the plant and replaced for the Ca

+2 cations. When an acidic cation

(anion) like NO3- is absorbed by plants an equal amount of HCO3

- needs to be released.

Respiration of the roots produces carbon dioxide (CO2). Some of the CO2 will form a connection

with water creating hydrogen carbonate (H2CO3). In solution this falls apart in the basic cation hydrogen H

+1 and the acidic cation hydro carbonic acid HCO3

- . As a result the area around the

root contains both the necessary basic cations and acidic cation necessary for mineral uptake for the plants.

Cation exchange capacity (CEC) is a measure of a soil‟s capacity to retain and release nutrients

such as potassium, calcium, magnesium and sodium. Soils with high clay or organic matter tend to have a high CEC value. In order to understand CEC we can imagine the soil particles as having “parking spots” for basic material. Parking spots in this picture are negatively charged allowing a basic material (in this picture “a car”) to be absorbed. Soils high in humus and clay have a negative charge so are able to provide a lot of “parking spaces” for positively charged (basic) cations like calcium, potassium and magnesium. Soil CEC is relatively constant over time although there are reports from growers that were able to dramatically improve the CEC value with a single application of lake weeds at a rate of 60 tons to the acre.

Base saturation is the percentage of the CEC occupied by each of the basic cations (Ca, Mg, Ca,

and K). In other words what percentage of “parking spots” is occupied by what basic material? If calcium has a base saturation value of 70% and magnesium has a base saturation value of 12% then calcium occupies 70% of the total exchange sites (CEC) and magnesium occupies 12% of the total exchange sites (CEC). When plants absorb these minerals a hydrogen ion is released from the roots of the plant occupying the “parking space” for the time being. Root activity tends to raise the pH (potential Hydrogen) in the soil slowly turning the soil more acidic. A hayfield will almost always show a low reading on a pH test which is quickly raised after plowing as broken down organic material releases many basic material like calcium and phosphorus to the soil again.

Soil pH:

Soil pH stands for potential Hydrogen. Liming the soil has created the confusion for some that

the pH is caused by the calcium content of the soil. What matters here is that liming has the positive consequence of removing some of the hydrogen on the available “parking spaces” by replacing them with calcium. Adding gypsum does not change the pH even though it contains a


lot of calcium and this is because the sulfate component of gypsum carries a negative charge.

The need to raise the pH is determined by a soil test.

Drawing after Bemesting en Meststoffen Rinsema et al

The pH value in a soil test indicates whether lime is needed but the soil type will determine how

much lime is needed. The amount of lime to apply is dependent on the reserved soil acidity. This is measured in the lab and indicated by a buffer index. The lower the number of the buffer index

H+

1

H+

1

H+

1

HCO3-

HCO3-

HCO3-

HCO3-

H2O4P-

Ca+2

Ca+2

Mg+22

Mg+22

Na+1

Na+1

Basic cation

Acidic anion

SO4-2

SO4-2

root

Soil particle

Soil particle

NO3-

NO3-

H2O4P-

Mg+22


the more lime is needed. The buffer index is related to the clay and organic matter content and the structure of the soil. Soils high in organic matter or clay will need more lime to raise the pH as they have the ability to store more basic material (calcium, magnesium potassium etc) than a sandy soil low in organic matter. This ability to absorb more basic material reflects in the requirement for more lime to bring the pH up. In order to understand the buffer index we need to go back to our picture of imagining the soil particles having “parking spots” for basic material. Parking spots in this picture are negatively charged allowing a basic material (in this picture “a car”) to be absorbed. Soils high in humus or clay have a lot of “parking spots” available which can be occupied with hydrogen. Raising the pH is like kicking those hydrogen ions out of their “parking spots”. You understand that a soil with a high CEC will need more calcium “cars” to kick the hydrogen “cars” out of the “parking spots.

Each crop has a different optimum pH while this optimum differs for different soil types. Cropland

on a sandy soil performs best at a pH around 6 while this might fluctuate between 5.4 and 7.2 on a clay soil. We aim on our cropland for a pH between 6.3 and 6.8.

Adjusting the pH is important for the following reasons:

1. Root development; a low pH has an impact on the ability of the roots to properly develop 2. Microbial activity is enhanced at more neutral pH levels. 3. Nutrient solubility:

Nitrogen: an acidic soil does not promote microbial activity and therefore less organic matter is converted into ammonia and nitrate through the process of mineralization and nitrification.

Phosphorus is strongly dependent on a correct soil pH. Phosphorus is best available at a nearly neutral pH. The amount of Calcium can have an impact on the availability of Phosphorus as well as Ca tends to release the P ion easier than say Iron or Aluminum that are released at low pH ratings.

Potassium is not affected by the pH

Magnesium is greatly affected by soil pH as low pH can cause leaching of Magnesium esp. on sandy soils

With the exception of molybdenum, micro nutrients are released at a lower pH which could cause the crops to take up too much iron, aluminum, or manganese and create toxicity. A high pH can cause problems as boron, iron, copper and manganese can be tied up.

Plant Minerals: Plants have a certain ability to choose the minerals or acids they take up although this has

certain limitations. Generally a plant will absorb nutrients that are most beneficial but it does not have the ability to exclude certain harmful nutrients. Opposite ions have a positive influence in the uptake of nutrients, while ions with a similar charge limits plant absorption. Here we can speak of ion competition or ion antagonism. An excess of potassium can cause magnesium deficiency, while excessive calcium can cause potassium deficiency. We can help the plants by balancing the available minerals.

A distinction is made between macronutrients and micronutrients. The first group consists of

nitrogen, potassium, phosphorus, magnesium calcium and sulfur as they are taken up in relatively

Ca

+2


large quantities. The second group includes (but is not limited to) zinc, iron, molybdenum, silica, boron, copper, chlorine, cobalt and selenium

Nitrogen (N):

Nitrogen is real dilemma for most organic farmers as deficiencies are the first and foremost

reason for achieving lower yields than our conventional neighbor, while we recognize that liberal applications can create more problems than benefits. Generally speaking excess nitrogen in plants expresses itself in an outbreak of sucking insects like aphids while deficiencies show up in the form of eating damage by beetles. Creating the perfect conditions for plant growth can only be accomplished in high organic matter soils as microbes slowly release the nitrogen through mineralization. For each percent of organic matter we can expect to free up about 20lb of nitrogen per acre through the process of mineralization. Over time this will become unsustainable unless we renew the organic matter. For every 20 lb of nitrogen we will need to replenish about 1600 to 2000 lb of stable organic matter. Clearly this is a very high energy input conversion, so deriving nitrogen from cover crops while practicing reduced tillage is much more efficient.

Nitrogen is brought into the farm by the symbiotic activity of nitrogen fixing bacteria and

legumes. The trick is to keep it in the soil until our cash crops need it. Nitrogen is by nature a gas and therefore elusive. It simply does not like to exist in a mineral form, and it always needs a host to remain part of the solid part of the world. Large amounts of nitrogen can be fixed while little or nothing is left in the soil for our cash crops with poor management practices. Nitrogen gained is easily lost due to leaching, volatilization or erosion.

Nitrogen from cover crops, when plowed under, is released over a very short amount of time

and care should be taken to avoid losses. Deep moldboard plowing wastes most of the nitrogen from a cover-crop as there is little active biological activity below 9 Inches. Most of the nitrogen from cover crops consists of ammonia (highly volatile) which becomes toxic when buried too deep. The nitrogen in manure consists of about half ammonia and the other half in nitrate. In good compost, all ammonia is converted to nitrate. Generally, volatilization and leaching of nitrogen is greatly reduced by good soil structure, proper incorporation, and by crops grown after incorporation that absorb the available nitrogen.

Phosphorus (P):

Phosphorus is an elemental component in the formation of protein. It is an essential element

in the process of reproduction (RNA, DNA), and essential for plant growth. It stimulates growth of young plants, giving them a good and vigorous start and greatly influences the quality of the seed. It has an influence on a variety of physiological processes of the plant like assimilation and respiration.

Phosphorus has a positive influence on root development of all crops which explains some of

the stunting that happens at deficient levels. It enhances maturity of all crops and increases the sugar content, which is important in all of the fruit type vegetable like peppers, tomatoes, squash sweet corn etc. It also enhances tillering of grains and improves quality of straw, increases the number of potatoes per plant and the quality of the starch content. It also improves the stand of a cover crop or hayfield, while poor stands, inundated with weeds, are often an indication of low levels of P.

Phosphorus in organic materials is released on our farm solely by mineralization through the

activity of microorganism. Soil moisture and temperature greatly influence these processes. Deficiency will be visible in the discoloration of the older leaves turn a reddish purple color. In severe cases the plants will be completely stunted. We see phosphorus deficiency each spring in our cole crops as the cold soil has little microbial activity. Most crops in this family


(esp. cauliflower) are highly sensitive to P deficiency. As we have good reserves of P in our soils the discoloration of the leaves disappears once the soil is warmed up.

Generally speaking vegetable crops have a low need for Phosphorus. The average take up

of phosphorus from vegetables out of the soil is only about 20 lb per season. Compost is a source that is usually very high in phosphorus as the grains fed to animals contain high amounts of it while very little is utilized by the animals. States like Maryland recognize the problem of excessive phosphorus leaching out into the ground water from manure applications. Laws have passed that also restrict the amount of compost spread per acre each season.

Potassium (K):

Potassium plays an important role in tissue formation. Its role in the plant is indirect,

meaning that it does not make up any plant part. Instead, it acts as a catalyst regulating enzymatic processes in the plant that are necessary for plant growth.

Potassium is important for a plant's ability to withstand extreme cold and hot temperatures,

drought and pests. Another responsibility in the plant is the regulation of water use. Potassium affects water transport in the plant, maintains cell pressure and regulates the opening and closing of stomata‟s (small openings found on the leaf responsible for cooling and taking in carbon dioxide for photosynthesis).

Symptoms of potassium deficiency include yellowing of the lower leaves and, in severe

cases, leaf-tip dieback. Once symptoms are present, the plant's ability to withstand stress conditions, such as high heat, drought and pests, is diminished.

Only small amounts the potassium in the soil is available to plants as the majority is tied up in

the mineral part of our soils. Through soil activity we are able to make this available to the plants. For every lb of available potassium we can assume to have another 100 lb in reserve tied up in soil particles.

Soil type and environmental conditions have an effect on the amount of potassium available

for plant use. Potassium availability is highest under warm, moist conditions in soils that are well aerated with a neutral or slightly acidic pH. A wet cold spring provides poor conditions for potassium uptake. Excessive calcium or magnesium levels will also affect the uptake of potassium.

Silica (SiO2):

Silicon (Si) is the most abundant element in the soil. Silicon dioxide comprises up to 50

to 70 percent of the soil mass. All plants take up silicic acid as a consequence of silicon dioxide becoming soluble as silicic acid.

Silica is not recognized as an essential element to plant growth but the beneficial effect on

this element on the growth, development, yield and disease resistance have been observed in many different plant species. Silicic acid uptake is much greater by monocotyledons (grains, grasses) than dicotyledons (clovers, most vegetables). It is reported that up to ten percent of the dry matter of rice can be silica. Most research has been on rice where in some cases applications of calcium silicate at 5 ton/ha replaced the need fungicides to control neck and leaf blast (Chad Husby, the Role of Silicon in Plant Susceptibility to Disease,1998). In other studies it is showed that silica acid promotes the formation of nodules in cowpeas (Nelwamondo, Dakora Capetown University 1999). In sugar cane silica helps increase the sugar content (numerous studies


1980), while in sorghum it helps the plant to develop greater resistance to drought (numerous

studies 1980) or anthracnose (Viçosa Federal University, 2009). Silica is also essential in the nutrition of animals in regulating bone calcification and its structural role in connective tissues. Nevertheless most of the silica is excreted so the manure contains high amount of silica. As silica has the ability to lower aluminum levels in our brain, it has been reported to lower the incidence of Alzheimer‟s.

The application of soluble fertilizer has a large impact on the uptake of plants of silica

therefore indirectly causing a higher incidence of plant diseases. Silicon, the element, occurs in nature as silicon dioxide (SiO2), often called silica, and an enormous variety of silicates. Now, plants absorb their silicon from the soil after it is in a soluble form; it's then converted into silica-containing fibers for their structural support. Plants differ in their ability to absorb Si from the soil solution. Marschner, (Mineral Nutrition of Higher Plants. Academic Press, London 1995) identifies three types of plants based on their capacity for Si absorption: Silicon accumulators include several primitive plants including the horsetails

(Equisetum) and wetland grasses such as paddy rice that contain Si at 5 percent to 10 percent of their leaf dry weight. This requires an active Si uptake by the roots.

Si non-accumulators contain .5 percent to 1.5 percent Si in their dry leaf tissues and include most grasses and cereal grain but also potatoes and turnips. At those levels silica with its abrasive nature can wear out a few pair of jeans in a season by a person that handles a lot of hay or straw, while potatoes are an excellent source for silica.

The Si excluders contain less than .23 percent Si in their dry leaf tissues. But even at .25 percent to .1 percent of dry tissues, Si is present at levels comparable to sulfur, phosphorus and magnesium.

Calcium (Ca):

Calcium is very different from Silica. It behaves very differently in the soil. Sometimes it is

helpful to create a picture we can relate to in order to grasp the nature of the object we are describing. Some people have described silica to a monk in a spotless white robe; a substance that is part of this world but tends to be uninvolved while it communicates with the gods. If we want to create a mental picture of calcium Popeye after eating some spinach comes to my mind; it behaves reactionary, its intent is to better the world through action. This quality becomes evident when we deal with burnt lime. Burnt lime is made by roasting crushed limestone in a kiln to drive off carbon dioxide (CO2). This changes the chemical form of the limestone from a carbonate to an oxide, leaving a material that is highly concentrated in calcium oxide or calcium and magnesium oxide. Burnt lime is very unpleasant to handle as it will burn they eyes, skin or lungs when we are exposed to the dust. Burnt lime has a strong reactivity with moisture in the air. When people apply burnt lime (as it raises the pH very rapidly) great care has to be taken as it tends to clump up on wet soil, and burn the plants. Calcium as a being in this world has tied up most of the carbon dioxide. 75% of this gas is tied up by sea shells and lime deposits. In this form calcium has lost its nature of being Popeye as it is tied down by the carbon. Calcium carbonate is not very soluble and as farmers we are aware of this as it will take up to a full season before the lime we spread will affect the pH. Once in solution though it acts like Popeye again throwing all the hydrogen ions of their “parking spots”.

Calcium when available in large amounts can tie up nutrients. Calcium rich soils have

problems with nutrient availability so it goes as with everything else, “too much of a good thing” can be a problem.


Sources of minerals from the OMRI list are:

Nitrogen: N fixation by legumes, compost, animal by-products (blood meal and fish fertilizer),

plant by-products (cotton meal, alfalfa meal, soybean meal, apple, and fermentation wastes), mined sodium nitrate (Na NO3) (16-0-0) (should not exceed 20% of the total nitrogen need of the crop).

Phosphorus: Compost (esp chicken), rock phosphate, animal by-products (bone meal; fish,

shrimp, & oyster scraps; leather)

Potassium: Compost, plant by-products (ash, dried seaweed), greensand, SulPoMag

(K2SO4•2MgSO4) (0-0-20-14), sulfate of potash (K2S O4) (0-0-50),

Magnesium: Dolomitic lime, Epsom salts (MgSO4), sulfate of potash magnesium, bone meal,

plant by-products (cottonseed meal, wood ash) Calcium: chicken compost from layers, high calcium lime, gypsum (CaSO4), bone meal, ash

Sulfur: compost, plant by-products (cotton motes, peanut meal), elemental sulfur, gypsum

(CaSO4), Epsom salt (MgSO4), sulfate of potash (K2SO4) (0-0-50)

Boron: Solubor (17½% boron) (each quart weighs about 1½ lb and adds about ¼ lb of boron to

the acre. Borax (11 % boron) (Na2B4O7·10H2O) Zn (Zinc): Zinc Cypress (10% zinc soluble)

DIFFERENT COMPOSITIONS OF SEVERAL ORGANIC FERTILIZERS

All quantities in lbs./ton, except the first column

type of manure

lbs./ dry org. N P K Ca

180days matter matter

dairy-cow

solid 13,000 430 280 11 7.6 8 8

urine 9,000 52 20 8 0.4 16 0.2

slurry 22,000 190 120 9 4 10 4

pig

solid 770 460 320 15 18 7 1.8

urine 990 40 10 13 1.8 9 1.2

slurry 1760 160 126 14 9 8 1.5

chicken

solid 44 640 460 25 37 18 47

slurry 88 220 160 16 13 10 22

with bedding, 1,160 700 32 40 22 57

horse 620 500 10 6 11 6

Note: It is fair to say that vegetables -in their particular requirements of high potassium and nitrogen but lower needs for phosphorus- do best with compost made with out of hay-fed cow or horse manure. Above numbers are from lactating cows fed generous amounts of grain (which creates a relative high P number)

Adapted from: Bemesting en Meststoffen by ir. W.T. Rinsema

Fertility Management at Roxbury Farm - Small Farm Central Control

Documents

Transcript of Fertility Management at Roxbury Farm - Small Farm Central Control