Nitrogen and Potassium Utilization in Almond Orchards

F.J.A. NiederholzerUC ANR CE Farm Advisor, Colusa/Sutter/Yuba Counties

February 7th, 2017

This talk will cover the following topics.

Annual N Treatme

nt(N/acre)

2008Kernel yield

(lb/acre)

2009Kernel yield

(lb/acre)

2010Kernel yield

(lb/acre)

2011Kernel yield

(lb/acre)125 lb 3,506 a 2,715 a 2,849 a 3,811 a

200 lb 3,534 a 2,943 ab 3,413 b 4,274 b

275 lb 3,732 a 3,183 b 3,734 bc 4,643 c

350 lb 3,733 a 3,489 b 4,030 c 4,735 c

Why N & K matters in almond production

N & K in the soil and trees

Effective, efficient and safe N & K management

Annual N Treatment(N/acre)

2008Kernel yield

(lb/acre)

2009Kernel yield

(lb/acre)

2010Kernel yield

(lb/acre)

2011Kernel yield

(lb/acre)

125 lb 3,506 a 2,715 a 2,849 a 3,811 a

200 lb 3,534 a 2,943 ab 3,413 b 4,274 b

275 lb 3,732 a 3,183 b 3,734 bc 4,643 c

350 lb 3,733 a 3,489 b 4,030 c 4,735 c

Within a year of changes in N fertilizer treatments, yield differences can appear.

15.3 28.9 30.2ROI

P. Brown, U

C Davis

Nutrient Nutrient removed in 1000 lb kernel crop

Nutrient/acre removed in average crop

Potassium 80.0 lbs 195.2 lbsNitrogen 68.0 lbs 165.9 lbsPhosphorus 8.96 lbs 21.86 lbs

Calcium 6.68 lbs 16.30 lbsMagnesium 4.64 lbs 11.32 lbs

Sulfur 2.62 lbs 6.39 lbsBoron 0.31 lbs 0.76 lbsIron 0.19 lbs 0.46 lbsZinc 1.12 oz 2.72 oz

Manganese 0.68 oz 1.66 ozCopper 0.34 oz 0.83 oz

P. Brown, U

C Davis

Nitrate concentrations in many CA wells exceed drinking water standards

Red dots represent wells that exceed the drinking water standards.

Excessive orchard N risks increasing hull rot and yield loss.

Treatment(K2O/acre/

year)

1998 Kernel yield

(lb/acre)

1999 Kernel yield

(lb/acre)

2000 Kernel yield

(lb/acre)

ROI(income$:

fertK$)

0 lb 780 a 3930 a 2410 a240 lb 890 a 3840 a 2860 b600 lb 830 a 4380 a 2860 b960 lb 1070 a 4020 a 2770 b

Reidel, Weinbaum, Brown and Duncan, UC Davis

Potassium fertilization provides a return on investment, especially after heavy crop year.

6.12.41.2

The NITROGEN CYCLE in soils.

Singer and Munns, Soils: An Introduction. 2002, page 173

Singer and Munns, Soils: An Introduction. 2002, page 229

Potassium Cycle in soil.

Potassium and nitrogen reach roots by two processes: mass flow and diffusion. Generally, N is more soil mobile than K.

Nutrient Root interception Mass Flow Diffusion

Nitrogen 1 99 0

Potassium 2 20 78At the root surface, plants expend energy to absorb the nutrients.

In the tree, potassium is a chemical activator/regulator, while nitrogen is a essential ingredient of proteins, etc.

Nitrogen Potassium

Function

Essentialingredient in molecules in

plant

Helps regulate essential

processes and transport within

the plant Feedback

mechanism limiting uptake?

Yes No (luxury consumption)

The timing of greatest need for available N is March to June, when the crop is growing.

P. Brown, UC Davis

2011 2012

P. Brown, UC Davis

The amount of N (and K) needed during March to June is driven by cropload.

Same orchard. 2012 orchard N use is 200 lbsN/acre LESS than 2011 due to very light ’12 crop.

Almond nut K & N accumulation patterns differ during a growing season.

Lb N per 1000 lb crop Lb K per 1000 lb crop

Days after full bloom Days after full bloom

Nitrogen storage in woody tissue = ̴40 lbs N/acrePotassium storage in woody tissue = ̴25 lbs K/acre

P. Brown, UC Davis

Traditional orchard fertility test (leaf analysis) are a good indication of deficient, but not excessive nutrients.

P. Brown, UC Davis

• Right Rate• Right Time

• Right Location

• Right Material

The 4 R’s of Fertilizer management are the guiding strategy for all nutrients & especially Nitrogen and Potassium.

• Right Rate

•Right Time• Right Location

• Right Material

The 4 R’s of Fertilizer management are the guiding strategy for all nutrients & especially Nitrogen and Potassium.

1. Use yield history to estimate annual budget. Ante up: apply 20% of annual budget by mid-March.

Application Timing % of total budgetLb. N per

application if it’s a normal crop

Bloom-leaf out (Feb-Mar) 20% 47

April 30%

May/June 30%Hull split to postharvest 20%

Experience & spring leaf test results helps decide N & K inputs after first 20% of annual N budget is applied.

In season, use spring leaf levels (N) to revise fertilizer program on the go.

• UC ESP (Early season Protocol) – 43 days (± 6 d.) after full bloom– Take all leaves of 2-3 non-bearing spurs around the tree– Sample trees at least 90’ feet apart– Request full nutrient analysis from lab– Plug results into UC model in Excel.– Find the model at:http://ucanr.edu/sites/scri/Crop_Nutrient_Status_and_Demand__Patrick_Brown/orhttps://www.sustainablealmondgrowing.org/

2. Use experience, bloom weather & spring leaf N levels to decide on April-June rates (30% & 30% of total if all appears “normal”).

Application Timing % of total budget Lb. N per application if it’s a normal crop

Bloom-leaf out (Feb-Mar) 20% 47

April 30% 71May/June 30% 71

Hull split to postharvest

3. Use actual cropload and summer leaf N analysis to determine how much, if any, postharvest N to apply.

Application Timing % of total budget Lb. N per application if it’s a normal crop

Bloom-leaf out (Feb-Mar) 20% 47

April 30% 71May/June 30% 71

Hull split to postharvest 20% 47?

An example of differences in yields and N use in the same orchard. Nickels pruning trial. 2015.

Variety Yield/acre N use/acre*

Nonpareil 2,947 200Monterey 2,586 176

Aldrich 2,468 168Carmel 2,225 151

*Assumes 68 lbs N/1000 lbs crop for all varieties

Irrigation systems can be designed to treat varieties separately.

Potassium timing and rates are similar to nitrogen for the same cropload.

Application Timing % of total budget Lb. K2O per application if it’s a normal crop

Bloom-leaf out (Feb-Mar) 20% 46

April 30% 70June 30% 70

Hull split to postharvest 20% 46

Summer leaf levels are a report card for preharvest fertility & key planning input(s) for postharvest fertility program.

Critical July leaf nutrient concentration (%)

Old target New targetNitrogen 2-2.5 2.4-2.5

Potassium >1.4 1.0

• Right Rate

• Right Time

•Right Location• Right Material

The 4 R’s of Fertilizer management are the guiding strategy for all nutrients & especially Nitrogen and Potassium.

Right Place: Irrigation Rapidly Moves N into SoilSurface applied N Followed by Irrigation (90 minutes)

Broadbent, 1958, graph from www.IPNI.org

In season, use K deficiency leaf symptoms (or early leaf sampling from private lab) to revise fertilizer program on the go.

Soil CEC (soil K storage potential) influences K input plans & practices.

Practice High CEC Soil (>15 meq/100 g of soil)

Low CEC soil (<15 meq/100g of soil)

Dormant Soil Applications Yes – can be “slugged” on Yes – but only partial

budgetBanding gypsum to

move potassium Yes, if heavy clay NOIn-Season

Applications Yes, if needed Yes- 40-60% of the budget

Fertigation of K Yes Yes – be cautious of large applications

No benefit from applying more than 240 lbs K2O/acre/year has been measured in short (< 5 years) UC trials.

Right timing, location, & rate are vital to effective, efficient & safe N & K fertilization. Material is less critical.

Nitrogen PotassiumAnnual Rate* 68 lbs N 80 lbs K

(96 lbs K2O)

Timing Mar-early June; Sept.20-30-30-20 Mar-June; Sept.

Location Tree row, upper 0-2’ root zone

Tree row, upper 0-2’ root zone

Material Grower choice Grower choice

*per 1000 lbs kernel crop (includes hull, shell and kernel). Adjust annual rate for the current year based on cropload and tissue tests

Thank you