Sensible Soil Health

Andrew McGuire

Brandon, Manitoba, Jan. 30, -40

Potato Yields:Washington 33 tons/acre Idaho 27Nebraska 21Wisconsin 20Maine 15

Average of 123 soils:

11

Seattle

•Climate/temperature•Precipitation/water

•Nutrient management•Pest Management

Soil Health

Importance of soil health

Rainfed,dry

Rainfed,humid

Irrigated

Index of Climate+Soil Productivity

IrrigatedSo

ybea

n Yi

elds

Egli

and

Hatf

ield

201

4

“…because MANAGEMENT and WEATHERare integral factors, no meaningful correlation between texture, bulk density, or structureand crop productivity is possible.”

Letey 1985

Bulk density + structure ≈ soil health

Manage the problem

What problems do you have with your soils?

Modified from Caley Gasch, NDSU

Photo: USDA

Doctors: First, Do No Harm

Farmers:

First, Control Erosion

Videos on YouTube

Concentrate SOM at soil surface, top 1-3”

Organic matter distributed uniformly to depth of tillage

Organic matter concentration at soil surface

Benefits• Water and nutrient storage• Soil C sequestration with

perennials

Benefits• Increased infiltration of water and air• Resists wind and water erosion• Resists crusting• Enhances biological activity• Allows seedings to emerge

unhindered

Import converted sunlight in BULK

•Manure•Compost•Quickest way to increase soil organic matter.

It takes BULK material to change the BULK soil

Add TONS, not gallons or quarts to improve overall soil.

Beware the Bio-products

• Bio Secure• Bio Safe• Bio Innovator• Bio Flora• Bio Generator• Byo Soil• Byo Gon• Bio Forge• Bio Terra Plus• BioBurst

Exceptions?Applying a specific material, for a specific purpose, at a specific location in the soil.

Ecological Theory vs. AgricultureAre Cover Crop Mixtures the Answer?

Ecological hypothesis: more diversity is better.

+Biodiversity

+Productivity

Synergistic effects: Complementarity, Facilitation, etc.

Cover Crops, Best Mixtures vs. Best Monocultures

Flor

ence

and

McG

uire

202

0

Monoculture better Mixture better

Practices that help MAXIMIZE Photosynthesis:

Practices that Help minimize tillage, (descending order of effectiveness):

Relay crops No-till/Direct seedingCover crops Strip-tillPerennial crops Vertical tillageOverwintering crops and cover crops Non-inversion tillageManure/compost, imported photosynthesis

Practices that facilitate the above practices: Practices that facilitate the above practices:Livestock grazingCrop rotationNutrient and Pest managementIrrigationNo-till, strip-till, practices that reduce field prep time between crops

Livestock grazingCrop rotationResidue managementWeed management

Two Principles, Many Practices

Sensible Soil Health• Don’t exaggerate what soil health can do for you.

• Identify the problem• Manage the problem

• MAXIMIZE photosynthesis• Minimize tillage

• Email: andrew.mcguire@wsu.edu• Twitter: @agronomistag• Blog at: https://bit.ly/32Iyq2k

Sensible Soil HealthBrandon, Manitoba, Jan. 30, -40Slide Number 3Slide Number 4Slide Number 5Slide Number 6Slide Number 7Slide Number 8Slide Number 9Slide Number 10Slide Number 11Slide Number 12Slide Number 13Slide Number 14“…because MANAGEMENT and WEATHER �are integral factors, �no meaningful correlation between �texture, bulk density, or structure �and crop productivity is possible.”Manage �the problemWhat problems �do you have with your soils?Slide Number 18Slide Number 19Slide Number 20Slide Number 21Doctors: First, Do No Harm��Farmers: �First, Control ErosionSlide Number 23Slide Number 24Slide Number 25Slide Number 26Slide Number 27Slide Number 28Slide Number 29Slide Number 30Slide Number 31Slide Number 32Slide Number 33Slide Number 34Slide Number 35Slide Number 36Concentrate SOM at soil surface, top 1-3”Slide Number 38Import converted sunlight in BULKIt takes BULK material to change the BULK soilBeware the Bio-productsSlide Number 42Exceptions?Slide Number 44Slide Number 45Slide Number 46Slide Number 47Ecological Theory vs. Agriculture�Are Cover Crop Mixtures the Answer?Slide Number 49Ecological hypothesis: more diversity is better.Cover Crops, Best Mixtures vs. Best MonoculturesFlorence and McGuire 2020Slide Number 53Slide Number 54Slide Number 55Slide Number 56Two Principles, Many PracticesSensible Soil HealthSlide Number 59Slide Number 60