PowerPoint Presentation

Cover Crops, Compost, and No-Till: A Formula for Soil HealthTim ReinbottBradford Research CenterCollege of Food and Natural Resources

Mother in Law-Her First Garden Was Her Best Garden

What Was Her Garden Before It Was A Garden?

What Happened? Plowed Up Planted Into a Vegetable Garden-6 months a year

Lets Take A Look At What Might Have Happened To The Soil

What Happens When You Till? Destroys Organic Matter? Loss of Organic MatterSoil structureSoil microbial biomassRelease of CO2

Soil Erosion

Why Till?Weed Control

Organic Matter

This is what separates us (Missouri) from Central Iowa, Illinois, Minnesota, Indiana, etcIn these areas climatic conditions favor the accumulation of Organic MatterSlower breakdown, long history of deep rooted native perennial plants

What is Soil Organic Matter?SOM is derived fromPlant residue (both litter and roots)Animal remains and excretaLiving soil microbes (microbial biomass)Over time fresh organic material is transformed into soil organic matter

Crop ResiduesBacteriaFungiActinobacteriaSOM8

8Soil organic matter is all the material in soil that is made up of carbon (not including the carbon is in limestone or that is present as carbonates or bicarbonates).So, soil organic matter is all dead plant material, both above ground litter and roots, and all animal remains and excreta. Most scientists also include living soil microorganisms as part of the soil organic matter.These fresh organic materials have none of the properties of soil organic matter that we just mentioned. But over time they are decomposed by soil microbes and gradually turned into soil organic matter.

Loss of Organic Matter and Loss of Soil Structure

Agriculture and SOM20 40% of SOM is lost on cultivationManagement effects on SOMTillage (disturbance) Chemical Fertilization Manure Residue Retention Crop Crop Rotation Cover Crop

10Decline in SOC from Sanborn Field Plots showing increase following the return of residues beginning in 1950

What Also Does Tillage and Loss of Organic Matter Affect?Soil Micro Organisms

Soil Life (macro)

Help create soil structure and break down larger plant residuesEarthwormsNematodesBeetlesAntsTermitesSpringtails

One tablespoon of soil has approximately 1 billion soil microbes:Bacteria: 3,000,000 to 500,000,000Actinobacteria: 1,000,000 to 20,000,000Fungi: 5,000 to 1,000,000Yeast: 1,000 to 1,000,000Protozoa: 1,000 to 500,000Algae: 1,000 to 500,000Nematodes: 10 to 5,000Soil Life (micro)

Soil microbe counting exercise: count as high as you can for 30 sec (usually about 150). Calculate how long it would take to count to 1 billion. Usually equates to about 6 years and 4 months.13

The soil microbes in the plow layer has the mass equivalent of two cows (2400 lbs) per acre that need to be fed Soil organisms are much like cows, they need inputs of plant residues for food and energy

Specifically, they need the carbon that is contained in plant residue and soil organic matter

Were Are These Soil Micros? The Decay Zone: Top 0-6 inches in the Soil

What Else Feeds Soil Micros?Manures

Compost

What If We Could Make Compost Out Of the Food Waste From Campus?

Food Waste+Horse BeddingGetting The Right C: N Ratio (or Greens to Brown)

Using a Large Mixer

Lots of Ways To Compost

Temperature Is Important In Composting. We Want to Achieve 140-150 degrees F

Oxygen Is Critical. Aerobic vs Anaerobic AerobicEarthy Smell-much of the nutrients are kept in the compost and not released

AnaerobicAcidic smell-release of methane and Nitrous Oxide

Finished Product

We Know That Tillage Hurts Soil Micros Through Reducing Soil Organic Matter, Compost and Manures Help, What Else?

Living Plant Roots Exudates Feeds The Bacteria, Fungi, and other Life-40% of Carbon Fixed By The Leaves Is Exuded By the Roots

Also The Root Turnover Feeds The Soil Micro Organisms26

SOM is NOT just from crop residues! Plant roots are very important to SOM production. Living plants (i.e, cover crops) help retain and PRODUCE SOM.26

Our Goal Is To Have Something Living on the Soil Year Around and For There To Be Diversity

What Are Cover Crops?

BuckwheatCrimson CloverOats

Establish In the Fall After Harvest-Grain Crops or Vegetables

Overwinter and Then Grow In the Spring: Hairy Vetch-in Mid MO

Early MayLate May

Polycultures-Grasses, Legumes, Forbs-Why? More Diversity!

Can Be Planted in the Summer For Vegetables and Wildlife

Cover Crops Between MelonsCompetition Reducing Weeds

Sorghum x Sudan In Between Rows of Tomatoes-Can Help Control Weeds

Sorghum X Sudan Can Be Mowed Back and It Will Regrow. Returning Biomass (Shoot and Root) To The Soil

Sorghum x Sudan In Between Rows of Tomatoes-Can Help Control Weeds

What Do I Now Do On My Garden? Cover Crops -Oats and Legumes

Lets Put It All Together

100+ Years of Tillage Has Severely Reduced Soil Organic Matter and Soil Micro Organisms

Tilled vs No-Till-We Have Destroyed Much of Our Soil StructureLong Term PastureTilled in a Corn/Soybean/Wheat Rotation

All organic matter in soil is not equalScientists describe 3 pools of soil organic matter **really is a continuum of decomposition41Passive SOM500 5000 yrsC/N ratio 7 10

Active SOM1 2 yrsC/N ratio 15 30

Slow SOM15 100 yrsC/N ratio 10 25

Recently deposited organic materialRapid decomposition10 20% of SOMIntermediate age organic materialSlow decomposition10 20% of SOMVery stable organic materialExtremely slow decomposition60 80% of SOM

CO2Organic Material

41Soil organic matter (SOM) is composed of the living (microorganisms) not considered part of SOM by most scientists, though, the dead (fresh residues, active C), the really dead intermediate fraction = slow fraction, and the really, really dead (humus) fraction = passive.

Results are read in a spectrometer in lab or field or from a color card

Potassium Permanganate Test

KMnO4 oxidizes active carbon. The purple color of the chemical changes to pink the more active carbon there is in a soil sample.

Active Carbon in Soil Organic Matter-The Lighter the Color the MORE Active Carbon

Active Carbon-More In Permanent Polycultures-Cover Crops More Than No-Till

Does More Diversity And Active Carbon Result in More Soil Micros?

What Has Most Abundant and Diverse Soil Microbes?

No-Till With Cover CropsNo-Till In A Corn/Soybean Rotation

Tilled Each Year in a Corn/Soybean Rotation

What Has Most Abundant and Diverse Soil Microbes?

FencerowNative Warm Season Grass

Cool Season Grass Mix

Restored Native Prairie

One Last Concept-Microbes and Organic Matter Hold The Soil Together Like Glue

Better Aggregate Stability Results In More Water Infiltration and Less Water and Soil RunoffTilledNo-TillNo-Till w/ Cover Crops

Video

So Why Was My Mother In-laws First Garden Her Best?Healthier Soil!

What Could She Have Done?

Questions? Comments?Tim Reinbott884-7945Bradford.cafnr.org