USDA promotes agroecological practices though soil education for farmers & ranchers

July 22, 2015

Phrase from F. M. Lappe trying to summarize the message: “Keep it covered. Keep it diverse. Keep it growing.”
Inspired by: United States Department of Agriculture Natural Resources Conservation Service, “unlock your farm’s potential: discover the cover,” September 2012, Accessed on April 25, 2014, http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1049063.pdf

 

“Tillage can destroy soil organic matter and structure along with the habitat that soil organisms need. Tillage, especially during warmer months, reduces water infiltration, increases runoff and can make the soil less productive. Tillage disrupts the soil’s natural biological cycles, damages the structure of the soil, and makes soil more susceptible to erosion.”
Source: United States Department of Agriculture Natural Resources Conservation Service, “unlock your farm’s potential: do not disturb,” September 2012, Accessed on April 25, 2014, http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1049424.pdf

 

“Healthy soil has a sweet and earthy aroma. This is the scent of geosmin, a byproduct of soil microbes called actinomycetes. These microbes decompose the tough plant and animal residues in and on the soil and bring nitrogen from the air into the soil to feed plants”
“Healthy soil is easy to dig into. It is soft, moist, and crumbly, and allows plants to grow their roots more freely and unimpeded”
Source: United States Department of Agriculture Natural Resources Conservation Service, “unlock your farm’s potential: dig a little learn a lot,” September 2012, Accessed on April 25, 2014, Source: United States Department of Agriculture Natural Resources Conservation Service, “unlock your farm’s potential: dig a little learn a lot,” September 2012, Accessed on April 25, 2014, http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1049062.pdf

 

“Highly aggregated soils—those granular, durable, distinct aggregates in the topsoil that leave large pore spaces between them—are soils with good tilth and good structure”
“Earthworms, for instance, produce both new aggregates and pores. Their binding agents are responsible for the formation of water-stable, macro-aggregates, and their burrowing creates continuous pores linking surface to surface soil layers. As they feed, earthworms also speed plant residue and decomposition, nutrient cycling, and redistribution of nutrients in the soil profile”
Source: United States Department of Agriculture Natural Resources Conservation Service, “Healthy soils are: well-structured,” Accessed on April 25, 2014, http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1193171.pdf

 

“Estimates vary, but if you could weigh all the organisms in the top six inches of soil on an acre of land, you’d find they would weigh between 2,500 pounds to more than 5,000 pounds, depending on how healthy the soil is. That is a LOT of life”
“there are more soil microorganisms (microbes for short) in a teaspoonful of soil than there are people on the earth”
“These microbes, which make up only one-half of one percent of the total soil mass, are the yeasts, algae, protozoa, bacteria, nematodes, and fungi that process soil into rich, dark, stable humus”
Source: United States Department of Agriculture Natural Resources Conservation Service, “Healthy soils are: full of life,” Accessed on April 25, 2014, http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1193147.pdf

 

“When you have a vegetative cover on the soil, especially a living cover, you offer those microbes both food and shelter. Some scientists say when you till the soil and remove crop residues, the effects are as devastating to soil microbes as a combination of an earthquake, hurricane, tornado, and forest fire would be to humans”
“Because living roots provide the easiest source of food for soil microbes, growing perennial crops or long-season cover crops is the key to feeding the foundational species of the soil food web—so they’ll be healthy and ready to perform throughout the primary growing season”
Source: Source: United States Department of Agriculture Natural Resources Conservation Service, “Healthy soils are: Covered all the Time,” Accessed on April 25, 2014, http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/health/?c...

 

“Only half the original organic matter remains in most modern cultivated soils. In general, organic matter levels have fallen from 5-6 percent of the soil to less than 3 percent on most cropland soils”
“Using tillage depletes organic matter. Each time the soil is tilled, oxygen is stirred into it, stimulating microbial action to decompose organic matter at an accelerated rate. As a matter of fact, when a woodland is cleared and planted or a prairie is plowed, most of the organic matter that was built over hundreds of years is lost within 10 years of tillage”
“The carbon in organic matter is the main source of energy for the all-important soil microbes and is also the key for making nutrients available to plants”
“Compost in particular breaks down more slowly and improves soil structure more quickly than other organic materials. Manure breaks down quickly to add nutrients for crops, but it takes longer to improve the soil than compost”
“ “Stabilized organic matter” or humus, acts like a sponge and can absorb six times its weight in water. It’s also a reservoir for nutrient storage, sequestering carbon from the atmosphere and other sources”
Paraphrased from graphic: Stabilized organic matter is 1/3 to ½ of all organic matter, takes a century or more to decompose, and has exceptional water holding capacity and soil structure benefits, and acts as a reservoir for nutrients, including carbon”
Source: United States Department of Agriculture Natural Resources Conservation Service, “Healthy soils are: high in organic matter,” Accessed on April 25, 2014, http://nrcspad.sc.egov.usda.gov/DistributionCenter/pdf.aspx?productID=1024

 

“Organic matter builds as tillage declines and plants and residue cover the soil. Organic matter holds 18-20 times its weight in water and recycles nutrient for plants to use”
“One percent of organic matter in the top six inches of soil would hold approximately 27,000 gallons of water per acre”
“Most farmers can increase their soil organic matter in three to 10 years if they are motivated about adopting conservation practices to achieve this goal”
Source: United States Department of Agriculture Natural Resources Conservation Service, “Soil Health: Key Points,” February 2013, Accessed on April 25, 2014, http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1082147.pdf

 

“One of the most beneficial soil health properties is that of soil organic matter (SOM). A typical acre of soil 6 inches in depth weighs about 1,000 tons. One percent organic matter equates to 10 tons of organic material”
“Since it takes at least 10 pounds of residue to decompose to 1 pound of organic material, SOM levels under the right management conditions will increase at a very slow rate. Studies have shown that for every percent increase in SOM, and additional 16,500 gallons of water is available in the soil. Using the same commodity prices to estimate water infiltration, this would equate to an additional $13 per acre income, per percent increase in organic matter”
Source: United States Department of Agriculture Natural Resources Conservation Service, “Value of Soil Health,” April 2013, Accessed on April 25, 2014, http://www.nrcs.usda.gov/wps/portal/nrcs/main/sd/newsroom/factsheets/

 

“Soil organic matter is that fraction of the soil composed of anything that once lived”
“Well-decomposed organic matter forms humus, a dark brown, porous, spongy material that has a pleasant, earthy smell. In most soils, the organic matter accounts for less than about 5% of the volume”
“The amount of organic matter lost after clearing a wooded area or tilling native grassland varies according to the kind of soil, but most organic matter is lost within the first 10 years”
Source: United States Department of Agriculture Natural Resources Conservation Service, “Soil Quality Indicators: Organic Matter,” April 1996, Accessed on April 25, 2014, http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_053150.pdf

 

“Reducing or eliminating tillage (or plowing) not only improves soil health but can save energy. In fact, at 2012 prices, a 50-percent reduction in fuel costs at $4/gallon would come to a $10,000 annual savings on the average 1,200-acre farm. In addition, after 5 years of no-till, nitrogen cycling is so enhanced that North Dakota State University recommends 50 pounds per acre per year less applied nitrogen in that system” (Calendar page: April 2014)
“The blanket of mulch provided by the cover crop residue not only lowers soil temperatures, which protects soil microorganisms, but it also reduces the amount of water lost through evaporation and protects the soil from erosion” (Calendar page: September 2014)
Source: United States Department of Agriculture Natural Resources Conservation Service, “2014 Soil Planner,” Accessed on April 25, 2014, https://nrcspad.sc.egov.usda.gov/distributioncenter/pdf.aspx?productID=1019

 

In the links below are great learning tools for farmers from USDA promoting many agroecological practices, says FL Lappe 4.14

 

Website for “Unlock the Secrets in the Soil” campaign: http://www.nrcs.usda.gov/wps/portal/nrcs/main/national/soils/health/
Website for healthy soil factsheets (including “Soil Health Matters”, “Soil Health Nuggets”, and “Healthy Soils are… Full of Life, High in Organic Matter, Covered All the Time, and Well Structured” factsheets): http://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/national/soils/healt...
Website for cover crop plant guides: http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/health/?c...
Website for soil health infographics: http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/health/?c...
Website for “Healthy Soils are…” newsletter articles: http://www.nrcs.usda.gov/wps/portal/nrcs/detailfull/national/soils/healt...
Resources on the Science of Soil Health: http://www.nrcs.usda.gov/wps/portal/nrcs/main/soils/health/resource/

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