Kevin Brown, Former NRCS Tennessee State Conservationist, Gardening to Improve Soil Health
Conservation partners reading this newsroom article are no strangers to Kevin Brown. Kevin, recently retired as Tennessee's NRCS' State Conservationist. Kevin came to Tennessee in 2007 as the State Conservationist. He began with the USDA Soil Conservation Service, later changed to NRCS in June, 1977. He served in many positions over 41.5 years, including State Conservationist in Ohio and Deputy Chief of Management in headquarters. Kevin assisted in writing the 2002 Farm Bill. Because of his passion for Soil Health, he assisted NRCS in setting up the foundation of the current NRCS' National Soil Health Division.
In 2013, Kevin provided soil health leadership for Tennessee NRCS and partners. There were three priorities for Tennessee, Soil Health, Soil Health, Soil Health. Kevin is responsible for Yours Truly working with TACD as a Soil Health Specialist. At my retirement with NRCS, he asked me to take the position, and he worked with TACD to set up a cooperative agreement to fund my position. With his background, it is not surprising that Kevin practices soil health on his home garden. Kevin has moved 16 times during his 41.5 years. He has always had a garden. He has never tilled a garden. That is a testimony we do not hear very often with home gardeners. As I drive across the state, one area that I still see considerable tillage being practiced is in home gardening. I want to use this news article to say there are ways to improve soil health in gardening. Kevin's way is a way out of many ways to improve soil health. Following the principles of soil health will help gardeners improve soil health.
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Infiltration Improved by use of Cover Crops
Infiltration is the process of water entering the soil. Infiltration rate is a measure of how fast water enters the soil. Water entering too slowly may lead to ponding on level fields or to erosion from surface runoff on sloping fields. Reducing erosion and runoff also reduce surface runoff of fertilizers and chemicals such as herbicides. Fertilizers and herbicides are agronomic inputs to assist farmers in producing productive and profitable yields. The objective of applying nutrients and herbicides and other chemicals are to benefit the plant. If the inputs runoff, it is a loss to the farmer and the environment.
Plants need water and sunshine to produce crop yield. Infiltration is dependent on soil type, soil organic matter and aggregate stability or soil structure. As farmers utilize conservation practices that increase soil organic matter, soil health indicators such as soil structure, aggregate stability, and infiltration will also improve.
Rainfall simulators have become quite common in Tennessee. NRCS uses them to demonstrate how cover crops, no-till, and good grazing practices improve infiltration and reduces erosion. Below is an example of rainfall simulator at Milan No-till Experiment Station on Soil Health Plots.
The five trays used were from five treatments left to right, no-till only, NT wheat only, NT cereal rye and crimson clover, NT five-way mix consisting of cereal rye, wheat, crimson clover, daikon radish, and purple top turnip, and NT cereal rye and vetch. Rainfall simulations were run multiple times totaling 3" of water. All trays had good soil structure due to long-term no-till. As you can see by the back jugs showing infiltration, the 5-way mix infiltrated the best.
In another demonstration, the picture below shows minimum tillage (it is still tillage), no-till, over grazed pasture, conventional tillage tobacco with an excellent cover crop, and good grazing. Note that the good cover crop and the good grazed grass infiltrated and had little runoff compared to other treatments which had high runoff and poor infiltration.
So, all that is demonstration. Let’s put this to the test to real field conditions and real rainfall. Matt Griggs who is featured as the Number 3 in the Profiles of Soil Health Heroes on tnacd.org and also Matt Griggs update Profiles of Heroes. Matt recently sent me pictures in a rainstorm at his farm, true dedication.
Cover crops add more carbon and increases soil biology that increases better aggregates which results in much greater soil structure, pore space, thus better infiltration rates. Pictures below show long-term no-till with standing water, four years plus of cover crops and no-till with great infiltration, and the bottom picture show where the two plots come together. A picture is worth a thousand words. Cover crops with no disturbances from tillage improve soil function, such as here, infiltration.
Twenty Years of No-till. Two years of multi-species cover crops and no-till.
No-till alone on the left and No-till with cover on the right.
Soil health is improved by not disturbing the soil, keeping a root growing, keeping the soil covered, and diversity. The demonstrations and real farm application show continuous no-till with cover crops improve the soil’s ability to infiltrate water. Better water infiltration means better efficiency of water use and more stable yields. Contact your local NRCS office or Soil Conservation District Office for more information on improving soil health.