Improving Soil Health in Lieu of Irrigation

This is the third in a series of “Profiles of Soil Health Heroes.” This profile is on Matt Griggs, Madison, Crockett, and Gibson Counties, Tennessee. Matt is owner and operator of a gently rolling hillside farming operation in West Tennessee. Matt’s farming operation consists of 1,600 owned and rental acres predominantly on loess and Coastal Plains Soils, slopes ranging from 2 – 6 %.

Matt farmed with his father up to 2005. Their cropping system was corn, soybeans, and cotton from 2000-2005. Since 2000, they practiced continuous no-till without full width tillage. Matt became the main operator since 2005 cropping season. Matt’s fields are fairly small with odd tree lines. The size and shapes of his fields make pivot irrigation options impractical.

Matt’s current crop rotation is corn, wheat-soybeans, cotton, and cereal rye production. Matt recently looked over old soil tests from the late 1990s; the fields averaged 1 – 1.25% soil organic matter at 0-6” depth. The Griggs had seventy acres of cropland that were very much eroded. In 2001, they sprigged hybrid bermuda grass for hay on those highly eroded soils. They maintained the hay fields until 2013 crop year. Presently, his entire operation is in annual crops.

Matt stated that the 13 years in bermuda grass transformed his soils to approximately 2.7 % soil organic matter. He said the soils were very dark at 0 - 2 inches, and functioned at a much higher level than they had previously. He terminated the bermuda grass and no-tilled wheat in 2013, where he yielded an average of 90 bushels per acre. Matt followed up with 45 bushels of double cropped soybeans. The dynamic changes in those soils have Matt striving to emulate those results with his crop rotations, cover crops, and no-till on other fields. 

As Matt advanced in his skills as a farmer, especially in his desire to improve the overall farm’s soil health, he has established goals for the farm. His goals are to increase soil organic matter with his current crop rotation system using no-till and cover crops. Matt understands sun light is energy, so another goal is to increase the utilization on his farm from the flow of energy. A typical cash crop only takes advantage of sunlight for 1/3 of the year. By providing continuous growth of plants through use of cover crops and crop rotations, Matt is maximizing the plants’ ability to make carbon from photosynthesis and cycling carbon to the soil. He realizes that keeping the soil covered reduces energy losses, in the form of heat that bare soil loses. By keeping something growing most of the year, he is maximizing the efficiency of energy flow through photosynthesis. Also, by keeping roots growing throughout the year, he is providing a more suitable environment for soil biology to cycle nutrients from the carbon-based system.

A third goal is to improve infiltration by continuing to adjust his cover crops to better provide roots and cover resulting in better soil structure. In fall of 2014, he has increased his acres of cover crop to over 1/3 of his operation. Matt planted over 420 acres of cover crops after corn and over 130 acres after soybeans and cotton. His soil tests for 2014 indicate soil organic matter levels are 2.5 – 3%. He is waiting on 2015 results thinking he may surpass 3% on some fields. Matt’s short-term goal for soil organic matter is 3.5% and long-term goal is 4%. This is quite remarkable when their baseline tests began at 1 – 1.25 % soil organic matter.

Observing organic matter increases, cation exchange capacity (CEC) increases, along with better infiltration rates, Matt desires to take advantage of infiltrating as much rainfall as possible. He says “locally we receive abundant rainfall, but sometimes the timing is not ideal. I want the soil health on my farm to be my irrigation.” He goes on to say that when “we receive one inch of rainfall, I want my fields to infiltrate more than 0.2” of rainfall. This mindset and determination is making a difference in his soil health changes as well to his bottom line.

Matt has grid sampled his fields in 2.5 acres blocks the last six years. He closely monitors the amounts on nutrients that are applied. He uses variable rate seeding and nitrogen application on corn. Each grid is tested one out of every three years. He has reduced nitrogen rates on cotton from 75 – 80 pounds per acre to 50 pounds per acre without any yield loss. His farm pH averages 6.5. He plans to apply lime by soil test every three years, but has noticed since organic matter levels are increasing; he is liming every 5 to 8 years. He credits the long-term no-till with additional covers for the changes in soils’ buffering capacity. In order to supplement his nutrients and to add additional organic matter, he recently began applying 1.5 tons of chicken litter per acre. He is carefully monitoring phosphorus and potassium levels. He is observing CEC increasing to approximately 5 - 15 milliequivalents per 100 grams of soil.

Wheat was added into the rotation of corn, soybean, and cotton in 2005. Matt liked the results of wheat to his rotation and began adding cover crops. After two seasons of adding wheat, his soil organic matter levels were averaging 2 - 2.5 % at 0 - 6” depth. In 2009 - 2010, he began experimenting with tillage radishes on very small acreages. In 2011, he tried seven acres in November. He quickly learned that he needed to plant much earlier. In 2012, Matt had a very dry year with corn only producing 50 bushels per acre. He planted acres of radishes, along with additional cover crops of rye and crimson clover. Matt described his tillage radishes as monsters due to the residual nitrogen not being taken up in the corn. He also had volunteer corn producing a considerable amount of biomass before frost.

He indicated that rye was chest-high by middle of March of 2013. The mix of clover did not do well because of late planting. Matt surmised that he needed more nitrogen in the fall for adequate production of cover crops, needed to use inoculants for legumes, and needed to plant earlier.

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In 2013, after experiencing with small acreages, Matt began planning for large acres of cover crops. He planted 420 acres comprised of 20 pounds per acre cereal rye, 4 pounds, crimson clover, and 5 pounds of Eco-till radishes per acre. He learned lessons in 2013 that he needed more rye, needed to innoculate clover, and the radishes needed to be planted earlier with more nitrogen.

Learning from his previous experinces, Matt recently planted six species of cover crops in the fall of 2014. He adjusted the planting dates and now always innoculate his clover. He is currently planting 30 pounds of rye, 8 pounds of crimson clover, 4 pounds of radishes 8 pounds of Austrian winter peas, one pound of rye grass, and one pound of vetch per acre. He plants his cover crops in mid-September after corn. He drills his cover crops whenever possible. He has flown on some cover crops after soybeans in early October, 2014. He currently believes it will improve from the current 50% stand. He also tried drilling a cover crop in early November. The rye is coming up but very short with little cover in January 2015. He plans to possibly add two more species in fall of 2015, buckwheat and canola. 

With only eleven years as the farm decision maker, Matt has made great strides in improving his farming operation and the health of his soils. With fields not suitable for irrigation, he sees his system as a buffering capacity for poor yields. Matt is not complacent on his gains. He constantly is reading magazines and searching other media, but credits a round table discussion on soil health sponsored by Brad Dention, NRCS District Conservationist, Jackson, Tennessee as the impetus for his successes. Matt states that by regularly meeting with other farmers to discuss their attempts, failures, and accomplishments have helped him venture to new ways of farming. He said that he wants to continue to learn and try new things. His goal is to produce 150 bushels of corn per acre with only 50 pounds of additional nitrogen. He believes his nitrogen from symbiotic rhizoben bacteria from legumes and organic nitrogen from increasing soil carbon will supply the needed nitrogen. He wants to increase acres of cover crops after soybean and cotton, and wants to improves seeding establishment by aerial seeding.