by Cammie Barden
You hear it everywhere — no-tilling practices creates better yield and better soil health. But how exactly does this happen and what can you do to get there.
James Hoorman, USDA NRCS Northeast Regional Soil Health Specialist, went through the basics in nutrient recycling and soil ecology at the 2017 Empire Farm Days.
“Brazil is one of our biggest competitors for soybeans,” Hoorman said. Hoorman also says that Brazil also has some of the poorest soil in the world but are still producing 50-60 bushels of soybeans with little fertilizer. The reason is because they went to pasture, participated in no-till practices and used cover crops.
Soils need a few things to be considered healthy. They need live plants growing year-round and a healthy microbial population to process energy. Soil also needs carbon, nitrogen and phosphorus and to absorb nutrients and fertilizer.
Sick soils are compacted with a high bulk density, poor water infiltration and are bare. These soils have low organic matter and a nutrient imbalance which makes it impossible to sustain plant growth.
“In traditional planting,” said Hoorman, “the soil only has plants for four or five months in a year. That means the soil is only producing energy one-third of the time.”
“Tilling soil gives a burst of CO2 but it needs to keep carbon in the soil. Nutrients and microbes are unstable in tilled soil,” said Hoorman. Tilling also essentially replants weeds as weeds love the disturbed soil and the release of Nitrogen which accompanies tilling. But once the nutrients leave the soil, it is extremely difficult to get them back.
To start to do this, it is recommended to utilize cover crops. “When cover crops die, they release nutrients. You need to kill them at the right time to get those nutrients,” said Hoorman.
But not only should they be killed at the right time, but it should be done with a shallow root turnover. “Let your cover crops grow out more root mass to build more carbon in the soil.”
An example of this is with soghham sudan grass. Cutting it but not killing it will increase the root mass under the soil. You would want to cut early and apply some manure and let it grow out to increase the root mass where all those nutrients the plant has absorbed are stored.
“Forty to 60 percent of Nitrogen can be lost from standing water,” Hoorman said. With nitrogen efficiency being roughly 30 to 40 percent, it is important to try and tie up that nutrient within a root system. Organic methods seem to be better at keeping the nitrogen in the soil than inorganic methods.
Carbon is also important to keep in the soil since it will help to anchor other nutrients from leaving.
When it comes to phosphorus, a soil high in iron will release the nutrient naturally. “Live plants plus carbon will keep phosphorus in the soil,” said Hoorman.
The things to keep in mind are very basic. You have to give time to have the changes show if you start to incorporate cover crops and no-tilling into your operation. Also overgrazing with animals is just as destructive to soil health as it will remove the roots and that will remove nutrients.
To keep the nutrients in the soil, leaving a thin, live crop growing on it will improve soil health over time.
Hoorman says to use cereal rye, any type of ryegrass, triticale, barley and wheat on a normal basis for a cover crop. The use of radish, oats and legumes should be restricted and kept at a maximum of one to two pounds per acre.
Keeping the soil in production throughout the year is the best way to ensure the nutrients are staying where they belong — in your soil.