Hold Water in the Soil
Storing water in the soil has been Steve Reimer’s mission for more than four decades. As a young farmer just starting out, he saw problems on his family’s farm near Chamberlain, South Dakota, that he hoped to correct.
“Back in the 1970s, we grew corn and small grains, and we also did tillage summer fallow,” says Reimer, who farms with his wife, Elaine. “We were seeing water running off the fields and taking topsoil with it. We wanted, instead, for the water to stay where it fell.”
The Reimers transitioned slowly toward no-till and the building of a more diverse rotation including cover crops. They also intensified the integration of cattle into the cropping system. The three components have worked together to help the Reimers build soil and to save water.
For their longtime soil-saving efforts, the Reimers were named Soil Health Champions by the National Association of Conservation Districts.
Yields have increased for the Reimers over time. Perhaps more importantly, so has the resilience of soils and plants, letting crops endure the region’s periodic hot, dry winds and bouts of drought.
A testing time came with the severe drought on the Northern Plains during the 2017 growing season. “Steve’s area only received 5 inches of rain from January 1 until the middle of August; there was very little spring moisture,” says Stacy Turgeon, district conservationist for the Natural Resources Conservation Service (NRCS) in Chamberlain, South Dakota.
“Despite receiving such a small amount of moisture, Steve’s crops were more resilient than some area crops receiving the same amount,” she says. “The water that falls on his soil stays where it is and infiltrates the soil profile. His practices help crops hold on longer during adverse conditions.”
Grassland pastures, too, have increased resilience to heat and drought after years of rotational grazing.
“In the middle of August, we had pretty good rains and very little runoff,” says Reimer. “Even though we didn’t receive very much moisture overall, the soils held a high percentage of that much-needed moisture where it fell, and we had a real nice regrowth of grass in the fall on our pastures.”
This is Reimer’s three-pronged management strategy for building soil and conserving soil moisture.
1. Leave residue on the surface. “Leaving a mulch on top of the soil helps the soil retain moisture,” says Reimer. “The mulch keeps the soil cool and doesn’t allow the soil moisture to evaporate so rapidly.” His long-term transition to no-till contributes to the building of soil residue.
The crops he grows by no-till include corn, soybeans, winter wheat, and oats for livestock feed.
“The sequence depends on the year and the needs of the cattle,” he says. “Because we integrate our cattle into the cropping system, our planting decisions are based on the tonnage of fiber we expect to be available in the pastures for that growing season.”
2. Incorporate cover crops into the rotation. The grazing of the cover crops provides feed for livestock, and the microorganisms that feed on the roots and residue of the cover crops further build soil.
Reimer plants multispecies cover crops in July after harvesting winter wheat. The diverse cover crop planting might include species such as oats, millet, red clover, brassicas like radishes and turnips, grazing sorghum, and annual ryegrass.
“We seldom plant the same cover crop mix every year,” says Reimer. “We work with our local NRCS office in developing the species mix for each year. It depends on the needs of the soil in various fields.”
3. Graze cow-calf pairs on cover crops. The Reimers’ R&R Cattle Co. produces Simmental, SimAngus, and Angus breeding stock for commercial producers. The cover crops are a source of high-quality feed intended to keep cattle performing well late into the fall.
“After planting the cover crops in July, they’re usually ready for grazing by the first to the middle of September,” says Reimer. “If weather permits, we can graze the cover crops into December.”
The cattle help the production system to strike a balance between maintaining surface mulch and ensuring the eventual breakdown and incorporation of residue into the soil profile.
“The cattle help manage residue,” he says. “Their hoof action helps break up residue, and after consuming plant material, their digestive systems further break down the residue and return the nutrients to the soil through manure and urine.” After years of practicing this integrated management process, soil organic matter has increased. “Our soils have gotten healthier,” says Reimer. “When we first started, our soils were testing around 2% organic matter. The organic matter in the soil has now increased to about 4%.
“As the organic matter increases, the number of earthworms in the soil is increasing,” he says. “Along with that, water-infiltration tests done by our local NRCS staff show that the water-holding capacity of the soil is improving.”
Increasing levels of microbial activity in the soil were illustrated by on-farm demonstrations done by Turgeon.
“On multiple farms, we buried white underwear horizontally about 3 inches deep, though any kind of cotton material would work,” she says. “We buried the material in mid-June and left it for 10 weeks. Typically, we advise leaving the materials buried for six to eight weeks before digging them up, but we left these longer because the soil was so dry.”
The material buried in Reimer’s fields showed a high degree of breakdown, illustrating robust microbial activity in the soil. The crop residue feeds these soil microbes, and they, in turn, break down and recycle residue into soil nutrients.
“Fields that have livestock incorporated into their system definitely show more [microbial] activity than ones that do not,” says Turgeon.
“Over time, we have enhanced the productive capacity of our soils, and that has helped to enhance the productive capacity of the cowherd,” Reimer says. “It all works hand in hand.”
Soil Microbes Do The Work
“I used to worry about leaving too much residue on the soil,” says Steve Reimer. “But two years ago, the Natural Resources Conservation Service set up a time-lapse camera in one of my soybean fields to show the rate of residue breakdown over the growing season.”
Before spring planting, both wheat residue and corn residue from previous crops appeared heavy enough to challenge the process of no-till seeding the field to soybeans.
“After the field was seeded and over the course of the growing season, the camera captured that heavy layer of mulch just shrinking into the ground,” says Reimer. “In time, the beans grew up, and their canopy covered the camera. The soil microorganisms were doing their work of recycling the residue.”