Nearly 75 years ago, the Dust Bowl offered farmers here a valuable lesson: if their tillage practices failed to leave the soil covered, it would be lost forever.
Today, most farmers in this region still grow cycles of wheat and fallow … essentially resting their soil for an entire year after each harvest to give it time to collect enough rainwater to produce another crop. While this wheat-fallow rotation helps farmers keep wheat yields consistent from year to year, it also requires leaving the soil bare for up to 14 months at a time. That bare soil is subject to both wind and water erosion, and loses nearly 75% of its water storage to evaporation and weeds.
Lexicon of Sustainability worked with scientists at Colorado State University and farmers across Colorado and Nebraska to produce RESILIENCE, an education initiative that documents the stories of dryland farmers abandoning tradition in favor of more regenerative farming practices. Much of their inspiration comes from observing the efficient water-uses strategy of native grasses growing in the shortgrass prairie. They’ve learned to work with less water while building healthier soils, and to mimic nature by incorporating extensive crop rotations that enhance biodiversity. They also plant cover crops to keep the soil covered and increase soil organic matter while applying no-till farming practices.
In a time of increasing climate uncertainty, RESILIENCE provides farmers with a model for responding to a region’s specific challenges with adaptive strategies to help them reach their production goals not just today, but for generations to come
While the blue grama is the dominant and most drought-adapted grass in the shortgrass prairie, its understory is mixed with cool season grasses that adapt to a wide range of climatic conditions. Meanwhile, up to 90% of the biomass here is belowground, like an iceberg, allowing it to sequester huge amounts of carbon. By understanding how nature creates resilience, dryland farmers can use same diversity primciple to grow more food and stay in business whilefarming in the most variable climate in the country.
Semi-arid ecosystem of warm-season and cool-season grasses and forbs historically grazed by migrating bison
Carbon dioxide (CO2) is removed from the atmosphere by two basic mechanisms; either through absorption by oceans or by photosynthesis conducted by green plants. This process of removing carbon from the atmosphere is often referring to as CARBON SEQUESTRATION. Once stored, it is referred to as a CARBON SINK.
“Diversity in the shortgrass prairie is really important. You have to have more than one plant species to be able to respond to both really wet and really dry conditions. So I think that’s a big lesson for agriculture out here.”
USDA – ARS
In the High Plains, dryland farmers are constantly worried about drought. Instead of planting the region’s traditional wheat-fallow cropping sequence, farmers use more diverse crop rotations that break up weed and disease cycles, grow more food, make more money, sequester more carbon, and keep plants growing at different times of year to cope with the uncertainty of rain.
“We need to be able to put that rain in the soil where we can use it and not watch it run off. That’s one of the huge benefits of a crop rotation.”
New Raymer, IA
Growing a sequence of different crops on the same ground year after year.
While the typical wheat-fallow farming practices in this region result in one crop every two years, a new breed of dryland farmers experiments by growing a diverse mix of crops throughout the year. Instead of rotating between wheat and fallow, John incorporates cover crops into his rotation. They include kale, forage collards, grazing corn, cow peas, soybeans and vetch. When coupled with no-till practices, these farmers see benefits from a healthier soil ecosystem, one that captures and retains water, suppresses disease and pests, cycles nutrients, improves soil structure, and filters pollutants. Meanwhile, John’s neighbor tills his soil to control weeds, then leaves his soil bare for 14 months after each wheat harvest to recharge it’s store of water (absence of living plants in the soil means less for soil organisms to feed on).
Both tillage and a lack of residue left on the surface leave bare soils that ae easily eroded. Tillage can also destroy soil structure, decrease water infiltration and increase the likelihood of soil runoff.
Methods that keep soil covered and foster the development of nutrient-rich soils with greater water holding capacity are critical in dry farming regions like the High Plains.
Plowed land that is left idle, either to restore fertility or curtail excess production.
After each harvest, crop residue is left on the ground. It protects the soil from the erosive forces of wind and rain, and shades it from the sun. This blanket of crop residue is important; it can take hundreds of years to create a single inch of top soil. The residue also provides a natural buffer against the impact of raindrops and increases the total amount of water stored within a plant’s root zone. And with a no till system, corn is even planted directly into the crop residue, which provides nutrients while keeping soil exposure to a minimum.
We don’t really know in 50 years what this soil might be capable of,” Cole observes, “It’s a long healing process. Generations of tilled wheat-fallow degraded the soil, but that’s being reversed as no-till practices revolutionize dryland agriculture. Cole’s family is on the forefront of this change and they’re excited to seehow much the soil will improve over their lifetimes.
Growing crops without disturbing the soil through tillage.
Growing crops without disturbing the soil through tillage.
“After a long time of no-till and heavy crop residue you start to get the breakdown of organic matter at the soil surface. You can see all these earthworm and old root channels.”
New Raymer, CO
“When you have diversity in a cropping system,” Curt observes, “You keep the weeds and bugs off balance. I used to think these plants would compete but we’re finding now that they actually work in conjunction with each other. Some plants make nitrogen available and some plants make phosphorus available and some plants are better at retaining moisture. That diversity helps them all survive.
“To get the soil biology right, you have to have diversity above ground if you want diversity below ground. So, we have crop diversity, but the component that we’ve been missing is the livestock. it’s much more than just urine and feces. It’s the way their hooves interact with the soil and when they graze off a plant but don’t kill it, so the exudates are going out of the roots. Bison used to migrate in massive and dense herds, only eating the tops of their favorite plants as they went. By keeping our cattle at high densities and frequently moving them between fresh cover crop patches, they eat only a small amount of the total plant biomass. This allows the plants to regrow and benefit the soil, while also providing the cattle with a tasty and nutritious diet. All of these things stimulate the soil biology more than just the nitrogen and phosphorous that might be in the manure.”
“The beauty of grazing is we get the soil benefit of the cover crop and an income because the cattle are utilizing that cover crop and putting on pounds. It gives us ECONOMIC RESILIENCE as well as … SOIL RESILIENCE.”
A management strategy used to maximize forage growth by moving grazing livestock between a series of fresh pastures (often called paddocks) . The rest period provided these pastures give time for plants to regrow their foliage, which allows them to photosynthesize more plant tissue. After regrowth, livestock are again rotated though these pastures.
“The Western Great Plains have an amazing climate, Nolan says. “It’s the part of the country that has the largest year-to-year and day-to-day changes of almost any other part of the country. It’s an area of natural extremes to begin with, and that’s even before you add the next ingredient, which is climate change in action.”
Farmers in the High Plains depend on rainfall that averages less than 16”per year. While the effects of climate change are difficult to measure in this region, Nolan notes, “Anything that causes warmer weather with possibly fewer and larger precipitation events and possibly quicker onset drought – will require different approaches to how [farmers] manage the biological resources in [their] soil.
“Agriculture can affect not only how they respond to the climate as it may be changing but also how the atmosphere’s composition of carbon may in fact change over time as well. Agricultural practices can influence both sides of the climate system.” These practices can include both no-till and and reducing fallow periods in crop rotations to sequester carbon.”
Climate Change is a symptom of disrupted carbon and water cycles. These cycles have been altered by such human activities as agriculture, deforestation, and the mining and burning of fossil fuels.” – Judith D. Schwartz, Bennington, VT.
“I grew up in an agricultural area where the conversations that took place in the community were almost always weather and climate related,and that was the language I loved to hear.”
CSU Colorado Springs