By Randall Reeder, Ohio State University Extension Agricultural Engineer (retired)
The federal government released a report on global climate change that predicts, among other disastrous results, that American farmers are doomed to failure. Drought, heavy rain, floods, and hot summers will destroy crop yields.
Farmers aren’t stupid. They know how to adapt to changing conditions. For example, there is a lot more acres of corn grown in Canada and our Northern Plains than 50 years ago.
Good news for the climate. If all cropland in the Midwest and Great Plains switched to continuous no-till (with cover crops) the rate of global warming would be SLOWED because carbon from the air would be sequestered in the soil as organic matter.
Crop yields for corn, soybeans and wheat (and whatever replaces them in localities) might increase despite dry summers and less groundwater for irrigation. The extra organic matter means soils would hold more water, reducing the impact of dry periods. Organic matter is a buffer that moderates soil temperature, regulates pH and stores nutrients.
With no-till, diesel fuel use is cut because of fewer tractor hours.
Having the soil covered with residue reduces evaporation, which reduces the amount of irrigation needed, which reduces the fuel needed to pump the water. Precisely injecting fertilizer means less is needed. And what is the main ingredient in anhydrous ammonia? Natural gas.
The November/December issue of the Journal of Soil and Water Conservation has three articles related to global warming and carbon sequestration. OSU Professor Rattan Lal and 14 co-authors studied “terrestrial ecosystems” and concluded that “conservation agriculture (no-till) is our best current bet for effective C sequestration.” Another article on cover crops points out an important issue where the payoff is long term: tenants, not the owner, farm about half of the U.S. prime farmland. A third article identifies an effect of “warming” in the Great Plains: winter wheat yields are decreasing in Texas and increasing in the Northern Plains states. (Maybe Texas wheat producers will switch to no-till cotton.) A shift to continuous no-till has major immediate costs which may include fertilizer injection equipment, cover crop seed, and a better planter.
Since the general population is a primary beneficiary (cleaner water, less dust, reduced algae in Lake Erie and less nitrogen in the Mississippi River watershed), perhaps tax dollars should cover part of that extra cost. A big chunk of that funding could come from redirecting support farmers currently receive.
Of course, global climate change means “global.” These no-till practices can be adopted in China, India, Ukraine, Africa and other regions to be a major factor in slowing or eliminating human-caused climate change.