Iowa isn’t known as an early adopter with cover crops. But according to an article in Farm Journal recently, more than half of the acres in production in that state are leased. So, while farmers themselves may choose to do what’s best for the soil, owners may be reluctant to invest.
Nonetheless, the article went on to say that about 25 percent of Iowa farmers claimed to be using cover crops, though most said the acres committed to the conservation tillage measure were small…usually less than 100 acres.
That’s great news, because it suggests that owners are beginning to see that investment in conservation tillage brings dividends. According to the article:
Researchers say that landowners could benefit economically from farmer adoption of conservation agriculture, which can reduce in varying degrees the use of fertilizer, pesticides, fuel, equipment and labor. Crop insurance provides another potential opportunity in light of evidence that conservation agriculture can increase crop resilience to weather threats such as droughts or floods.
In the article, reference was made to a 2010 study by the University of Illinois (another latecomer to the value of cover crops) that concluded that the jury is still out on whether cover crops increase yields for corn and soybean crops (we believe it is conclusive that they do). But the study did say that cover crops significantly increase the amount of organic matter in the soil, which indicates soil health.
…it does increase the amount of sequestered soil organic carbon. Soil organic carbon stock gains were 30% higher for no-till, 10% higher for chisel plowed and 18% higher for moldboard-plowed plots.
“This suggests that soil organic carbon stock losses from tillage, water erosion and some disturbance or mixing during no-till planting, aeration, nitrogen injection in corn years and mineralization were less than the soil organic carbon gain from the cover-crop treatment,” says U of I soil scientist Ken Olson.