Many farmers employ practices such as reduced tillage and nutrient management on their corn, soybean, wheat and cotton land, say USDA economists, based on recent surveys of growers. Those practices can reduce erosion and nutrient runoff. Still, only 40 percent of the four major crops were planted on no-till or strip-till fields, says the agency’s Economic Research Service. No-till and strip-till rates were highest in the Southeast and among soybean growers. By far, no-till and strip-till (planting crops in a narrow band that leaves most of the field untouched) are the predominant forms of reduced tillage agriculture in the country. Other practices such as ridge tillage or mulch tillage add a few percentage points to the totals for each crop.
The ERS says 56 percent of corn, soybean, wheat and cotton land was on farms that used no-till or strip-till on all or part of the cropland. In some cases, no-till and strip-till were used only in combination with a specific crop, or on a particular part of the farm.
“While our analysis does not explain ‘partial’ adoption, we hypothesize that both crop and field characteristics play a role,” said the USDA report. “More broadly, we hypothesize that regional differences in no-till/strip-till adoption reflect both differences in crop grown and in climate, soils, and topography — factors that have already been shown to affect no-till adoption.”
Similarly to tillage practices, farmers often followed some elements of nutrient management, such as applying nitrogen fertilizer only during the growing season to reduce the risk of runoff. But only a fraction of corn and cotton land met all four criteria for management of that fertilizer.
Cover crops were planted on less than 2 percent of cropland in 2010 and 2011. The crops have received attention as a way to reduce erosion, build soil health and hold nutrients during the off-season. But some farmers say cover crops can be a challenge to establish in the late fall and a delay in starting field work in the spring for their money-earning crops.
“While best management practices are used individually by farmers, simultaneous adoption on all crop acres is rare,” said the USDA. “Combining no-till/strip-till, nutrient management, and cover crops on the same field provides multiple benefits, reducing the adverse environmental effect of crop production and improving soil health. However, successful applications require knowledge of how these practices are best integrated with specific crops, climate, and soil conditions.”