Cover crops are of increasing interest to producers in Wisconsin due to many potential agronomic benefits. These potential benefits include reducing soil erosion, providing and scavenging nutrients, weed suppression, improving soil health, reducing soil moisture losses, protecting water quality, reducing production costs and increasing yield. Cover crops have been utilized for many years in crop organic production. While cover crops are of increasing interest there are often challenges with their establishment. The increasing interest is shown through results from a 2013-2014 survey conducted by the North Central Sustainable Agriculture Research and Education (SARE) program with the Conservation Technology Information Center (CTIC). This survey indicated there has been a steady increase in cover crop acres since 2009 with 415,191 acres planted in the Mississippi river basin in 2014. Of the farmers surveyed 42.5% indicated that establishing cover crops was one of the biggest challenges. (SARE/CTIC, 2014) Some of this challenge may be due to herbicide carryover issues. Herbicide persistence factors include chemical properties of the herbicide, rate of application, soil pH, organic matter content, amount of surface plant residue, temperature, rainfall, and microbial degradation (Walsh, 1993). The objective of this study was to determine if persistence of commonly used residual herbicides applied in the spring to corn and soybean crops affect the subsequent establishment of cover crops in the fall.
Soil Science Extension
University of Wisconsin Madison