Use of Rotational Tillage for Corn and Soybean Production in the Eastern Corn Belt

Abstract

Farmers often rotate or alternate tillage systems to correct management problems associated with crop production. This study estimated the percentage of cropland fields in corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotations that were managed using some form of rotational tillage. The data set consisted of 14 748 corn and soybean fields that were surveyed by conservation personnel in 33 Illinois and 17 Indiana counties in 1994 and 1995. Estimates for continuous and rotational tillage and continuous no-till were generated by tracking fields over time. Continuous tillage, rotational tillage, and continuous no-till were used on 54.3, 29.8, and 16.1% of all fields surveyed, respectively. Due to a higher percentage of cropland managed in no-till soybeans (NTS), Indiana exhibited higher use of rotational tillage and continuous no-till than Illinois. In general, farmers more frequently rotated no-till soybeans with conventional tillage corn (CTC) than no-till corn (NTC) with conventional tillage soybeans (CTS). Based on 1995 planted corn-soybean rotation acreage, use of rotational tillage in Illinois and Indiana is estimated at 6.1 million acres. Research Question Farmers often rotate tillage systems to correct management problems associated with crop production. Examples include (i) improving yields associated with continuous no-till or continuous tillage systems, (ii) improving drying and warming of soils prior to planting, and (iii) eliminating field ruts caused by conducting field operations during wet soil conditions. While use of rotational tillage may eliminate these problems, it can increase soil erosion rates and prevent long-term improvements in soil physical and chemical properties. The objective of this study is to estimate the percentage of cropland in corn-soybean rotations in the eastern Corn Belt that is prepared using some form of rotational tillage. Literature Summary Use of no-till practices in the USA has increased by nearly 26 million acres since 1990. Adoption of no-till soybean production has been significantly greater than no-till corn production. In 1996, no-till soybeans accounted for nearly 28% of all planted soybeans while no-till corn accounted for less than 17%. In the eastern Corn Belt, over half of corn and soybeans are grown in rotation with each other. Consequently, the difference in no-till use suggests that conventional or full-width tillage is used more often for corn production than soybean production in corn and soybean rotations. No estimates exist on the use of rotational tillage and few studies exist that have examined the effects of rotational tillage on crop production systems. Rotating tillage systems has been shown to improve yields in certain environments compared with continuous no-till or continuous plow systems. Some soil physical properties (bulk density and total porosity) were also improved with use of the moldboard plow after 6 yr of continuous no-till. Study Description Statistically reliable cropland survey data were collected by county-level conservation personnel in Illinois and Indiana in 1994 and 1995. Cropland fields were located along county road routes that were not rerandomized each year, thus allowing the same fields to be tracked over time. Data on 14 748 corn and soybean fields from 33 Illinois and 17 Indiana counties were analyzed for the following cropping sequences: (i) no-till soybeans followed by conventional tillage corn, (ii) conventional tillage soybeans followed by no-till corn, (iii) no-till corn followed by conventional tillage soybeans, (iv) conventional tillage corn followed by no-till soybeans. Percentages were also calculated for continuous no-till and continuous tillage. Applied Questions How much rotational tillage is used in the eastern Corn Belt? Rotational tillage was used on nearly 30% of all fields surveyed, or approximately 6.1 million acres. By state, rotational tillage was used on 12.8% more of the fields in Indiana than in Illinois. This difference is probably due to the higher percentage of Indiana's cropland that is farmed using no-till systems. Overall, 16.1% of fields were continuously no-tilled for the 2-yr rotation. For a corn-soybean rotation, which tillage rotation is used most often? For both states, no-till soybeans in rotation with conventional tillage corn was the most commonly used tillage rotation. Specifically, use of conventional tillage corn followed by no-till soybeans accounted for 46% of all rotational tillage acreage while use of no-till soybeans followed by conventional tillage corn accounted for 34%. In contrast, use of conventional tillage soybeans in rotation with no-till corn was low, accounting for less than 7% of all fields.