Effects of rotation of cotton (Gossypium hirsutum L.) and soybean [Glycine max (L.) Merr.] crops on soil fertility in Elizabeth, Mississippi, USA

The effects of cotton (Gossypium hirsutum L.): soybean [Glycine max (L.) Merr.] rotation on the soil fertility levels are limited. An irrigated soybean: cotton rotation experiment was conducted from 2012 through 2015 near Elizabeth, Mississippi, USA. The crop rotation sequences were included continuous cotton (CCCC), continuous soybean (SSSS), cotton-soybean-cotton-soybean (CSCS), cotton-soybean-soybean-cotton (CSSC), soybean-cotton-cotton-soybean (SCCS), soybean-cotton-soybean-cotton (SCSC). The crop rotation sequences were followed continuous soybean, continuous cotton, cotton followed by soybean, soybean followed by cotton, soybean followed by two years of cotton, and cotton followed by two years of soybean. A weed control treatment of a non-glyphosate post-emergence vs. glyphosate post emergence was used in both crops. Soil samples taken prior to planting each year and in 2016 showed no differences in cation exchange capacity, organic matter, pH, or macro nutrient levels among the rotations, over the five sampling periods nor weed control methods used for either crop.