Corp Nutrition and Productivity Under Long-Term Cover Crops, Crop Rotations, and No-Tillage Systems.

Conservation management practices are increasingly used to protect the environment and sustain agricultural productivity. The objective of this study was to examine the long-term interactive effects of cover crops, crop rotations, and no-tillage systems on crop nutrition and productivity. Three existing long-term field experiments in Tennessee were used for this study during 2014-2016. The first experiment is a cover crop/N rate/tillage experiment conducted on cotton continuously for 35 years. The combinations of no cover crop, hairy vetch, and winter wheat with two tillage systems of no-tillage and conventional tillage at the 34 kg N ha^-1 level with hairy vetch and 101 kg N ha^-1 with no cover crop and winter wheat were used in this study. The second trial is a crop rotation/cover crop study which has been continuously conducted for 14 years. Six rotation treatments of continuous corn, corn-soybean, continuous soybean, soybean-cotton, continuous cotton, and cotton-corn under no cover crop were used in this study. The third experiment is a soybean tillage study that has been conducted continuously for 32 years. Treatments of moldboard plow, no-till, and no-till with winter wheat as the cover crop were used in this study.ood River, Oregon ood River, Oregonoood River, Oregon ood River, Oregono Corn in rotation with cotton increased corn leaf P, Ca, S, Zn, Fe, and Cu, concentrations at R1 compared with continuous corn; while cotton rotated soybean had no effect on cotton nutrient levels relative to continuous cotton in 2015. No-tillage resulted in higher cotton yield than conventional tillage, but there was no yield difference among no cover crop and winter wheat at 101 kg N ha^-1 and hairy vetch at the 34 kg N ha^-1 averaged over 2014 and 2015. No yield benefit was observed on corn rotated with cotton, soybean in rotation with corn, or cotton rotated with soybean compared with their monocultures, respectively, in 2015. Soybean yielded similarly under moldboard plow, no-till, and no-till with winter wheat as the cover crop in 2015. In conclusion, no-tillage is beneficial for cotton production in west Tennessee from a long-term perspective.