Impact of cover crop and soil apparent electrical conductivity on cotton development and yield

Authors: Vories, Earl; Veum, Kristen; Sudduth, Kenneth - Ken

Submitted to: International Conference on Precision Agriculture Abstracts & Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/13/2022
Publication Date: 6/26/2022
Citation: Vories, E.D., Veum, K.S., Sudduth, K.A. 2022. Impact of cover crop and soil apparent electrical conductivity on cotton development and yield. In: Proceedings of the 15th International Conference on Precision Agriculture, June 26-29, 2022, Minneapolis, Minnesota. Available: https://ispag.org/proceedings.

Interpretive Summary: Cotton is one of the major crops in the New Madrid Seismic Zone (NMSZ) of the U.S. Lower Mississippi River Valley region and soils in the region are generally quite variable. Areas of very high sand content and low soil organic matter levels are common. While cotton is a relatively low residue crop that can lead to reduced soil health over time, including winter cover crops can provide additional organic material that can help to improve and stabilize soil health. A field study of soil health and irrigated cotton production was conducted by ARS scientists from Portageville and Columbia, Missouri, at the University of Missouri Fisher Delta Research, Extension and Education Center in Portageville, MO, USA, beginning in 2019 with the objective to evaluate the effects of cover crops and reduced tillage on cotton crop growth and productivity in spatially variable soils. Treatments included conventional tillage without a cover crop, conservation tillage without a cover crop, and conservation tillage with a winter cover crop. The conventional treatment, which had the most soil disturbance due to the bed preparation just before planting, showed the greatest impact of soil variability while the plots with cover crops showed the least. The study is continuing, and these findings provide useful information to better meet the needs of agricultural producers and enhance cotton sustainability in the US and worldwide.

Technical Abstract: Cotton is one of the major crops in the New Madrid Seismic Zone (NMSZ) of the U.S. Lower Mississippi River Valley region. Soils in the region are generally quite variable, with areas of very high sand content, and low soil organic matter levels are common. While cotton is a relatively low residue crop that can lead to reduced soil health over time, including winter cover crops can provide additional organic material that can help to improve and stabilize soil health. A study of soil health and irrigated cotton production began at the Fisher Delta Research, Extension and Education Center in Portageville, MO, USA, in 2019 with the operating hypothesis that reduced tillage and cover crops will improve soil health indicators in cotton production systems. The objective of this study was to evaluate effects of cover crops and reduced tillage on cotton crop growth and productivity in spatially variable soils. Three treatments included conventional tillage without a cover crop (CONV), conservation tillage without a cover crop (CONS), and conservation tillage with a winter cover crop (COVER). While rainfall was less in 2021 than in 2020, the study was irrigated, which would minimize any effects of drought stress. The COVER treatment yield was significantly lower than CONV at the median soil apparent electrical conductivity (ECa) level in 2021, which could indicate the yield drag many producers report when first adopting cover crops. The CONV treatment had the most soil disturbance due to the bed preparation just before planting and showed the greatest impact of ECa variation for both normalized difference vegetation index (NDVI) and yield. The COVER treatment showed the least impact of ECa variation for both NDVI and yield. The study is continuing.