Changes in Soil Moisture with Cover Crops and Tillage: Impact on Cotton Yield and Quality

Authors: Sassenrath, Gretchen

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/3/2009
Publication Date: 11/1/2009
Citation: Sassenrath, G.F. 2009. Changes in Soil Moisture with Cover Crops and Tillage: Impact on Cotton Yield and Quality. Agronomy Abstracts. Paper Number 701, pp. 135.

Interpretive Summary: Changes in management practices alter the soil quality and moisture available for plant growth. Cover crops are an important management practices that improves soil organic carbon and increases the infiltration of water into the soil. We are examining changes in cotton quality and yield with use of cover crops and reduced tillage. We are measuring soil moisture throughout the growing season to determine the need for supplemental irrigation with and without cover crops. During wet years, cover crops form a mat over the soil surface, reducing the evaporation at the soil surface. The increased soil moisture hinders the planting operation, especially in heavy clay soils common to the area. During drier years, the retained soil moisture is a benefit. Sporadic rainfall in the area make management of water a challenge. While cotton yield and quality responded to irrigation and cover crops, the weather during the growing season also had a strong impact on final yield and quality.

Technical Abstract: The alluvial soils of the lower Mississippi River flood plain are highly productive, but low in organic matter. Use of irrigation in the area has increased in order to ensure adequate yield return. Use of cover crops has been used in other areas to increase soil organic matter and improve infiltration and stored water in the soil. We compared changes in soil water content for predominant soil types of the region with and without cover crops. During the winter, the entire soil profile is replenished with water. Cover crops act to decrease soil surface drying, and can hinder planting due to high moisture content in the seed bed during wet springs. During drier years, the cover crops improve the seed bed by retaining moisture. The highly variable weather patterns of the region make implementation and management of cover crops and water management challenging. Cotton yield and quality responded more to weather during the growing season than particular tillage or cover crop management.