Winter cover crop impact on soil health and nutrients in texas rolling plains dryland cotton

Authors: HUX, BRIAN - Texas A&M University; DELAUNE, PAUL - Texas Agrilife Research; SCHIRMARCHER, MARIE - Texas A&M University; GENTRY, TERRY - Texas A&M University; Mubvumba, Partson

Submitted to: Agriculture, Ecosystems and Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/18/2023
Publication Date: 3/16/2023
Citation: Hux, B.A., Delaune, P.B., Schirmarcher, M.T., Gentry, T.J., Mubvumba, P. 2023. Winter cover crop impact on soil health and nutrients in texas rolling plains dryland cotton. Agriculture, Ecosystems and Environment. https://doi.org/10.1002/agg2.20352.
DOI: https://doi.org/10.1002/agg2.20352

Interpretive Summary: Cover crops use during the fallow period in the Rolling Plains of Texas has been envisaged to enhance soil health and productivity under dryland cotton. Scientists from Texas A&M University and USDA Crop Production Systems Research Unit in Stoneville conducted a study to evaluate the impact of several cover crop species introduced in the winter fallow period of a dryland continuous cotton system to evaluate their effect on soil health. This study assessed several treatments: 1) conventional tillage (CT); 2) no-till (NT); and NT with the following cover crops: 3) wheat (W); 4) Austrian winter pea; 5) crimson clover; 6) hairy vetch; and 7) mixed species cover in a dryland cotton system. Soil parameters analyzed included soil organic carbon (SOC), total nitrogen (TN), inorganic N, water-extractable organic carbon (WEOC), water extractable organic nitrogen (WEON) and carbon mineralization (CMIN). There was no significant difference between CT and NT. The mixed species cover treatment had higher TN values compared to CT, and higher SOC, CMIN, WEOC, and WEON compared to both fallow treatments, NT and CT. Addition of cover crops to NT cotton systems enhanced NT soil health. The single-species Austrian winter pea showed the greatest overall soil health improvement. Cover crops have the potential to improve soil health in this region.

Technical Abstract: The Rolling Plains of Texas are historically semi-arid with sporadic, high intensity storms followed by periods of long drought. Fallow management is a common practice intended to store soil water, but leaves the bare soil exposed to erosive forces that can diminish the soil productivity. Cover crops in no-till (NT) agriculture have been proposed to increase soil health under environments with low precipitation as an alternative to fallow management. This study evaluated multiple treatments in a dryland cotton system including: 1) conventional tillage (CT); 2) NT; and NT with the following cover crops: 3) wheat (W); 4) Austrian winter pea; 5) crimson clover; 6) hairy vetch; and 7) mixed species cover. Soil samples were collected at 0, 3, and 6 weeks after cover crop termination and analyzed for soil organic carbon (SOC), total nitrogen (TN), inorganic N, water-extractable organic carbon (WEOC), water extractable organic nitrogen (WEON) and carbon mineralization (CMIN). For all parameters tested, there was no significant difference between CT and NT at any date or depth, so the addition of cover crops to NT cotton systems might be needed in order to enhance NT in regard to soil function. The multi-species (mixed species cover) treatment performed the best out of the cover crop treatments due to its combined benefits from grasses and legumes mix. The MC treatment had higher TN values compared to CT, and higher SOC, CMIN, WEOC, and WEON values compared to both fallow treatments, NT and CT. However, the single-species Austrian winter pea treatment showed the greatest overall soil health improvements by the soil parameters tested, and can be a useful alternative to fallow management under these dryland agriculture conditions.