Winter cover crop production and water use in Southern Great Plains cotton

Abstract

Cover crops can provide several ecosystem services in agricultural cropping systems.Benefits may be enhanced with increasing cover crop biomass production. In waterlimited environments, feasibility of cover crop germination and production is not always certain. This study was conducted to determine differences in biomass production, water use, and water use efficiency (WUE) between monoculture cover crops and a mixture at Chillicothe, TX, in the Southern Great Plains under rainfed conditions in a continuous cotton (Gossypium hirsutum L.) cropping system over a 6-yr period. Evaluated cover crops included Austrian winter pea (Pisum sativum L.), crimson clover (Trifolium incarnatum L.), hairy vetch (Vicia villosa L.), hard red winter wheat (Triticum aestivum L.), and a grass/broadleaf mixture. Although cover crops were planted after optimum planting dates and under varying climatic conditions, biomass production was 2863, 2480, and 2301 kg ha −1 for the mixture, pea, and vetch, respectively. Peas and the mixture were the most consistent, producing significantly greater biomass than wheat and clover but not more than vetch. The mixture resulted in greater WUE than wheat. Clover resulted in reduced biomass production and WUE than vetch, pea, and the mixture over the study period. A cover crop mixture did not produce significantly greater biomass or significantly increase water use efficiency compared with vetch and pea. Under dryland conditions, peas, vetch, and a mixture were shown to be viable cover crop options in Southern Great Plains cotton systems, performing as well as a wheat cover crop.

Agronomic and economic impacts of cover crops in Texas rolling plains cotton

“…Compared to NT without a cover crop, lint yields increased by 2.8% following a cover crop mix, 4.8% following peas, and 6.1% following vetch. As lint yields were not different following clover, DeLaune and Mubvumba (2020) reported that the clover cover crop had less biomass production and water use efficiency than the mix, peas, and vetch.…”

“…Although recorded precipitation was greater in 2015, increased precipitation did not correlate to increased lint yields as cotton was planted late and adverse environmental conditions were endured during the growing season. Mean cover crop biomass production from 2012–2017 was 748, 1,562, 2,301, 2,480, and 2,863 kg ha –1 for clover, wheat, vetch, pea, and the mix, respectively (DeLaune & Mubvumba, 2020).…”

“…However, the mix was reduced to wheat, rye, pea, and vetch in 2015 due to lack of performance from other species in previous years. Complete cover crop planting and biomass production details are provided in DeLaune and Mubvumba (2020). Generally, cover crops were drill‐seeded (25.4‐cm row spacing) after cotton harvest each year in late October through late November and chemically terminated in late April each year.…”

Winter cover crop impact on soil health in Texas Rolling Plains dryland cotton

“…However, the extended duration of time between cover crop termination and the planting of the winter wheat cash crop were not the same as our study in which cover crops were immediately planted following cotton harvest. Although not quantified, the grass species of our cover crop mixture, rye, was dominant (DeLaune & Mubvumba, 2020). McDonald et al.…”

“…Two 0.42‐m 2 quadrats of cover crop herbage were then clipped at the 5 cm height from each of NT with cover crop treatments, weighed, and dried at 65°C for dry matter determination. Total C and N content was determined using combustion analysis using an Elementar Vario Max elemental analyzer (Elementar, Langenselbold, Germany; DeLaune & Mubvumba, 2020).…”