|ZHOU, XIA - University Of Tennessee|
|LARSON, JAMES - University Of Tennessee|
|SYKES, VIRGINIA - University Of Tennessee|
|ALLEN, FRED - University Of Tennessee|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/11/2021
Publication Date: 4/30/2021
Citation: Zhou, X., Larson, J., Sykes, V., Ashworth, A.J., Allen, F.L. 2021. Crop rotation, cover crop, and poultry litter effects on no-tillage cotton profitability. Agronomy Journal. 113:2648–2663. https://doi.org/10.1002/agj2.20661.
Interpretive Summary: Crop rotations and cover crops may enhance crop yields and improve soil quality, however, producers may be reluctant to adopt these conservation practices because of uncertain profits. This study set out to identify the profitability of cotton rotated with corn, soybean, cover crops, and poultry litter (subsequent winter weed growth emulating a cover crop). Cotton yields were collected from 2002 to 2017 and net returns (gross income minus expenses) were calculated for each cotton-rotation combination. Researchers found that rotations of cotton with soybean improved lint yields and net returns, but rotations with corn did not. Slight lint yield improvements were observed when using cover crops and poultry litter, but no net return improvement was observed relative to fallow systems. Therefore, prices would need to drop substantially to produce equivalent net returns to the status quo. Consequently, rotations and cover crop costs would need monetary conservation incentives for producers in order to make these best management practices economically feasible.
Technical Abstract: Increased crop rotations and cover crops may enhance crop yields, improve soil health, and provide other ecosystem services. However, farmers may be reluctant to adopt these conservation practices because of uncertain profits. This study determined the profitability of cotton (Gossypium hirsutum L.) rotated with corn (Zea mays L.), soybean (Glycine max L.) and bio-covers. Cotton yields were collected from 2002 to 2017 at Milan, Tennessee. Ten main plot cropping sequences were repeated in 4-yr rotations (Phases I, II, III, and IV). Five bio-cover treatments [fallow/control, poultry litter, winter wheat (Triticum aestivum L.), Austrian winter pea (Pisum sativum L. sativum var. arvense), and hairy vetch (Vicia villosa L.)] were applied as strip-plots. Net returns (NRs) were calculated for each treatment. ANOVAs determined yield and NR differences by phase, bio-cover, and rotation (including soybean or/and corn within a 4-yr rotation) in contrast to continuous cotton. Rotations of cotton with soybean influenced lint yields and NRs (P<0.01) averaged across all phases and bio-covers, but rotation with corn did not. Within Phase IV (2014-2017), rotations with soybean (corn) provided higher (P<0.01) lint yields and NRs than continuous cotton. Higher revenue due to enhanced cotton yields when rotated with soybean (corn) was the primary factor for improving NRs during Phase IV. Bio-cover treatments impacted (P<0.01) yields and NRs, with the control providing the highest NRs. Insufficient yield benefits and/or fertilizer savings with bio-covers did not offset their input costs, indicating monetary incentives may be needed for famers to include bio-covers in conservation crop rotation systems.