Crop rotation, cover crop, and poultry litter effects on no‐tillage cotton profitability

Crop rotations, cover crops, and manures may enhance yields, improve soils, and provide other ecosystem services. However, farmers may be reluctant to adopt the aforementioned practices because of uncertain profits. This study determined the profitability of cotton (Gossypium hirsutum L.) rotated with other crops and also utilizing cover crops and poultry litter (PL). Whole-block treatments were 10 sequences of no-tillage cotton, corn (Zea mays L.), and soybean [Glycine max (L.) Merr.] at Milan, TN. Sequences were repeated in 4-yr cycles called Phases (Phases I, II, III, and IV) starting in 2002 and continuing through 2017 to assess effects of consecutive applications of sequences on cotton net returns (NRs). Split-block treatments included winter wheat (Triticum aestivum L.), hairy vetch (Vicia villosa L.), PL, and fallow. The ANOVA was used to determine treatment NR differences compared to continuous cotton and fallow for 2002-2017 and for each Phase. Including soybean and corn in rotation with cotton did not positively affect cotton NRs in Phases I, II, and III. Droughts may explain lack of yield and NR response in Phases II and III. However, including soybean and corn in the rotation provided higher cotton NRs in Phase IV (2014-2017). Better weather and improved soils with residue diversity in Phase IV may explain higher yields and NRs of cotton in rotation with other crops. For cover crops and PL, yield benefits and/or N fertilizer savings did not offset input costs, indicating monetary incentives may be needed for famers to include these practices in their cropping system.