Economic implications of reduced tillage and cover crops in the irrigated mid-South

Conservation cropping systems provide many ecosystem service benefits, but must improve or maintain profitability to be economically viable. This study was conducted to determine the sustainability of conservation tillage in continuous cotton (Gossypium hirsutum L.). The effects of subsoil tillage, strip-tillage, no-seedbed-tillage, and cover crops on irrigation costs and overall profitability in comparison with a conventionally tilled control were investigated. The study was located near Stoneville, MS, on a Dubbs silt loam (fine-silty, mixed, active, thermic Typic Hapludalf) and a Bosket very fine sandy loam (fine-loamy, mixed, active, thermic Mollic Hapludalf). The lowest costs per hectare were realized when the no-seedbed-tillage with winter fallow treatment was used. Using a cover crop reduced irrigation expenses by $18.29 ha⁻¹ compared to the conventionally tilled control (p > F = 4.1 × 10⁻⁵). However, revenues were reduced by $279 ha⁻¹ where cover crops were sown (p > F = 0.043), and returns were reduced by $497 ha⁻¹ (p > F = 0.007). The strip-tillage and no-seedbed-tillage systems with winter fallow reduced overall variability of production when compared to the conventional control and treatments with a cover crop. Adopting the no-seedbed-tillage with winter fallow system provided the best returns by reducing expenses and lowering variability.