Economic assessment of irrigated and nonirrigated soybean cropping rotations on a clay soil

Experiments were conducted in Keiser, Arkansas on a Sharkey silty clay soil for three years to examine soybean, wheat, and grain sorghum rotations. Treatments also included selected variation of conventional versus no till and alternative wheat residue management. Both irrigated and nonirrigated strategies were investigated. Agronomic results show that irrigated soybean yields average about 1,344 kg ha(-1) (20 bu A(-1)) higher than comparably treated nonirrigated soybean treatments. Economic analysis using enterprise budgets reveals three top rotations regardless of irrigation: continuous monocropped soybean, wheat fallow followed by monocropped soybean, and wheat-soybean double-cropped with burned wheat stubble. Statistical analysis demonstrates the profitability of irrigation and the dependence of the most economical crop rotation upon weather conditions.