An Agronomic and Economic Comparison of the Wheat-Corn-Fallow and Wheat-Sorghum-Fallow Rotations

Abstract

Winter wheat (Triticum aestivum L.) and grain sorghum [Sorghum bicolor (L.) Moench] in the central and southern Great Plains are often grown in a 3-yr wheat-sorghum-fallow (WSF) rotation. Corn (Zea mays L.) can be substituted for sorghum in northern areas but is believed to lack sufficient drought and heat tolerance for southwest Kansas and areas further south. However, interest in dryland corn is increasing. We conducted a study from 1992 through 1995 near Garden City, KS, to compare wheat-corn-fallow (WCF) and WSF. Four tillage systems were compared: all conventional tillage (CT); all reduced tillage (RT); all no-tillage (NT); and a CT wheat, NT corn or sorghum combination (CNT). Wheat yields were unaffected by rotation and tillage. Corn yielded more than sorghum in 12 of 16 tillage x year combinations, primarily due to above average precipitation. Corn yields were increased by RT and NT in 3 of 4 yr whereas they increased sorghum yields in only 1 yr. Average returns from WCF were $31.22/acre per yr, whereas those from WSF were $19.79/acre per yr. Returns of WCF exceeded WSF returns in 10 of 16 tillage × year combinations. Average income for CNT in WCF exceeded incomes from CT, RT, and NT by $6, $7.16, and $11.90/acre per yr, respectively. The CNT system in WSF produced $3.79/acre per yr more than RT and $6.14/acre per yr more than NT, but $5.84/acre per yr less than CT. Under the conditions of this study, WCF was superior to WSF in terms of yield and return. The CNT system- usually produced more return, particularly in WCF.