The performance of the following rotation systems with various types of fallow was evaluated at the steppe zone of Transbaikalia, Russia, during 1997-2007: clean fallow [fallow without ground cover]-wheat-oat-oat for biomass (T1); fallow with yellow sweet clover [ Melilotus officinalis]-wheat-clean fallow-yellow sweet clover (T2); fallow with yellow sweet clover-wheat-clean fallow-wheat + yellow sweet clover (T3); fallow with yellow sweet clover-wheat-oat-oat + yellow sweet clover for biomass (T4); fallow with oilseed radish-wheat-oat-oat for biomass (T5); oat for biomass-wheat-oat-oat for biomass (T6); and wheat-wheat-oat-clean fallow (T7). Spring wheat yields and productivity values recorded for fallow with yellow sweet clover (T2, T3 and T4) were as high as those registered for clean fallow (T1). The highest profitability values were obtained with T2 (172.0%) and T4 (170.0%).
