AN AGRONOMIC EVALUATION OF CONSERVATION-TILLAGE SYSTEMS AND CONTINUOUS CROPPING IN EAST-CENTRAL SASKATCHEWAN

Soil degradation in east central Saskatchewan is due primarily to freq uent summerfallowing, and the excessive use of tillage for weed contro l and seedbed preparation. A five year study was conducted at four loc ations to determine the agronomic viability of a crop-fallow and a con tinuous-cropping sequence under conventional (CT), zero (ZT), and mini mum (MT) tillage systems using cereal and oilseed crops. Similar yield s were obtained with all tillage systems. Plant densities were not aff ected by tillage or cropping system. Differences in crop water use, an d consequently, yield were generally associated with differences in sp ring soil moisture (SpSM) between crop-fallow and continuous-crop trea tment, Overall, continuous-crop yields were 88% of yields for crops gr own on fallow when averaged over all crops and sites. The effects of t illage and cropping systems on SpSM were dependent on soil type. When differences in SpSM were observed, the increase was associated with ZT , MT, and fallow cropping. The study concluded that conservation tilla ge and continuous cropping are viable alternatives to traditional summ er fallow cropping practises, and refinements in crop and water manage ment could further improve productivity.