The adaptation of seven broadleaf crops to the dry semiarid prairie

To develop diversified cropping systems for the dry semiarid prairie, the a daptation of alternative crops must be known. This experiment compared the adaptation of seven pulse and oilseed crops - desi chickpea (Cicer arietinu m L.), dry bean (Phaseolus vulgaris L.), dry pea (Pisum sativum L.), lentil (Lens culinaris L.), mustard (Brassica juncea L.), safflower (Carthamus ti nctorius L.), and sunflower (Helianthus annuus L.) -; with spring wheat (Tr iticum aestivum L.), using two tillage practices - no-till and minimum till age, including both fallow and wheat stubble-field phases. It was conducted near Swift Current, SK 1992-1996, and on a commercial farm near Congress, SK 1994-1995. Tillage system had no consistent effect on plant densities, w hich were generally adequate. Mustard, desi chickpea, dry pea and lentil re quired fewer degree days (5 degreesC base) to reach anthesis, compared with wheat, while safflower and sunflower required more than wheat. Dry pea gen erally matured sooner than wheat, while lentil and mustard matured earlier than wheat only in years when near normal climatic conditions occurred. All other crops generally matured later than wheat, Safflower required an addi tional 400 degree-days and as a result presents considerable production ris k in the semiarid prairies. Dry pea grain yields averaged 103% of wheat whe n grown on fallow and 135% of wheat when grown on stubble. Chickpea, lentil and dry pea yielded 76%, 77% and 90%, respectively, of their Fallow-field yields when grown on stubble, indicating that the pulse crops have excellen t potential for intensifying cropping systems in the dry semiarid prairie b y replacing summerfallow in crop rotations. In contrast, wheat and mustard grown on stubble yielded only 66 and 61%, respectively, of fallow-field yie lds, suggesting they are not as well suited for stubble-cropping as the pul se crops. Low and highly variable yields were observed for safflower, dry b ean and sunflower in both field-phases, although the yields from dwarf hybr id sunflower in the latter 2 yr of the study appeared promising. Low seed N concentration in wheat indicated yields were limited by soil-available N i n most years, due to the generally wetter than normal growing seasons encou ntered during this study. The mean N yield (seed N concentration x grain yi eld) of dry pea was double that for chickpea and lentil, indicating that dr y pea fixed the greatest amount of atmospheric N-2. Water-use efficiency fo r dry pea averaged 9.4 kg ha(-1) mm(-1) compared with 7.4 kg ha(-1) mm(-1) for wheat. Dry pea, chickpea, lentil, mustard and sunflower have good poten tial for diversifying cropping systems in the dry semiarid prairie.