BENEFITS OF WHEAT STUBBLE STRIPS FOR CONSERVING SNOW IN SOUTHWESTERN SASKATCHEWAN

A limited and highly variable water supply is the major deterrent to annual crop production in southwestern Saskatchewan. This factor is partially counteracted by an alternate-year summerfallow system. However, the 21-month fallow period used in spring wheat-fallow rotations results in serious soil degradation. A 10-year study was carried out on a medium textured Aridic Haploboroll at Swift Current, Saskatchewan, to assess the advantages of using cereal trap strips (tall stubble), prepared at harvest, for conserving snowmelt water for stubble cropping. Hard red spring wheat (Triticum aestivum L.) was grown on zero-tilled land. Conservation of late-fall to early spring precipitation was variable and averaged 89 mm (3.5 inches); water intake into soil averaged 34% for standard short stubble compared to 50% for tall stubble. The 10-year average advantage in water conservation for tall stubble was 13 mm (0.5 inch), but it was as high as 48 mm (1.9 inches) in one year when the soil was extremely dry the previous fall. The 9-year average advantage in yield favoring trap strips was 79 kg/ha (71 pounds/acre), but more than 125 kg/ha (111.5 pounds/acre) in 3 years. In one of these 3 years, the advantage may have been due to a reduction of in-crop evapotranspiration. Because these cereal strip systems are easily and economically constructed, producers in these cold dryland areas are strongly encouraged to use them.