SOIL TEMPERATURE AND SOIL WATER UNDER ZERO TILLAGE IN MANITOBA

The influences of zero and conventional tillage on soil temperature and soil moisture were investigated on three soil types in Manitoba. When the straw was spread on the soil surface, zero-tilled fields were usually cooler than conventionally tilled fields. When the straw was removed by raking, the opposite was true. No consistent soil temperature differences occurred between conventional and zero-tilled soils when the straw was burned. Soil moisture was higher on the zero- than on conventionally tilled plots both when straw was spread on the surface and when the straw was removed by raking. No moisture differences occurred between the tilled and zero-tilled plots when the straw was burned. As the season progressed, differences in moisture and temperature decreased as the crop canopy developed, and as the straw and stubble disintegrated.