The effects of tillage systems and crop rotations on soil water conservation, seedling establishment and crop yield

The long-term productivity of soils in Western Canada can be maintained, even enhanced, providing changes in production practices occur to reverse the current trends of soil degradation. A study was initiated in 1986 to investigate the interactions of tillage systems and crop rotations on soil water conservation, seedling establishment and crop yields. The three tillage systems used were zero (ZT), minimum (one preseeding tillage operation) (MT) and conventional tillage (fall and spring preseeding tillage operations) (CT). Three 4-yr crop rotations were superimposed on the three tillage systems: fallow-spring wheat-spring wheat-winter wheat, spring wheat-spring wheat-flax-winter wheat and spring wheat-flax-winter wheat-field pea. The amount of water conserved during the fallow period was not significantly affected by tillage systems. Under stubble cropping, ZT and MT increased soil water in the 0- to 60-cm soil layer by 9% and in the 0- to 120-cm soil layer by 6% over CT. When spring soil moisture under s...