Another key factor to effectively manage weeds is improving the competitiveness of crops with weeds. This can be accomplished by using competitive cultivars, higher crop seed rates, altered crop seeding dates, and selective fertiliser placement. These practices can be supplemented with the use of cover or green manure crops that inhibit weed growth through physical and allelopathic interactions. Experience has indicated that adoption of zero tillage cropping systems need not be limited by concerns over effective control of weeds. Certain weeds will proliferate with reduced tillage but they can be managed with timely use of herbicides and adoption of integrated weed management practices.
Conservation tillage is a key component of a more sustainable cropping system.
References Blackshaw, R. E., F. J. Larney, C. W. Lindwall, and G. C. Kozub. Crop rotation and tillage effects on weed populations on the semi-arid Canadian prairies. Blackshaw, R. E., G. Semach, X. Li, J. T. O'Donovan, and K. N. Harker. Derksen, D. A., R. E. Blackshaw, and S. M. Boyetchko. Sustainability, conservation tillage and weeds in Canada.