Managing and distributing residue for conservation tillage in the Pacific Northwest

In the agricultural regions of the Pacific Northwest, adoption of reduced tillage systems lags that of the United States as a whole. The limited adoption of this practice in the Pacific Northwest is due not only to economic and agronomic concerns, but also to the lack of trouble free, reliable seeding equipment for planting into the heavy residue encountered in this region. A project was initiated to develop a residue management strategy that would improve hoe-type no-till drill performance. Three types of combines, various seedbed preparation methods and different seeder attachments were investigated on a plot that yielded 85 bu/ac of winter wheat and had approximately 9,000 lbs/ac of residue. Acceptable no-till drill performance in terms of stand count, plant growth and yield potential was obtained when standing stubble was less than 8 in. tall and the residue was uniformly distributed. Uniformly distributing residue was the most important factor for maximizing direct seed drill performance in heavy residue. Drill attachments such as a coulter and a patent pending residue management wheel yielded mixed and improved results respectively. As expected, when nearly all residue was removed drill performance was excellent. Chopping the residue into fine, 1.25 in. long pieces provided stand counts and seedling yield potential parameters equivalent to those of removing the residue completely. It is not known whether cost of the energy required for this operation is economically viable, but does provide some hope for an improved residue management strategy over what is currently available.