Browse on keywords: fertility nitrogen fertilization
Search results on 05/20/13
8735. Haimanot, K.. 1977. Long-term effects of crop and soil management practices on crop yield and soil chemical composition.. M.S. Thesis, Dept. of Agronomy and Soils, Washington, ST. Univ., Pullman, WA 99164-6420.
The study site was located near Dusty, WA in the intermediate rainfall zone. Cropping system treatments were run from 1952 to 1970. Thirteen different cropping systems with three N fertilizer levels were used, including continuous cropping, green manures, and fallow systems. Wheat yields in rotation using 30 lb N/ac were higher than yields in an alfalfa rotation. Wheat yields were higher after Austrian winter pea green manure than after alfalfa or sweetclover. Per acre per year crop yields were highest for fertilized, continuous cropping. Soil pH increased with sweetclover GM and decreased with N fertilizer added. Significant increases in soil organic matter occurred in rotations with alfalfa (+0.08%), on winter wheat - fallow (+0.30%), and with winter wheat - spring wheat - fallow with N (+0.26%).