Browse on keywords: soil quality nitrogen fertilization
Search results on 06/24/18
5715. Rasmussen, P.E., R.R. Allmaras, C.R. Rohde and N.C. Roager, Jr.. 1980. Crop residue influences on soil carbon and nitrogen in a wheat-fallow system.. Soil Sci. Soc. Am. J. 44(3):596-600.
Seven crop residue treatments were initiated in 1931 to measure long-term residue managements effects on soil organic matter in a wheat-fallow cropping system on Pacific Northwest semiarid soils. Organic carbon and total N were measured at approximately 11-yr intervals over a 45-yr period to determine residue effects on the rate of change in soil OM content. Only the addition of 22.4 metric tons of manure/ha to straw residue before incorporating prevented a decline in soil N and C. The addition of 45 or 90 kg fertilizer N or of 22.4 metric tons of pea vines/ha to straw residue before incorporation reduced N and C loss when compared to straw only incorporation. Burning of straw in the fall following wheat harvest accelerated the loss of N, but not C. Burning of straw in the spring just prior to tillage had no effect on N or C loss.
7826. Zuzel, J.F., J.L. Pikul, and P.E. Rasmussen. 1990. Tillage and fertilizer effects on water infiltration.. Soil Sci. Soc. Am. J. 54:205-208.
Tillage and fertilization practices affect water infiltration. A long-term study at Pendleton, OR compared three tillages (plow, disk, and sweep) since 1940, and two rates of N (45 and 180 kg/ha) since 1962. Infiltration rates for plow, disk, and sweep were 17, 14, and 16 mm/h, respectively. Rates for the low and high nitrogen were 9 and 22 mm/h respectively. Results also indicate that surface sealing and soil frost are probably more important than tillage pans for infiltration. Residue cover eliminates any tillage effect on infiltration, while fertility is important in producing more crop biomass.
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%).