Browse on keywords: crop rotation tillage nitrogen
Search results on 04/25/18
4807. Nelson, A.L.. 1950. Methods of tillage for winter wheat.. WY Agr. Expt. Sta. Bulletin 300.
Fallow/winter wheat production decreased soil N by 33% in the top 6" over 35 years. Continuous cropping lost 24% of the soil N. Crop rotations using green manure every 4th year did not decrease the loss of soil N. Average winter wheat yields (bu/ac) over 34 years for 3 rotations were: oats/rye(GM)/winter wheat/corn - 12.9; oats/peas(GM)/winter wheat/corn - 12.7; fallow/winter wheat - 13.7; oats/corn/winter wheat/rye - 13.2; oats/corn/winter wheat/peas - 14.1; oats/corn/winter wheat/fallow - 13.2. It was observed that green manure took years to break down. Tillage with an eccentric one-way increased winter wheat yields 2 bu/ac over 10 years compared to plowing. The eccentric one-way conserved moisture. Continuous cropping resulted in winter wheat yields 55% of biennial yields following fallow. Soil moisture was 3-4% lower in October after continuous cropping versus fallow.
7242. Veseth, R.. 1989. Reduced tillage for green manure legumes. STEEP Conservation Farming Update, Summer 1989, p. 3-5.
Three tillages were compared for incorporating Austrian winter pea or red clover green manure: moldboard plow plus shallow disk; shallow disk twice; no-till. At each N fertilizer rate, winter wheat yields were slightly higher with reduced tillage than with conventional tillage. A 60 lb/ac N rate substantially increased wheat yields after green manure, while the 120 N rate gave little or no yield increase. With no N fertilizer, the yield of winter wheat after both green manure crops compared favorably with yield of no-till winter wheat after a seed crop of spring peas. Legume N uptake by a following wheat crop was not affected by residue treatment, but recovery of legume N from the soil was about 10% lower with surface application than with soil incorporation. Also, wheat yields after chemically-killed green manures were consistently lower, and could not be fully recovered with fertilizer N. The mechanism of this suppression is not known.
8374. Peterson, G.A., E. McGee, D.G. Westfall, C.W. Wood, and L. Sherrod. 1990. Crop and soil management in dryland agroecosystems.. Technical Bull. TB90-1, Dept. of Agronomy, Colorado St. Univ., Fort Collins, CO.
A large-scale field experiment was established in 1985 at 3 eastern CO locations to examine alternatives to the traditional wheat-fallow cropping system. All new treatments used no-till instead of tillage intensive management. Rotations include wheat-fallow, wheat-corn-fallow, wheat-corn-millet-fallow, and perennial grass. After five years, the more intensive cropping was giving greater grain output, nitrogen use efficiency, and water use efficiency than the wheat-fallow system. Organic matter levels also appear to be increasing. The research is also examining each strip plot at three landscape positions: toeslope, sideslope, and summit.