Browse on keywords: legume WA green manure
Search results on 03/22/18
826. Bezdicek, D. and R. Lockerman. no date. Crop rotation and the response of cereal crops to nitrogen in the PNW. unpublished.
Experiments conducted at Pullman, WA and Bozeman, MT. Year 1 - legumes (rainfall -Pullman 500 mm, Bozeman 480 mm). Year 2 -Pullman winter wheat + N (rainfall 350 mm); Bozeman barley + N (rainfall 200 mm). Compared fababean, pea, lentil, chickpea, fallow at both locations. Pullman legumes were used as green manure, Bozeman legumes were harvested for seed. N fertilizer equivalents ranged from 30-86 kg/ha N at Pullman (fallow = 125) and from 27-81 kg/ha N at Bozeman (fallow = 53). All cereals responded to added N, although less so at Pullman. More N was removed in seed than was fixed. Seed legumes appeared to fix 50-100 kg/ha N. The rotation effect was more significant at Pullman. T: cereal yields; fertilizer N equivalent; moisture depletion.
835. Bezdicek, D.F.. 1990 Jan.. Crop rotation studies. presentation at STEEP Annual Review, Moscow, ID.
Several studies were described in which different legume green manures were grown before winter wheat and treated with different residue management. Wheat yields were consistently depressed following chemically-killed legumes in the first study, but not in the second. Under chemical kill, there was a 40 bu/ac wheat yield response to soil fumigation. Part of the fumigation response appeared to be higher available N. Also, it appeared that chemical kill may be increasing N mineralization. Results are being prepared for publication.
3589. Kirby, E.M.. 1987. Soil moisture depletion and wheat yield response from annual legumes in the Pacific Northwest. M.S. Thesis, Dept. of Agronomy and Soils, WSU, Pullman, WA.
Legumes included chickpea, spring pea, lentil, fababean, sweetclover, rose clover, black medic, barrel medic. Sweetclover depleted more soil moisture than other legumes. Wheat yield increased following legumes relative to that after barley. Highest yield followed legume green manure with additional fertilizer N. Grain yields were similar for fallow, lentil, pea, chickpea, and fababean. T: soil moisture depletion; yield, N content of soil and grain.
5065. Patten, A.G.. 1982. Comparison of nitrogen and phosphorous flows on an organic and conventional farm.. M.S. Thesis, Dept. of Agronomy and Soils, WSU, Pullman, WA.
Two adjacent farms, one organically managed and the other conventionally managed, located in the Palouse region of eastern WA, were studied for 2 years. Soil organic matter, total N, extractable P, and extractable K tended to be higher in the top 30 cm of soil from the organic farm. Mineral nitrogen in the top 30 cm of soil from the conventional farm was higher than or equal to that of the organic farm. Average long-term changes calculated in soil N and P pools resulted in substantial deficits of 44 and 14 kg/ha/yr, respectively, for the organic farm and 23 and 5 kg/ha/yr for the conventional farm. However, nutrients deficits were not reflected in lower soil N and P levels in the plot area tested on the organic farm as compared to the plot area on the conventional farm.
6228. Siddoway, F.H. and H.C. McKay. 1962. Tillage of sweetclover under dryland conditions.. ID Agr. Ext. Service Bull. #388 Combined Series.
Sweetclover used in 2 systems: spring grain - fallow (limited growing season, precip>14"); winter grain - fallow (precip <14", growing season adequate); 3-8 lb/ac biennial Madrid sweetclover; less weed growth after sweetclover kill than on summerfallow after wheat; sweep tillage worked well in dry years; moldboard plow was the most consistent kill; sweep left about 35% of sweetclover residue on surface; higher soil nitrates after moldboard plow; no signficant effect on soil moisture; yield correlated to soil moisture; yields 16-18 bu/ac; no control plots. T: nitrogen, soil moisture, wheat yield.
6989. USDA Soil Conservation Service. 1964. Technical standards and specifications.. Green manure, code 340.
Lists legume green manure species adapted to different land capability units, and the recommended management; alfalfa, sweetclover on drier, more eroded sites; red and white clover on wetter sites.
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.
8578. Pannkuk, Chris. n.d.. Estimating N credits for no-till wheat.. unpublished report, Land Management unit, USDA-ARS, Pullman, WA 99164.
N contributions from tinga pea (hayed or green manure) and black medic (green manure) of 70, 54, and 59 lb N/ac, respectively, were made on a subsequent spring wheat crop. All crops were planted no-till. Poor wheat stand establishment after the green manure tinga pea may have caused the low apparent contribution. Three nitrogen rates of 0, 50, and 100 lb N/ac were used. Wheat yields after legume at zero N were about twice as high as in continuous wheat, but the 100 N rate brought the latter yields up to par with the wheat after legume.