Browse on keywords: crop rotation green manure WA
Search results on 06/24/18
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 unpublished.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.
3875. Leggett, G.E. and W.L. Nelson. 1960. Wheat production as influenced by cropping sequence and nitrogen fertilization.. WA Agr. Expt. Sta. Bull. #608.
The average wheat yields resulting from annual cropping with optimum nitrogen fertilization were 13 bu/ac at Ritzville, 23 and Harrington and 29 at Dusty. The yields at Ritzville were too low for this practice to compete economically with the summer-fallow system. The average yields were high enough at Harrington and Dusty for this cropping system to be seriously considered. At Dusty annual cropping resulted in a yearly average yield of 6 bu/ac more than was obtained on fallowed ground. The yield of wheat following Austrian winter peas as a green manure crop at Dusty was greater than that obtained after alfalfa or sweetclover. Soil analysis revealed that nitrogen fertilization resulted in a carryover of nitrate-nitrogen for subsequent crops. This was especially notable under annual cropping and with high rates of application on summer-fallow. The protein content of the wheat was increased markedly by nitrogen fertilization. T: Nitrate-nitrogen in the soil before fertilization and the available soil moisture used by wheat as influenced by nitrogen fertilization cropping practice, Dusty. Yields of barley and wheat as influenced by alfalfa, sweetclover, and Austrian winter peas as green manure crops.
6684. Stephens, D.E.. 1944. Effect of tillage and cropping practices on runoff, erosion, and crop yields in the wheat growing areas of Washington, Idaho, and Oregon.. USDA-SCS. Conservation practices on wheat lands of the Pacific Northwest..
An excellent summary of the dryland experiment station research in WA, ID and OR. Describes research on stubble mulching, tillage implements, crop rotations, fallow, etc. The use of sweetclover or alfalfa-grass were encouraged. T: yield, runoff, soil loss by tillage, rotation, fertilizer.
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.
7761. Zentner, R.P., E.D. Spratt, H. Reisdorf and C.A. Campbell. 1987. Effect of crop rotation and N and P fertilizer on yields of spring wheat grown on a black chernozemic clay.. Can. J. Plant Sci., 67:965-982.
Including grass-legume forage, or legume green manure crops in the rotation increased yields of wheat grown on the unfertilized partial fallow by 15-24% and on unfertilized stubble by 33-71%; the yields were similar and sometimes higher than those obtained on fallow in the well-fertilized monoculture wheat rotations. Yields of fallow- and stubble-wheat were generally maintained over time with the application of recommended rates of N and P fertilizers, or by inclusion of legume-forage crops in the rotation, but yields of unfertilized stubble-wheat declined with time possibly reflecting declining soil fertility.
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%).
8804. Painter, K.M.. 1990. Does sustainable farming pay: a case study.. paper presented at Amer. Agr. Econ. Assoc. meetings, Vancouver, B.C., Aug. 4-8, 1990.
A wheat farm in eastern WA using green manure, minimal pesticide, and no commercial fertilizer for over 75 years, earned net returns averaging 25% lower than a typical conventional rotation for the area. Planting Austrian winter peas and grass cost $58 and $65 an acre, respectively, compared to $27 an acre for summer fallow. Fertilizer savings of $23 an acre were largely offset by these additional expenses. The choice of dry peas in the system results in fairly high chemical cost. When market prices were low, returns for the Lambert farm were 5% higher than for a conventional system, without support payments. The conventional system was some 30% more profitable with high prices, with or without support payments. Government payments increased net returns considerably more on the conventional farm, supporting the argument that programs encourage conventional high input systems. This study demonstrates that environmental and economic sustainability are not necessarily compatible.
9952. Zahradnik, F.. 1983. He nets $60,000 a year without buying fertilizer.. The New Farm, March/Apr 1983, p.22-24..
Don Lambert of Cheney, Washington, has not had any synthetic fertilizers used on his 780-acre farm since his family began farming it three generations ago. Yet the farm consistently produces 65 to 70 bushels of winter and spring wheat per acre. His farm also has up to four times less rill erosion than neighboring fields. Lambert's independence from fertilizer and the reduced erosion are due the use of Austrian winter pea as a green manure every third year in his rotation. He plants this cover crop in April and lets it grow until late July or early August. If spring wheat is to follow, he plows just enough to leave a heavy surface residue to protect against winter erosion. A soil test following Austrian winter pea showed enough nitrogen for 84 bushels of wheat per acre. The cover crop builds organic matter content of the soil, helps control weeds, and researchers believe it somehow unlocks phosphorus from the soil, making it more available to following crops.