Browse on keywords: crop rotation WA nitrogen
Search results on 10/16/18
765. Benson, V., W. Goldstein, D. Young, J. Williams, and C. Jones. 1988. Impacts of cropping practices on nitrogen use and movement.. Proc. Intl. Conf. on Dryland Farming.
Conventional and PALS practices were used as inputs for the EPIC model to simulate the effects of the systems over 108 years on an Athena soil. Total erosion over 108 yr under PALS was 40% less than the conventional system. Nitrogen loss through water was 25% less under PALS than conventional. Percolation loss of N was zero for both systems. Neither system had significant increase or decrease in yields after 108 yr of erosion.
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 unpublished.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.
1015. Bowren, K.E. (ed.).. 1986. Soil improvement with legumes.. Saskatchewan Agriculture, Soils and Crops Branch.
This excellent publication summarizes research over the past 40 years pertaining to the use of legumes for soil improvement in Saskatchewan. The role of legumes in maintaining soil nitrogen was crucial prior to available fertilizer. But their value extends beyond their nitrogen contribution to the improvement of soil physical properties. One study found the tillage draft requirement to be up to one-third lower where legumes had been a regular part of the rotation. The positive effects of alfalfa were measured for over ten years in a series of wheat crops compared to plots with no alfalfa. Over 17 years, the average grain yield from a wheat-wheat/clover-clover green manure rotation with no fertilizer were 30% higher that a wheat-wheat-fallow rotation with fertilizer. Moisture depletion by legumes is the biggest hurdle to their use in very dry areas. Adequate fertility for the legumes is necessary to maximize their benefit. Use of selected Rhizobium strains can improve nitrogen fixation, especially on acid soils. Several varieties of sweetclover are mentioned with adaptation to forage or green manure use. The booklet has numerous color photos and many data tables and figures.
2756. Huggins, D.R., W.L. Pan, and J.L. Smith. 1989. Improving yield, percent protein, and N use efficiency of no-till hard red spring wheat through crop rotation and fall N fertilization.. Proceedings, 40th Far West Fertilizer Conference,.
In a field experiment near Pullman, WA, all fall and split fall-spring N applications significantly increased percent protein and N uptake efficiency as compared to all spring applications, while yields were unaffected. Protein increase was attributed to enhanced late season uptake, due to better positional availability of deep soil N. In another experiment, yield of hard red spring wheat was 10% greater when no-tilled into Austrian winter pea stubble (for seed) as compared to winter wheat stubble, while grain N and percent protein were not affected. The difference in yield was not eliminated by optimized N rates, indicating other rotation effects.
2965. Ingham, I.M.. 1924. Effect of legumes in rotation upon the nitrogen content of the soil.. M.S. Thesis, Washington State College, Pullman, WA.
Soils at WSC farm were sampled to show residual effect of legumes upon following crops of wheat, and upon the N content of soil. T: Effect of legumes upon the following crops as shown by yields of wheat. Changes in the N content of soils after 5 years of crop rotations. Influence of various rotations on the N/C ratio of the soil.
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.
3835. Larson, C.A.. 1929. Comparative differences in the nitrogen and moisture content of various wheat varieties following alfalfa summer fallow and continuous wheat cropping.. M.S. Thesis, Washington State College, Pullman, WA.
Wheat grown on alfalfa sod has higher N, and generally higher quality wheat.
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.
5215. Pierce, F.J. and C.W. Rice. 1988. Crop rotation and its impact on efficiency of water and N use. p. 21-42.. IN: W.L. Hargrove (ed.). Cropping strategies for efficient use of water and nitrogen..
Crop rotations are viewed as beneficial, but not always economic, as long as commercial N supplies are unrestricted. True assessments of crop rotations are difficult due to their long term nature and indirect results. True assessments will only be obtained when all N pools are considered. There is a real lack of research that has determined either water or N use, and interaction as determined by crop rotations. The problem is one of funding and methodology. T: Distribution of organic N after 17 yr rotation.
6620. Speilman, R.S.. 1984. Nitrogen economy and agronomic evaluation of annual legume-cereal grain rotations.. M.S. Thesis, Plant and Soil Science, Montana State Univ., Bozeman, MT.
Legume biomass and seed yield were best for fababean, fieldpea, and chickpea. Potential for use of legumes for hay or silage. Barley yield after legumes was comparable to barley after fallow, and better than barley after barley or wheat. N contributions to the cropping system, except for field bean, were greater for legumes than for fallow. High N fertility levels from legume N plus fertilizer N resulted in premature soil moisture depletion. Optimum rotation performance will depend on balancing nitrogen fertility with expected available moisture.