Browse on keywords: legume WA nitrogen fixation
Search results on 12/10/18
816. Bezdicek, D.. no date. (Influence of residual soil N on N2 fixation; N2 fixation of chickpeas). unpublished.
High levels of residual soil N decreased N2 fixation. There was a negative correlation between the fraction of plant N derived from N2 fixation and total mineralizable N and KCl extractable N. N2 fixation was reduced by about 2.8 kg/ha for each kg/ha of available soil N. Seed yield response from inoculation ranged from 5-70% and was negatively correlated with available soil N. Residual soil moisture in July was greatestfor large seeded legumes > forage legumes > winter wheat. T: N fixation in chickpeas.
846. Bezdicek, D.F., C. Root, and S. Smith. no date. Summary of data on nitrogen fixation in legumes in eastern and central Washington, 1981 and 1982.. unpublished preliminary report, Dept. of Agronomy and Soils.
This report summarizes field data from a number of irrigated and dryland locations in eastern WA. The studies examined nitrogen fixation and nitrogen cycling in the following crops: chickpeas, fababeans, lupins, peas, lentils, soybeans, medics, sweetclover, vetch, and clovers. Inoculation of chickpeas with Rhizobium resulted in 10-50% increases in seed yield. N fixation was estimated at 20-50 lb/ac. Fixation varied greatly depending on the Rhizobium strain. Fababean N fixation ranged from 0-150 lb/ac. With chickpeas, N fixation declined rapidly with increasing levels of soil available-N. In most cases, harvest of the chickpea seed resulted in a net loss of N from the soil. Rhizobium survival and nodulation was inhibited by chickpea seed treatment with Captan, but less so with Ridomil. Response of peasand chickpeas to added molybdenum was observed in several trials.
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.
3935. Mahler, R.L., D.F. Bezdicek, and R. Witters. 1979. Influence of slope position on nitrogen fixation and yield of dry peas.. Agronomy J. 71:348-351.
Total seasonal N2 fixation estimates: bottomland - 69; south slope - 22; ridgetop - 17 kg N/ha. Pea yields were 2100 kg/ha for the bottomland and 480 kg/ha for the ridgetop, and were related to soil moisture depletion of 22 cm and 9 cm respectively. Greater plant N and DM were obtained in the greenhouse when peas were inoculated with Rhizobium isolates from the north slope when compared to other isolates. T: soil water depletion
6518. Smith, S.C., D.F. Bezdicek, R.F. Turco, and H.H. Cheng. 1987. Seasonal N2 fixation by cool-season pulses based on several 15N methods.. Plant Soil 97:3-13.
Used 15N to determine N2 fixation by fababean, lentil, Alaska pea, Austrian winter pea, blue lupin, and chickpea. Mean seasonal N2 fixation by fababean, lentil, and AWP was near 80 kg N/ha, pea and lupin near 60 kg N/ha, and chickpea less than 10 kg N/ha. The net effects on the soil N pool ranged from 70 kg N/ha input by lentil to a removal of 48 kg N/ha by chickpea. Pulse crops often remove more N in the seed than they fix, leaving a deficit for the next crop. T: legume DM, total plant N, seed yield, seed N; N fixation values by different methods.
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.
8907. Bremer, E., R.J. Rennie, and D.A. Rennie. 1988. Dinitrogen fixation of lentil, field pea and fababean under dryland conditions.. Can. J. Soil Sci. 68:553-562.
N15 was used to study the N-fixation of several grain legumes in Saskatchewan, with all major soil zones represented. Indigenous rhizobia were incapable of supporting adequate levels of N2 fixation at most sites. Inoculation increased total dry matter, total N, and N2 fixation of all legume cultivars tested. Annual rates of N2 fixation were as high as 75, 105, and 160 kg N/ha for lentil, pea, and fababean, respectively on gray and gray-black soils in one year, but declined by an average of 5.3, 7.6, and 10.5 kg N/ha, repsectively, for every cm reduction in moisture use. Fababean fixed the most N under wetter conditions, while pea and lentil fixed the most under drought stress conditions. The amount of N fixed was not significantly correlated with soil nitrate levels in either year, perhaps due to the overriding effects of moisture. Estimates of the % plant N derived from atmospheric fixation ranged from 30-80%, with fababean generally the highest. The % from atmosphere was negatively correlated to soil nitrate for pea and lentil.