Browse on keywords: legume nitrogen NE
Search results on 03/21/19
4201. McCalla, T.M. and J.C. Russel. 1948. Nitrate production as affected by sweetclover residues left on the soil surface.. J. Am. Soc. Agron., 40(5):411-421.
7524. White, J.G.H.. undated. Grain legumes in sustainable cropping systems; a review.. unpublished manuscript, Plant Science Dept..
This paper briefly reviews the role that grain legumes can play in sustaining cropping systems. It presents various estimates of N fixation of grain legumes, with lupin and fababean showing the highest rates, followed by peas and lentils, chickpeas, and soybeans. Phaseolus beans are generally poor N fixers. Fababeans are more tolerant of soil mineral N than other species and will still fix large quantities of N when mineral N is present. Under drought stressed conditions, peas and lentils were more efficient in N fixation than fababeans. Only in lupins and fababeans was N fixation normally greater than the N removed in the seed. The roots and nodules of grain legumes are likely to be the greatest source of N for following crops. This N is often quickly mineralized within several weeks after harvest, and strategies are needed to prevent its loss. Grain legumes are also beneficial break crops, particularly for soil-borne diseases, and can help to control certain grassy weeds. Preceding grain legumes with a brassica crop has reduced the incidence of Aphanomyces root rot in peas, due to sulfur containing compounds. Most grain legumes suffer reduced yields if soils are compacted and poorly aerated. The paper contains numerous references and tables on nitrogen relations.
7662. Wright, A.T. and E. Coxworth. 1987. Benefits from pulses in the cropping systems of northern Canada. p. 108. IN: J.F. Power (ed.). The role of legumes in conservation tillage systems..
Investigated yield and N response in barley and wheat, 1 and 2 years after pulse crops of fababean, pea, and lentil. Overall yields were higher on fababean and field pea residues than lentils. Soil tests could not attribute yield differences among crop residues to differences in soil N levels at time of seeding. Nitrogen fertilizer equivalents for barley were 105, 85, and 50 lb N/ac for fababean, peas, and lentils. Legume residues influenced barley grain quality. In the second year following pulses, the dry matter yield, grain yield, and N uptake of wheat was 15% higher than in the continuous cereal sequence. Analysis of 3 completed rotation cycles showed that cropping sequences that included pulses were considerably more productive than the continuous cereal sequence in terms of net energy production and economic gross margin to cash costs. Field peas were the most effective first-year crop in terms of net energy production.
10079. Cowie, A.L., R.S. Jessop, D.A. MacLeod and G.J. Davis. 1990. Effect of soil nitrate on the growth and nodulation of lupins (Lupinus angustifolius and L. albus).. Austral. J. Expt. Agric. 30:655-659..
The effect of increasing external nitrate concentration on the nodulation of Lupinus albus and L. angustifolius lines was examined in two sand culture experiments. In the first experiment four lines, three L. albus and one L. angustifolius, were grown at nitrate concentrations of 0, 2, 8, 16, and 30 mmol/L for 49 days. Increasing the nitrate concentration reduced nodule weight in all varieties to a similar extent. In a second experiment, 18 L. angustifolius lines were grown at nitrate concentrations of 2 and 8 mmol/L for 49 days. The ratio of nodule weights at the 8 and 2 mmol/L nitrate treatments varied widely, from 23 to 71%, between the lines. There appears to be potential for selection of L. angustifolius varieties able to maintain nitrogen fixation at increased levels of soil N.
10088. Cowie, A.L., R.S. Jessop and D.A. MacLeod. 1990. Effect of soil nitrate on the growth and nodulation of winter crop legumes.. Austral. J. Expt. Agric. 30:651-654..
The relative effect of increasing external nitrate supply on the nodulation of three winter crop legumes was examined in a controlled environment experiment. Lupin, chickpea and field pea were grown at two nitrate concentrations of 2 and 8 mmol/L for 40 days. Shoot and root growth were not affected by nitrate contrations. Increased nitrate concentrations significantly reduced nodule number and nodule weight in all species. The inhibition of nodulation by increased nitrate concentrations was greatest in peas, followed by chickpeas, and least in lupins.
10576. Janzen, H.H. and G.D. Radder. 1989. Nitrogen mineralization in a green manure amended soil as influenced by cropping history and subsequent crop.. Plant Soil 120:125-131.
In a greenhouse study, surface soil from long-term experimental spring wheat rotations was amended with 15N labelled legume green manure and subsequently cropped (canola and spring wheat) or incubated. N mineralization from both the indigenous soil N and from green manure was suppressed in cropped soil. Net N mineralization in the uncropped and cropped treatments averaged 73 and 43 mg/kg, respectively. This difference was attributed in part to enhanced biological immobilization in the rhizosphere. These data suggest that short-term N mineralization is favored by fallowing soil after green manure application whereas N retention in organic matter is favored by immediate cropping.