Browse on keywords: legume green manure NE
Search results on 03/25/18
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 unpublished manuscript, Plant Science Dept..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.
8897. Kroontje, W. and W.R. Kehr. 1956. Legume top and root yields in the year of seeding and subsequent barley yield.. Agronomy J. 48:127-131.
No significant difference in forage and root yields were measured among 6 alfalfa varieties and between hardy and non-hardy varieties. Forage production of Hubam and Madrid sweetclovers was equal. Barley yields following alfalfas and Hubam sweetclover were similar. Madrid depressed barley yields. Barley yield after vetches was superior to all other legumes. Contains good tables on root and top partitions under different cutting regimes.
9894. Cramer, C.. 1987. Water saving 'weed' replaces chem-fallow.. The New Farm, Sept/Oct 1987, p. 28-29..
Black medic is successfully being used in Montana as a reseeding annual legume in dryland rotations. The medic is protecting the soil from erosion, improving soil structure and water-holding capacity, disrupting weed and disease cycles, and reducing saline seep. Becauce medic is a shallow-rooted legume, it is supplying the soil with added nitrogen but only drawing water from the top 2 feet of the soil profile. This moisture is replaced by snow melt. The medic can also be a profitable hay crop.
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.