Browse on keywords: fertility legumes
Search results on 06/19/13
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.
2221. Goldstein, Walter A.. 1986. Alternative crops, rotations, and management systems for dryland farming.. Ph.D. dissertation, Agronomy and Soils, WSU.
This work covers a number of research areas, including the use of edible white lupine as an alternative crop, the use of black medic in rotation with spring peas and winter wheat (the PALS concept), performance of winter wheat as influenced by rotations, fertilization, and fumigation; rotational effects of medics; wheat interference with weeds; costs and returns of alternative systems; comparison of agronomic effects of conventional, organic, and biodynamic management. The PALS (perpetuating alternative legume system) concept was field-tested using a pea + medic - medic GM - winter wheat rotation with limited inputs of agrichemicals and tillage. This system was more economic using market prices of commodities at both a low and high yield level. With government support prices, the PALS system was competitive in the low yield situation, but not the high. Rotational effects appeared to suppress weeds in wheat with the medic compared to a continuous cereal system.
3418. Jordan, J.V. and G.O. Baker. 1959. Sulfur uptake and residual studies in northern Idaho using radiosulfur.. ID Agr. Expt. Sta. Research Bull. #42.
Compared plant uptake of S from gypsum, ammonium sulfate, ferrous sulfate, elemental S and green manure peas. Better utilization from gypsum than from elemental S. Green manure was as effective as inorganic sources. S fertilizer increased protein content of alfalfa and peas.
4377. McKay, H.C. and W.A. Moss. 1949. High protein wheat with conservation farming.. U. of Idaho Extension Bull. #181.
Emphasize need for legume - grass rotation to maintain soil productivity. Suggest a 7 yr sweet clover rotation or a 9 yr alfalfa rotation. Yellow sweet clover plus mountain bromegrass or slender wheatgrass; Ladak alfalfa plus smooth brome and big bluegrass (high rainfall) or crested wheatgrass (low rainfall); early spring seeding recommended without nurse crop; methods of establishment, plow sweetclover at 12-22" height; use sweetclover as a surface mulch to prevent erosion. T: soil moisture and sweetclover growth; wheat after sweetclover; yield and protein.
6738. Stickler, F.C. and L.R. Frederick. 1959. Residue paritcle size as a factor in nitrate release from legume tops and roots.. Agonomy J. 51:271-274.
Tested different particle sizes of tops and roots of alfalfa, sweetclover, red clover, and white clover. Coarse particles immobilized less N with alfalfa and white clover, but not red clover. Most treatments immobilized some N for the first 40-50 days, after which net nitrate release curves tended to become parallel. There was greater release of nitrate and recovery from tops than from roots. After 100 days incubation, recovery ranged from 43% for alfalfa, 34% for sweetclover, 25% for red clover, to 19% for white clover.
7161. Vandecaveye, S.C. and W.H. Fuller. 1941. Studies of different cultures of Rhizobium leguminosarum and of gypsum and straw for seed pea production.. Iowa St. College Journal of Sci. 15(4):415-423.
Tested 7 cultures of Rhizobium for nodulation and yield of Alaska seed peas. Also did a pot study with wheat straw and gypsum amendments. The field soil had never had peas before, but contained sufficient Rhizobium to inoculate peas. Seed inoculation tended to increase yields, but no culture was a sufficiently good N fixer to insure vigorous growth on soils low in available N. Soil amendments did not affect nodulation or growth. Yield differences were primarily due to variation in soil productivity.
8064. Welty, L.E., L.S. Prestbye, R.E. Engel, R.H. Lockerman, R.S. Speilman, J.R. Sims, R.A. Larson. 1988. Nitrogen contribution of annual legumes to subsequent barley production.. Applied Agric. Res. 3:98-104.