Browse on keywords: fertility NE
Search results on 05/20/13
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.
3652. Kmoch, H.G., R.E. Ramig, R.L. Fox, and F.E. Koehler. 1957. Root development of winter wheat as influenced by soil moisture and nitrogen fertilization.. Agronomy J. 49:20-25.
Although there was little top growth in November, root development was extensive for all moisture treatments. Roots which developed under less favorable moisture conditions were finer and had more and longer branches. April samples revealed that the primary root system was in the process of decay. Living roots were generally confined to regions of moist soil. Total weight of roots was highest where nitrogen had been applied. June samples revealed roots to a depth of 13 feet where moisture conditions were favorable. There was evidence of moisture depletion to a depth of 8'. N fertilizer increased root weights and moisture utilization at all moisture levels.
4067. Marsh, J.A.P., H.A. Davies and E. Grossbard. 1977. The effect of herbicides on respiration and transformation of nitrogen in two soils. I. Metribuzin and glyphosate.. Weed Research, 17:77-82.
The effects of metribuzin and glyphosate at 100 ppm on carbon dioxide evolution and nitrogen transformation in two soils have been investigated in the laboratory. Both herbicides reduced carbon dioxide evolution from Boddington Barn soil (organic carbon content 1.5%, pH 6.6) at some dates, but neither gave any consistent effects on Triangle soil (organic carbon content 4.0%, pH 5.1). Both metribuzin and glyphosate stimulated mineralization of nitrogen for at least 9 weeks. Only metribuzin on Triangle soil gave any indication of inhibition of nitrofication. Metribuzin degraded more rapidly in Triangle soil than in Boddington Barn.
4518. Molla, M.A.Z., A.A. Chowdhury, A. Islam and S. Hoque. 1984. Microbial mineralization of organic phosphate in soil.. Plant and Soil, 78:393-399.
Phosphate-dissolving microorganisms were isolated from non-rhizosphere and rhizosphere of plants. These isolates included bacteria, fungi and actinomycetes. The mixed cultures were most effective in mineralizing organic phosphate and individually Bacillus sp. could be ranked next to mixed cultures.
7770. Zentner, R.P., M.A. Stumborg, and C.A. Campbell. 1989. Effect of crop rotations and fertilization on energy balance in typical production systems on the Canadian prairies.. Agric., Ecosys., Environ. 25:217-232.
Non-renewable energy inputs, metabolizable energy output, and the energy efficiency of 10 spring wheat rotations were examined over 18 yr. Conventional tillage was used. Results showed total energy input per unit of land was lowest for the traditional wheat-fallow rotation (3482 MJ/ha), intermediate for N and P fertilized fallow-wheat-wheat (4470 MJ/ha), and highest for fertilized continuous wheat (7100 MJ/ha). Fuel accounted for 30-50% of the energy inputs, and fertilizer accounted for 15-49%. Pesticides were only 4-11%. Energy output to input ratios and the quantity of wheat per unit of energy decreased with cropping intensity. The average energy O/I was: F-W 3.6, F-W-W 3.3, cont. W 2.6. Rotations that included flax or cereal forage crops had the lowest energy efficiency.
7893. Sims, J.R.. 1978. Predicting nitrate accumulation in fallowed soils.. Agronomy Abstracts p. 162, Amer. Soc. Agron., Madison, WI.
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.