Browse on keywords: fertility phosphorus OR
Search results on 09/21/18
161. Albrecht, W. A. and N.C. Smith. 1939. Calcium in relation to phosphorous utilization by some legumes and grasses.. Soil Sci. Soc. Am. Proc., 4:260-265.
9609. Freyman, S. and M.S. Kaldy. 1979. Relationship of soil fertility to cold hardiness of winter wheat crowns.. Can. J. Plant Science 59:853-855..
In two controlled-environment experiments, N fertilizer applied to a Dark Brown prairie soil decreased cold hardiness of winter wheat, while P applied in the absence of N had little effect. When applied together, P counteracted the effect of N and produced plants as hardy as those that had received no fertilizer. The soil was rich in K; consequently applicaton of additional amounts of this element had no effect on cold hardiness. The correlation coefficient between dry weight of crowns and cold hardiness was not significant, but that between water content and LT was highly significant.
3070. Tanaka, D.L. and J.K. Aase. 1989. Influence of topsoil removal and fertilizer application on spring wheat yields.. Soil Sci. Soc. Am. J. 53:228-232.
In 3 of 5 years, soil removal treatments reduced spring wheat yields an average of 9, 28, and 45% for 0.06, 0.12, and 0.18 m soil removal treatments, respectively, over all fertilizer treatments. The data suggest that P was the most limiting nutrient and additions of N fertilizer without P resulted in small yield increases.
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.
5065. Patten, A.G.. 1982. Comparison of nitrogen and phosphorous flows on an organic and conventional farm.. M.S. Thesis, Dept. of Agronomy and Soils, WSU, Pullman, WA.
Two adjacent farms, one organically managed and the other conventionally managed, located in the Palouse region of eastern WA, were studied for 2 years. Soil organic matter, total N, extractable P, and extractable K tended to be higher in the top 30 cm of soil from the organic farm. Mineral nitrogen in the top 30 cm of soil from the conventional farm was higher than or equal to that of the organic farm. Average long-term changes calculated in soil N and P pools resulted in substantial deficits of 44 and 14 kg/ha/yr, respectively, for the organic farm and 23 and 5 kg/ha/yr for the conventional farm. However, nutrients deficits were not reflected in lower soil N and P levels in the plot area tested on the organic farm as compared to the plot area on the conventional farm.
5463. Pumphrey, F.V. and P.E. Rasmussen. 1982. Winter wheat fertilization in the Northwest intermountain region.. OR Agr. Expt. Sta., Circular #691. OSU, Corvallis, OR..
Most dryland wheat needs 40-100 lb/ac N. Early spring applications of N are 50% more efficient. Most wheat fields also need S. Most soils do not need P, but if needed half as much P needs to be applied if drilled with seed versus seperate application. T: N fertilizer effect on yield. N and S in grain and straw of a 50 and 125 bushel crop. Yields of wheat fertilized with different sources and forms of N. Soil N in non-fertilized soil as influenced by soil depth and sampling from planting to harvest. Soil N as influenced by soil depth, time of sampling, and fertilizer applications.
7057. Van Doren, G.S.. 1983. The form and distribution of soil phosphorus as affected by management and soil variability.. M.S. Thesis, Dept. of Agronomy and Soils, WSU, Pullman, WA.
Studies were initiated in the Pacific Northwest to determine long-term effects of cropping systems and tillage management practices on the form and distribution of soil phosphorus. Studies indicated that, in comparison with the native Palouse prairie, organic phosphorus in Palouse soils has declined more than 50% with cultivation and cropping. Stratification of phosphorus, with increasing concentration towards the soil surface, was found in no-till soil. A cropped soil which has been managed without utilizing chemical fertilizer showed total and organic phosphorus accumulations in the upper 30 cm of the soil profile with depletions lower in the profile. This was not evident in the adjacent, conventionally farmed soil. However, soil varibility often masked the effects of soil and crop management on phosphorus forms and distribution in soil. For example, soil series induced wider variation (significant at the 0.01 level) in phosphorus values than did management in a study which included detailed soil mapping. This study demonstrated that many experiments are not designed to quantify variations in soils; in fact, some are designed to mask soil differences by statictical analysis. Sequential testing is suggested as an appropriate experimental design to quantify soil variability.
7066. Vandecaveye, S.C. ad S. Anderson. 1934. Longevity of Azotobacter in soils treated with lime and superphosphate.. J. Am. Soc. Agron., 26:353-364.
Few Azotobacter in soils below pH 6.0, according to early studies; need several thousand colonies per gram of dry soil to get appreciable N fixation: liming increased Azotobacter in acid soils; phosphorus addition had no effect; large seasonal fluctuation in Azotobacter; highest numbers in spring and fall. T: Seasonal Azotobacter changes; effect of pH, lime, P.
7841. Koala, S., J.R. Sims, H. El-Attar, and M. El-Halfawia. 1988. Phosphorus deficiency in semi-arid tropics and implications for grain legume production. p. 205-216.. IN: R.J. Summerfield (ed.). World Crops: Cool Season Food Legumes..
8412. Pumphrey, F.V. and P.E. Rasmussen. 1982. Winter wheat fertilization in the northeast intermountain region of Oregon.. OSU AES Circular of Information 691, OSU, Corvallis, OR.
Early spring application of N is more effective than preplant. Rates can be reduced up to 50%. Most wheat needs S fertilizer (15-30 lb/ac) if N is added. Most soils supply enough P for high yields. There have not been significant yield responses to potassium or trace elements.