Browse on keywords: fertility nitrogen phosphorus
Search results on 03/25/18
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.
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.
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.
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.
9617. Grant, C.A., E.H. Stobbe and G.J. Racz. 1984. The effect of N and P fertilization on winter survival of winter wheat under zero-tilled and conventionally tilled management.. Can. J. Soil Science 64:293-296..
A preliminary field study was conducted to investigate the influence of fall applications of nitrogen and phosphorus on winter survival of winter wheat on zero-tilled and conventionally tilled land. Nitrogen fertilization tended to decrease winter survival while phosphorus fertilization tended to increase survival. A N-P interaction was observed, with the derease in survival in response to added N being more evident in the absense of applied P. Balanced N-P fertilization may therefore result in highest winter survival in both conventionally tilled and zero-tilled winter wheat.
9706. Nyborg, M.. 1961. The effect of fertilizers on emergence of cereal grains, flax and rape.. Can. J. Soil Science 41:89-98..
Ammonium nitrate, ammonium phosphate and treble superphosphate fertilizers placed in a band with seeds of wheat, oats, flax and rape were found to delay and/or reduce emergence. Order of tolerance of these crops was oats>barely>wheat>rape>flax. The nitrogen ferilizer was more injurious than the two phosphate fertilizers, when applied on the basis of N and P2O5 content respectively. Injury to emergence increased with lower soil temperature. Damage to flax was apparently increased by soil micro-organisms. Injury to emergence was eliminated when fertilizers were broadcast or placed in a band one inch or more away from the seed.