Browse on keywords: fertility nitrogen fertilizer placement
Search results on 06/24/18
2043. Fowler, D.B. and J. Brydon. 1989. No-till winter wheat production on the Canadian prairies: placement of urea and ammonium nitrate fertilizers.. Agron. J. 81:518-524.
A practical snow management system, which utilizes no-till seeding into standing stubble immediately after harvest, has permitted expansion of winter wheat production in western Canada. This study examined grain responses to urea and ammonium nitrate fertilizer banded and broadcast at seeding, or broadcast in the late fall or early spring. A moisture shortage biased the results. Fall banding prior to seeding helped reduce volatilization losses of urea (which were as much as 50%), but presented other problems and did not outperform broadcast ammonium nitrate.
9560. Brage, B.L., W.R. Zich and L.O. Fine. 1960. The germination of small grain and corn as influenced be urea and other nitrogenous fertilizers.. Soil Sci. Soc. Amer. Proceedings, p.294-296..
Field experiments comparing the use of urea to other fertilizers were performed. The fertilizer was placed with the seed in all but two experiments. Urea containing 2.5% biuret reduced stands of small grain by 30% when the equivalent of 20 lb N/ac was applied with the seed. Ammonium nitrate at 80 lb N/ac caused a reduction in stand of 10%. Stands were depressed by 25 and 60% when 40 and 80 lb N/ac, respectively, as reagent urea were used per acre. Urea, containing 10% biuret, applied broadcast at 160 lb N/ac, caused no damage to germination of either corn or barley. Urea was intermediate between ammonium carbonate (most damaging) and ammonium nitrate in a greenhouse germination trial. When fertilizer was mixed with the soil in the laboratory, considerable ammonia was evolved from the soil atmosphere by aeration when either urea, ammonium hydroxide or ammonium carbonate was used. Only traces of ammonia were removed from soils treated with either ammonium nitrate, ammonium sulfate or biuret. Ammonia gas formed from urea, and the contaminant biuret in urea, are therefore both instrumental in causing commercial urea to be toxic to germinating seeds.
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.
9715. Parsons, B.C. and F.E. Koehler. 1983. Fertilizer use by spring wheat as affected by placement.. Proceedings 35th Annual Northwest Fertilizer Conference, Pasco, Washington, July 17-18. p. 101-106..
High rates of soil erosion are a problem in the steep, dryland wheat producing areas of eastern Washington. Reductions in soil productivity have been measured as the result of top soil loss. One possible reason for lower yields in no-till is the less efficient use of applied fertilizer-N. With residues concentrated on or near the surface in no-tilled soil, decomposition is slower than would be expected if the residue was incorporated.
9740. Toews, W.H. and R.J. Soper. 1978. Effects of nitrogen source, method of placement and soil type on seedling emergence and barley crop yields.. Can. J. Soil Science 58:311-320..
An inverse correlation between seedling damage caused by urea drilled with the seed and soil cation exchange capacity was determined in eight field trials conducted on soils with a wide range in cation exchange capacity and pH. Seedling damaage increased with increasing rates of urea nitrogen and seriously affected potential grain yields of Conquest barely. Drilled NH4-NO3 caused greater grain yield increases than drilled urea in a manner inversely related to the seedling damage caused by urea. The magnitude of the difference was related to soil cation exchange capacity and pH which jointly influenced the quantity of NH3 volatilized.
9764. Varvel, G.E., J.L. Havlin and T.A. Peterson. 1989. Nitrogen placement for winter wheat in three fallow tillage systems.. Soil Sci. Soc. Am. J. 53:288-292.
Increased soil water storage with increasing amounts of surface residue in winter wheat-fallow cropping systems has not consistently resulted in higher grain yields in the Great Plains. Earlier results had suggested increased amount of surface residue may increase N immobilization and limit N availability, thereby reducing potential for use of the additional stored soil water. This study was conducted to determine if N placement below the zone of organic matter or surface residue accumulation would reduce N immobilization and increase yields.