Browse on keywords: fertility WA ID
Search results on 12/10/18
3885. Leggett, G.E., H.M. Reisenauer and W.L. Nelson. 1959. Fertilization of dryland wheat in eastern Washington.. WA Agr. Expt. Sta. Bull. #602.
This bulletin presents the results of 5 yrs of experimenting with the fertilization of wheat. During 1953-1957, 112 fertility experiments were conducted on dry land wheat throughout eastern Washington. Nitrogen fertilization significantly increased yields in 92 of the 112 experiments conducted. Whether nitrogen fertilization increased wheat yields depended largely on the amount of moisture available to the crop. Because of the decline in soil organic matter through years of cropping, the amount of available N released by soils is no longer adequate to support high wheat yields. The introduction of high yield varieties and improved tillage has increased yield potential, and this has increased the demand for N. Application rates (lb N/ac): <10" rainfall - 20-40; 10-15" - 20-60; >15" - 30-80. Different types of N fertilizer did not change yields. T: Summary of the effects of N on wheat yields, 1953-57; effect of N on yield from fallow ground.
4002. Mahler, R.L., A.R. Halvorson and F.E. Koehler. 1985. Long-term acidification of farmland in northern Idaho and eastern. Comm. Soil Sci. Plant Anal. 16:83-95.
Soil acidification from N fertilizer first noticed in 1960's; has accelerated since then; critical levels for crops: alfalfa 5.6, wheat 5.2, peas and lentils 5.4; current wheat varieties relatively acid intolerant; liming needed to grow alfalfa on 45% of northern ID fields; acidification may be shifting weed pressures, encouraging diseases, decreasing availability of P and Mo. T: map of pH changes, N fertilizer use.
4621. Muehlbauer, F.J. and R.F. Dudley. 1974. Seeding rate and P placement for Alaska peas in the Palouse.. WSU Coop. Ext. Bull. #794.
Studied seeding rate and placement; optimum seeding rate seemed to be 150 lb.ac; when soil P was higher than 4.8 ppm, no yield response; banded P was effective when soil test was low. T: seeding rate, P fertilization.
8354. Veseth, R.. 1990. Winter wheat nitrogen management in the 18-25 inch precipitation zone.. STEEP Extension Conservation Farming Update, Spring 1990, p. 9-11..
In this rainfall zone, treatments with 25-50% if the N banded below the seed at planting and the remaining N spring broadcast, produced significantly higher yield and N use efficiencies when compared to the average of all other treatments. At the lower precipitation, more N should be fall-applied than in the wetter areas. Banding avoids some of the weed stimulation caused by broadcast N applications.
9569. Cochran, V.L., L.F. Elliott and R.I. Papendick. 1980. Carbon and nitrogen movement from surface-applied wheat straw.. Soil Science Soc. Am. J. 44:978-982..
The N immobilization potential of surface-applied wheat straw as compared with incorporated straw was evaluated in the laboratotory with soil columns. The columns were leached weekly and C and N content of the leachate was determined. Leachate C/N ratios for straw alone exceeded 20:1 on several occasions and reached a maximum of 56, indicating a potential for N immobilization. Less than 5% of the total C in the straw was recovered in the leachates, providing an inmobilizatoin potential of <5 kg N//ha. Leachate C/N ratios from 1-, 2-, and 4-cm deep soil columns with surface-applied wheaat straw and no ferilizer N ranged up to 55:1; 30:1 and 22:1, respectively, while the highest leachate C/N ratio from the 4-cm mixed straw treatment was 30:1. A significant percentage of mineralized N was immobilized in the 1 and 2 cm of soil by surface residues. Much less N was immobilized in the 4-cm soil columns. Thus, placement of fertilizer N several centimenters below the soil surface would alleviate possible N immobilization from organic C leached from surface crop residues. The amount of applied N recovered in the leachate during 9 weeks of incubation ranged from 60 to 70% for all soil column treatments with or without surface straw. There was no significant difference between treatments. In contrast, the recovery of applied N from the mixed straw treatment was only 36% indicating a much greater potential for N immobilization with mixed than with surface straw. The quantity of the fertilizer N added probably masked the immobilization potential of surface residues. Fertilizer N stimulated early release of C from the straw alone treatment. But after 9 weeks of incubation the overall C loss from both fertilized and unfertilized straw was about 30%.
11116. Wegner, G.. 1992. The benefits of biosolids.. Wheat Life (April 1992), p. 11-13.
Dryland cereal farmers are beginning to test the value of biosolids (treated sewage sludge) on their fields. Gary Wegner has found that his crop yields are increasing where biosolids are applied, perhaps due to addition of trace elements such as zinc. Also, biosolids add organic matter which improves soil structure and reduces erosion potential. Biosolids are a free source of nutrients for farmers, but not enough are available to cover very many acres each year.