Browse on keywords: yields WA
Search results on 06/19/13
1360. Cochran, V.L., L.F. Elliott, and R.I. Papendick. 1982. Effect of crop residue management and tillage on water use efficiency and yield of winter wheat.. Agron. J. 74:929-932.
3460. Kaiser, V.G.. 1965. Soil and water conservation for dry farmlands of Columbia River Basin.. Paper presented at Tri-state meeting of Supervisors and SCS personnel, Spokane, WA.
Discusses historical farming trends in eastern WA. Estimates yields to be 30% lower than their potential due to soil erosion. Cites past practices such as sweet clover use, hilltop windbreaks, and grass waterways that were very benificial. Proposes farm program change from acreage base to land capability base. More emphasis on spring wheat versus winter wheat, which reduces erosion by about 50%.
3762. Krauss, H.A. and R.R. Allmaras. 1982. Technology masks the effects of soil erosion on wheat yields - A case study in Whitman County, WA.. IN: Determinants of soil loss tolerance, Am. Soc. Agron./SSSA.
This study seperates yield increases due to technological advances from yield declines due to soil erosion. The average soil productivity decrease from erosion was 10.8 bu/ac. Analysis was carried out by land capability class to reveal different erosion impacts across the landscape. Real yields are increasing on 67% of cropland, and rapidly declined on 18% of croplands. T: yields of wheat in Whitman Co. for each decade since 1936. Winter wheat production and technology inputs in Whitman Co. from 1930-1979. Sheet and rill erosion in Whitman Co. from 1940-1977. Land capability subclasses and their estimated contribution to soil erosion in Whitman Co. Soil erosion and wheat productivity changes as related to soil capability subclasses in Whitman Co. Comparison of current yield distribution with that predicted.
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.
5423. Pubols, B.H. and C.P. Heisig. 1937. Historical and geographic aspects of wheat yields in Washington.. WA Agr. Expt. Sta. Bull. #355.
This report shows the low-to-high yielding regions within the state. It presents trends in yields from 1879 to 1937; and seperate data for spring vs. winter wheat from 1900-37. Graphs clearly show that the proportions of winter and spring wheat depend upon moisture conditions in the fall. For the 58 year period the weighted average yield was 19 bu/ac. The trend in yield during this period was horizontal. "Average yields were maintained by improved farming methods and superior varieties of wheat, even though soil resources were deteriorating. The critical status of the soil resources and their rapid decline suggest that effective soil and moisture conservation methods must be adopted in order to maintain yields." T: All wheat acres harvested, production and yield/acre 1879-1937. Wheat yield zones of south eastern WA. Distribution of wheat acreage, production, yield, 1929-32.
7424. Walker, D.J. and D.L. Young. 1982. Technical progress in yields - no substitute for soil conservation.. ID Agr. Expt. Sta. CIS #671.
Technological progress increased yield damage from erosion; higher yield reduction with successive erosion; yield damage from conventional tillage in wheat-pea rotation estimated at $8 for one year; no assurance that technology will continue to offset erosion - induced yield losses; leveling off yields in the last several years. T: erosion and yield change; technology and yield.
10287. Bhatti, A.U., D.J. Mulla, and B.E. Frazier. 1991. Estimation of soil properties and wheat yields on complex eroded hills using geostatistics and thematic mapper images.. Remote Sensing Environ. 37:181-191.
Spatial variability of organic carbon, soil P, and wheat yields was measured in eastern Washington using classical statistics and geostatistics. Organic carbon content was estimated from Landsat Thematic Mapper images. Goestatistics revealed strong spatial correlations relative to classical statistics. The spatial patterns were associated with changes in surface organic matter content across the landscape resulting from extensive erosion.