Browse on keywords: fertility yield
Search results on 05/25/13
1396. Cook, F.D., F.G. Warder, and J.L. Doughty. 1957. Relationship of nitrate accumulation to yield response of wheat in some Saskatchewan soils.. Canadian J. Soil Sci. 37:84-88.
Good correlation between wheat yields and soil nitrate levels. Estimated that a significant yield increase from N fertilizers can be expected when the nitrate accumulation value is below 50 ppm N in soil from stubble fields or 40 ppm N in fallowed soils.
2617. Hill, K.W.. 1954. Wheat yields and soil fertility on the Canadian prairies after a half century of farming.. Soil Sci. Soc. Am. Proc. 18:182-184.
T: soil properties X rotation; wheat yields X time
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.
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.
5181. Peterson, P.P.. 1919. Soil and climatic factors in relation to crop production on the Palouse.. ID Agr. Expt. Sta. Bull. #118.
8 rotations with N, P, K trts; clear response to N - 3 bu/ac on wheat at 200 #/ac NaNo3; manure response = 6 bu/ac; wheat yielded same after potatoes and fallow than peas or corn; made the most money with wheat/oats/peas ($51/ac/yr); ave. oat yield 1916 = 70+ bu/ac, 1918 = 26 bu/ac. Wheat, oats more affected by drought than corn or potatoes; this is the first mention of statistical methods. T: fertilizer response, rotation X net return.
5197. Peterson, P.P.. 1918. Soils of Latah County, Idaho.. ID Agr. Expt. Sta. Bull. #107.
Notes the great power of the soil to absorb falling rain; little cropping before 1870; native bunchgrass provided good spring pasture for cattle; history - 1887 first railroad to Genesee; very profitable line; wheat yields run as high as 70 bu/ac, seldom less than 20 bu/ac; 2 yr grain, then fallow for weed control; some interest in livestock; large farms 320-1200 ac; average 140 ac; field peas profitable in 1918; clover an option; response to S in alfalfa (gypsum 50-100 lb/ac). Low CacO3 in soil; low pH a future problem?
5791. Reichenberger, L. and J. Russnogle. 1989. Farming by the foot.. Farm Journal, March 1989, 113(6):11-18.
These articles report on the development of more landscape-intensive crop management in a number of states. Soil variability is a universal fact, and more growers are farming by it rather than field boundaries. Some are using grid systems of 3-10 acres to delineate management units. Computerized fertilizer applicators help make it feasible, as do new technology such as on-the-go nitrate and organic matter read-out, and yield mapping. Montana State Univ. researchers Jeff Jacobsen, Jerry Nielsen, and Pat Carr found yield variations in Montana wheat and barley fields ranging from 25-75 bu/ac in one field, 23-58 in another, and 22-35 in a third one. Each had received a uniform rate of fertilizer. Development of a soil variability map is a first step, and infrared photography can add more detail. Then create a soil management map that includes crop history. Then take soil samples from the management units to develop fertilizer recommendations. The GPS satellite system will enable very precises location in fields for intensive management. Farm machinery moving 7-10 mph would get a reading every 10-20'. Kansas State researchers have developed an on-the-go yield monitor for the combine. University of Nebraska researchers have a machine that recognizes weeds and only sprays herbicide then. Purdue researchers have an organic matter sensor that mounts on a tillage implement.
8675. Dalal, R.C. and R.J. Mayer. 1986. Long-term trends in fertility of soils under continuous cultivation and cereal cropping in southern Queensland. 1. Overall changes in soil properties. Austr. J. Soil Res. 24:265-279.
10070. Mahler, R.. undated. Catena management in northern Idaho.. unpublished handout for Extension agent training.
In northern Idaho, water is often not limiting to crop production. Also, nutrient use efficiency is lower than in drier areas. Where annual precipitation is <17", fall application of all N fertilizer is best. But as rainfall increases, nutrient use efficiency can be increased by applying a greater share of N in the spring. Fertility experiments have shown that growers are probably underfertilizing bottomland positions and overfertilizing slopes for maximum net return from fertilizer. Several questions need to be answered to help improve nutrient efficiency. Is the value 2.7 lb N/bu wheat linear? Research results indicate that only 2.4 lb N/bu is needed at 80-90% of maximum yield. Is residual N used as efficienctly by plants from surface layers versus subsurface layers? What is the best approach to estimating N mineralization rates in a soil? Rates in northern Idaho can vary as much as 100% depending on weather conditions.
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.