Browse on keywords: fertility ID yields
Search results on 06/25/18
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.
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?
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 unpublished handout for Extension agent training.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.