Browse on keywords: fertility WA P
Search results on 12/10/18
3288. Pan, W.L. and A.G. Hopkins. 1991. Plant development, and N and P use of winter barley. I Evidence of water stress-induced P deficiency in an eroded toposequence.. Plant Soil 135:9-19.
Winter barley was grown at three landscape positions of a representative toposequence in the Palouse region to identify soil factors which limit plant development and nutrient use efficiency in the eroded slope positions. Subsurface P was severely deficient at eroded ridgetop and sideslope positions. Drying of surface soil during the growing season prevented roots from using much surface applied P. This moisture stress-induced P deficiency suggests that deep placement of P is needed to build subsoil P levels for enhanced productivity on these eroded sites.
915. Boawn, L.C., C.E. Nelson, F.G. Viets, and C.L. Crawford. 1960. Nitrogen carrier and nitrogen rate influence on soil properties and nutrient uptake by crops.. WA Agr. Expt. Sta. Bulletin 614.
Irrigated soils near Prosser. Native soil. Soil pH dropped from 7.4 to 6.0 (0-8") with ammonium sulfate at 160 N/ac. Effect of ammonium nitrate was less, while calcium nitrate had no effect on pH. Fertilizer N recovery was 75-85%. N application increased Mn uptake, but no trends for other elements.
1015. Bowren, K.E. (ed.).. 1986. Soil improvement with legumes.. Saskatchewan Agriculture, Soils and Crops Branch.
This excellent publication summarizes research over the past 40 years pertaining to the use of legumes for soil improvement in Saskatchewan. The role of legumes in maintaining soil nitrogen was crucial prior to available fertilizer. But their value extends beyond their nitrogen contribution to the improvement of soil physical properties. One study found the tillage draft requirement to be up to one-third lower where legumes had been a regular part of the rotation. The positive effects of alfalfa were measured for over ten years in a series of wheat crops compared to plots with no alfalfa. Over 17 years, the average grain yield from a wheat-wheat/clover-clover green manure rotation with no fertilizer were 30% higher that a wheat-wheat-fallow rotation with fertilizer. Moisture depletion by legumes is the biggest hurdle to their use in very dry areas. Adequate fertility for the legumes is necessary to maximize their benefit. Use of selected Rhizobium strains can improve nitrogen fixation, especially on acid soils. Several varieties of sweetclover are mentioned with adaptation to forage or green manure use. The booklet has numerous color photos and many data tables and figures.
1165. Campbell, C.A., D.W.L. Read, R.P. Zentner, A.J. Leyshon, and W.S. Fer. 1983. First 12 years of a long-term crop rotation study in southwestern Saskatchewan.. Can. J. Plant Sci., 63:91-108.
On a crop-year basis, continuous wheat yields averaged 75% of fallow yields when recommended rates on N and P fertilizers were applied. Yield variability was lower for rotations that included high proportions of fallow than for continuous-type rotations. Fertilizer N applied at recommended rates increased yields of wheat grown on fallow by an average 5% and wheat grown on stubble by an average 7%. Application of P fertilizer at recommended rates increased yields of wheat grown on fallow and stubble by an average 12%. Total wheat production (kg/ha/yr) was inversely related to the frequency of fallow in the rotation. Continuous wheat (N and P applied) outproduced wheat grown on fallow in the 2-yr rotation by 53% over the 12-yr period.
1180. Campbell, C.A., R.P. Zentner and P.J. Johnson. 1988. Effect of crop rotation and fertilization on the quantitative relationship between spring wheat yields, available soil moisture, and precipitation.. Canadian J. Soil Sci., 68(1):1-16.
The effects of crop rotation and fertilization on the quantitative relationship between spring wheat yields, available soil moisture, and growing season precipitation were determined. Stubble-seeded wheat required 68 mm of moisture to produce the first kilogram per hectare of grain; fallow-seeded wheat required about 46mm. The lower threshold level of MU for grain production decreased from about 140mm to the values cited above; this has resulted in substantially greater moisture use efficiency in recent years likely due to better, more timely crop mangement and the improved cereal varieties.
1292. Chaudhary, T.H.. 1976. The effect of nitrogen source and 2-chloro-6-(trichloromethyl) pyridine (N-Serve) on the nitrogen and sulfur nutrition of wheat.. Ph.D. Thesis, Dept. of Agronomy and Soils, Washington State Univ., Pullman, WA.
The effects of urea applications with and without the product N-serve were examined. N-serve considerably reduced the loss of NH4+-N to organic transformations, and resulted in much higher amounts that were available to plants. Some problem of N toxicity resulted, but this was presumed to also be related to a lack of sulfur. T: Many. e.g.:Changes in the organic N content of the soil and N uptake by plants. Amounts of NH4+-N and NO3--N in the soil in April and August. Dry-matter yields and percentage uptake of N and S.
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.
2221. Goldstein, Walter A.. 1986. Alternative crops, rotations, and management systems for dryland farming.. Ph.D. dissertation, Agronomy and Soils, WSU.
This work covers a number of research areas, including the use of edible white lupine as an alternative crop, the use of black medic in rotation with spring peas and winter wheat (the PALS concept), performance of winter wheat as influenced by rotations, fertilization, and fumigation; rotational effects of medics; wheat interference with weeds; costs and returns of alternative systems; comparison of agronomic effects of conventional, organic, and biodynamic management. The PALS (perpetuating alternative legume system) concept was field-tested using a pea + medic - medic GM - winter wheat rotation with limited inputs of agrichemicals and tillage. This system was more economic using market prices of commodities at both a low and high yield level. With government support prices, the PALS system was competitive in the low yield situation, but not the high. Rotational effects appeared to suppress weeds in wheat with the medic compared to a continuous cereal system.
2385. Hammond, M.W. and D.J. Mulla. 1989. Field variation in soil fertility: its assessment and management for potato production.. Presentation at 28th annual WA Potato Conference.
Spatial variability in potato fields for P and K is common and can lead to yield and quality reductions. The potential for variable fertilizer application allows for an efficient solution to the problem, both from an economic and environmental standpoint. The paper presents an example from an irrigated circle in the Columbia Basin. Fertility maps of the field are presented, showing the spatial variability. This information is used to delineate fertility management zones, which receive different rates. Fertilizer efficiency is shown for both the conventional and variable methods. The variable method increased fertilizer costs about $10/ac. on a 200' grid system, where both P and K were mapped. The program will normally increase profits well beyond this expense.
2396. Hammond, M.W. and D.J. Mulla. 1989. Intensive soil sampling and its use in fertilizer programs.. Presentation at 1989 Irrigated Agr. Fertilizer Conference.
Intensive soil sampling on a small grid in farm fields allows one to determine the spatial variability of nutrient levels and to adjust fertilizer applications accordingly. Data from 100, 200, and 400 ft. grids indicates that results from a 200' grid are adequate, but detail is lost at 400'. Soil information can be put on a computer chip for a given field and then used to drive variable fertilizer and pesticide application equipment.