Browse on keywords: fertility K
Search results on 12/22/13
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.
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.
1657. Doughty, J.L., F.D. Cook, and F.G. Warder. 1954. Effect of cultivation on the organic matter and nitrogen of brown soils.. Canadian J. Agr. Sci. 34:406-411.
Over 14 yr of cropping, soils lost 26% of OM and 33% of total N. Only part of the N loss is accounted for by crop removal. Some N is lost by leaching, also some gaseous loss of N other than as ammonia.
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.
2809. Hume, L.. 1982. The long-term effects of fertilizer application and three rotations on weed communities in wheat.. Can. J. Plant Sci., 62:741-750.
The effect of fertilizer application and three rotations (continuous cropping, fallow-wheat, and fallow-wheat-wheat rotations)on the species composition of the weed community was examined using rotations that had been running for 21-22 yrs. Fertilizer application tended to reduce community differences between continuous cropping and short-term wheat-fallow rotations. With the use of 2- or 3-yr wheat-fallow rotations and herbicide application, weed problems can be minimized in southeastern Saskatchewan.
4077. Mason, J.L. and J.E. Miltimore. 1959. Increase in yield and protein content of native bluebunch wheatgrass from nitrogen fertilization.. Canadian J. Plant Sci. 39:501-504.
Native bluebunch wheatgrass in Okanagan Valley (11" precip.) showed marked response to nitrogen fertilization. Dry matter production doubled with 60N added as ammonium nitrate, protein increased from 3.9 to 6.2 %. Fertilizer also increased ground cover by the desirable grasses.
6647. Steel, S. and D. Smith. 1990. Farming from the ground down.. Farm Journal (mid-January).
Discusses Terry Holsapple farming system in Illinois. Both P and K levels have risen several years after the last application of commercial fertilizer.