Browse on keywords: crop rotation Saskatchewan
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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.
1172. Campbell, C.A., K. Bowren, G. LaFond, H. Janzen, and R.P. Zentner. 1989. Effect of crop rotations on soi organic matter in two black chernozems.. Soil and Crop Workshop, Univ. Saskatchewan, Saskatoon, Feb. 1989.
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.
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.
7761. Zentner, R.P., E.D. Spratt, H. Reisdorf and C.A. Campbell. 1987. Effect of crop rotation and N and P fertilizer on yields of spring wheat grown on a black chernozemic clay.. Can. J. Plant Sci., 67:965-982.
Including grass-legume forage, or legume green manure crops in the rotation increased yields of wheat grown on the unfertilized partial fallow by 15-24% and on unfertilized stubble by 33-71%; the yields were similar and sometimes higher than those obtained on fallow in the well-fertilized monoculture wheat rotations. Yields of fallow- and stubble-wheat were generally maintained over time with the application of recommended rates of N and P fertilizers, or by inclusion of legume-forage crops in the rotation, but yields of unfertilized stubble-wheat declined with time possibly reflecting declining soil fertility.
7770. Zentner, R.P., M.A. Stumborg, and C.A. Campbell. 1989. Effect of crop rotations and fertilization on energy balance in typical production systems on the Canadian prairies.. Agric., Ecosys., Environ. 25:217-232.
Non-renewable energy inputs, metabolizable energy output, and the energy efficiency of 10 spring wheat rotations were examined over 18 yr. Conventional tillage was used. Results showed total energy input per unit of land was lowest for the traditional wheat-fallow rotation (3482 MJ/ha), intermediate for N and P fertilized fallow-wheat-wheat (4470 MJ/ha), and highest for fertilized continuous wheat (7100 MJ/ha). Fuel accounted for 30-50% of the energy inputs, and fertilizer accounted for 15-49%. Pesticides were only 4-11%. Energy output to input ratios and the quantity of wheat per unit of energy decreased with cropping intensity. The average energy O/I was: F-W 3.6, F-W-W 3.3, cont. W 2.6. Rotations that included flax or cereal forage crops had the lowest energy efficiency.
10475. Campbell, C.A., G.P. LaFond, A.J. Leyshon, R.P. Zentner, and H.H. Janzen. 1991. Effect of cropping practices on the initial potential rate of N mineralization in a thin Black Chernozem.. Can. J. Soil Sci 71:43-53.
Potentially mineralizable N (No) was examined as a possible indicator of soil organic matter change due to management, using soil from 30 yr rotation plots near Indianhead, Saskatchewan. A parameter called the initial potential rate of N mineralization (No x rate constant k at time =0) was effective in distinguishing both the absolute and qualitative changes in soil organic N due to various management practices. The results showed that fertilizers can be as effective as legumes, used either for green manure or hay, in increasing the quantity and improving the quality of soil organic matter. Organic matter changes were similar between a 6 yr soil-building rotation and fertilized continuous wheat, but higher than unfertilized continuous wheat.
10756. Laird, E.. 1988. Grain legume mixtures and intercropping.. Proc. Crop diversification in sustainable agriculture systems, Univ. Sask., Saskatoon, p. 20-25.
The experience of several Saskatchewan farmers with intercropping is discussed. Some examples are durum wheat and flax, spring wheat and fall rye, rye and oats, rye and flax, peas and oats, mustard and peas, clover and oats. With wheat and rye, seeded together in the spring, the wheat is harvested the first year and the rye the next year. The rye discourages broadleaf weeds.
10786. Biederbeck, V.O.. 1988. Replacing fallow with annual legumes for plowdown or feed.. Proc. Crop diversification in sustainable agriculture systems, Univ. Sask., Saskatoon. p. 46-51.
Saskatchewan researchers tested several legumes as possible fallow replacements. Inoculation greatly improved growth and water use efficiency of the legumes, with an average of 2000 lb/ac dry matter and water use efficiency of 1490 lb H2O/lb DM. Legumes fixed an average of 44 lb N/ac. Chickling vetch performed the best, but since wheat yields were similar after all species, Indianhead lentil proved to be the most economic choice.