Browse on keywords: crop rotation OR
Search results on 05/22/13
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.
1819. Elliott, L.F. (ed.). 1987. STEEP - Conservation concepts and accomplishments.. Washington State Univ. Publ., 662pp..
A compilation of 48 papers covering: tillage and plant maagement; erosion and runoff predictions; plant design; pest management; socio-economic; integrated systems; technology transfer for cropping systems; 22 technical notes. T: many
2249. Granatstein, D., D. Bezdicek, L. Elliott, V. Cochran, and J. Hammel. 1987. Long-term tillage and rotation effects on soil microbial biomass, carbon, and nitrogen.. Biol. Fertil. Soils 5:265-270..
This research examined plots that had been under different tillage and rotational management for 12 years. Rotations were WP (winter wheat-spring pea); WBP (winter wheat-spring barley-spring pea); WPA (winter wheat-spring pea undersown with red clover and alfalfa)-clover/alfalfa GM). The two tillages studied were moldboard plowing and no-till. There was little difference in microbial biomass, C or N below 5 cm in the no-till, with surface values being highest. Few differences due to rotation could be detected. The WPA rotation had the highest total C and N. Microbial biomass was higher in no-till surface soils where the preceding crop had provided high residue, while the opposite was true for tilled plots. Microbial biomass levels changed little from April to September, and then jumped higher in October with the advent of moisture.
2406. Hanley, Paul (ed.). 1980. Earthcare: Ecological agriculture in Saskatchewan.. Earthcare Information Centre.
A well-written text covering all aspects of biological farming in the prairie region of Saskatchewan. Practices apply to small and large farms. Includes reports from selected farms. References at the end of chapters.
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
2735. Horner, G.M., M.M. Oveson, G.O. Baker, and W.W. Pawson.. 1960. Effect of cropping practices on yield, soil organic matter and erosion in the Pacific Northwest wheat region.. PNW Technical bulletin 1; USDA-ARS and Ag. Expt. Sta.'s of ID, OR, WA.
Summary of soil management experiments conducted over 40 yrs at six experiment stations. Covers: crop rotation, fertilization, and use of organic material. Some results: sweetclover and alfalfa were more effective than other legumes in increasing wheat yield. Yields of wheat were markedly affected by the sequences of cropping. Return of straw to soil decreased yields slightly under low N conditions. Organic and mineral N had no effect on yields in low precip. zones. Also covers runoff and erosion. T: many, eg.: effect of crop rotations on crop yield; crop yield as affected by grass/clover; effect of OM on wheat yield.
2928. Idaho Agr. Expt. Sta.. 1949. Annual report.. ID Agr. Expt. Sta. Bull. #276.
Sweetclover maintained OM levels, slight loss in W-P; N fertilizer reduced OM losses where straw was removed.
2995. Jacklin, A.W.. 1936. Crop rotations.. USDA-SCS Agronomy - Range Meetings, Pullman, WA #580.
Use legume grass mix in higher rainfall area, grasses in drier areas; rotations are typically 4-7 yr long; perennials can help check the weed problem; subsoiling effect of alfalfa, sweetclover reduces erosion and run-off; grass roots superior in soil aggregation.
3107. Dormaar, J.F. and C.W. Lindwall. 1989. Chemical differences in dark brown chernozemic Ap horizons under various conservation tillage systems.. Can. J. Soil Sci. 69:481-488.
Soil properties were investigated in two long-term studies: a 19 yr study of till vs. no-till in wheat fallow, and a 9 yr study of till vs. no-till with 3 rotations, including continuous cropping. No-till had the predominant influence on improving various soil physical and microbial properties. There was little difference in continuous cropping versus wheat-fallow, with tillage. The study compared soil from the entire plow depth, and concluded that 19 yr was long enough for the entire Ap horizon to benefit from no-till. No-till in both studies led to 40% of the dry aggregates being >0.84 mm. Dehydrogenase and phosphatase activities were twice as high under no-till as under cultivatiion. No-till also led to the largest monosaccharide accumulation in the soil.
3373. Janzen, H.H.. 1987. Soil organic matter characteristics after long-term cropping to various spring wheat rotations.. Can. J. Soil Sci., 67:845-856.
Various spring wheat rotations with and without perennial forages on total and mineralizable soil organic matter contents. The organic C and N contents of soil after 33 yr of cropping were highest in treatments continuous W and FWWAAA, and decreased with increasing frequency of fallow in the rotation. The inclusion of the perennial forage in the rotation did not increase organic C and N levels above those abserved in the continuous wheat treatment. It was concluded that inclusion of perennial forages in spring wheat rotations for the purpose of enhancing soil fertility and organic matter levles was not justified under semi-arid conditions.