Browse on keywords: organic matter Alberta
Search results on 06/19/13
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.
6592. Sommerfeldt, T.G., C. Chang, and T. Entz. 1988. Long-term annual manure applications increase soil organic matter and nitrogen, and decrease carbon to nitrogen ratio.. Soil Sci. Soc. Am. J. 52:1668-1672.
Studied the effects of long-term annual additions of cattle feedlot manure on the accumulation, decomposition, and movement of organic matter and total N. Significant increases in SOM and total N in the first 8 and 6 yr, repsectively, were limited to the surface 30 cm of soil of both the nonirrigated and irrigated land, and were similar on both fields. Tillage did not affect the amount of accumulation. The rates of accumulation decrease with years of application such that after two or three decades, increases will be small. A model was developed to predict changes and develop guidelines for land disposal of feedlot manure.
8867. Dormaar, J.F., C.W. Lindwall, and G.C. Kozub. 1988. Effectiveness of manure and comercial fertilizer in restoring productivity of an artificially eroded dark brown chernozem soil under dryland condition. Can. J. Soil Sci. 68:669-679.
An artificially eroded field was not significantly improved for grain production by 21 yr of cropping without nutrient application. A subsequent wheat-fallow system was used for 5 yr either with additions of 13 T/ac feedlot manure or commercial fertilizer (60 lb N/ac, 30 lb P/ac). Both treatments restored productivity within the first year, as measured by wheat yield. During drought years, manure plots consistently yielded more than fertilized plots. Manure significantly increased the organic matter, total N, available P, and water-stable aggregate status of the soil.