Browse on keywords: crop rotation Alberta
Search results on 05/18/13
144. Alberta Agriculture. 1984. Canola production survey results.. Field Crops Branch, Lacombe, Alberta, CANADA.
72% of the producers grew canola on stubble, while 28% followed summerfallow. Average yields were higher (2 bu/ac) where canola had not been grown in the past 4 years. Yields were not greatly affected by N rates from 10-120 lb/ac on summerfallow. Yields were slightly lower overall on stubble, and a steady response to N was noted. The top producers on summerfallow applied more of the N in the fall, and more of it was deep banded. Half of the top producers applied 30 lb/ac P2O5, while few applied K. Treflan was the most widely used herbicide. Few insect problems were reported, while many growers reported disease, but not at economic levels. Yields were in the 25-30 bu/ac range.
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.
8512. Izaurralde, R.C., N.C. Juma, and W.B. McGill. 1990. Plant and nitrogen yield of barley-field pea intercrop in cryoboreal-subhumid central Alberta.. Agronomy J. 82:295-301.
There was an advantage to intercropping barley and field peas for nitrogen efficiency, but not for plant yield. Barley-pea intercrops, each species seeded at half its sole rate, appear to increase N production in grain and straw over sole cropping under these climate and soil conditions.
10576. Janzen, H.H. and G.D. Radder. 1989. Nitrogen mineralization in a green manure amended soil as influenced by cropping history and subsequent crop.. Plant Soil 120:125-131.
In a greenhouse study, surface soil from long-term experimental spring wheat rotations was amended with 15N labelled legume green manure and subsequently cropped (canola and spring wheat) or incubated. N mineralization from both the indigenous soil N and from green manure was suppressed in cropped soil. Net N mineralization in the uncropped and cropped treatments averaged 73 and 43 mg/kg, respectively. This difference was attributed in part to enhanced biological immobilization in the rhizosphere. These data suggest that short-term N mineralization is favored by fallowing soil after green manure application whereas N retention in organic matter is favored by immediate cropping.