• Authors:
    • Zentner, R. P.
    • Campbell, C. A.
  • Source: Soil Science Society of America Journal
  • Volume: 57
  • Issue: 4
  • Year: 1993
  • Summary: Few studies conducted in western Canada have assessed how crop rotations and fertilization influence soil organic matter content on land that has been cropped for many years. We monitored soil organic matter in the 0- to 0.15- and 0.15- to 0.3-m depths of a 24-yr crop rotation experiment conducted on a medium-textured Aridic Haploboroll in southwestern Saskatchewan. Prior to the study, the land had been in a hard red spring wheat (Triticum aestivum L.)-fallow rotation for {approx}50 yr. Only the 0- to 0.15-m segment showed significant treatment effects. Due to good weather and crop yields in the first 15 yr, soil organic matter had increased under well-fertilized annually cropped rotations, and it remained constant under fallow-containing rotations and under continuous wheat receiving inadequate N fertilizer. Because of several dry years in the final 9 yr of the study, all rotations except a well-fertilized, fallow-winter cereal-wheat system lost organic matter. Changes in organic matter were directly related to the amount of crop residues produced by these systems and their ease of eroding. Soil organic matter was inversely related to apparent N deficit (i.e., N exported in grain minus N applied as fertilizer). The fallow-flax (Linum usitatissimum L.)-wheat rotation receiving N and P fertilizer had the lowest soil organic matter, partly due to low production of crop residues by flax, partly to greater leaching of NO3, and partly due to some loss of flax residues blown from the plots. Soil organic matter in the well-fertilized fallow-winter cereal-wheat rotation remained constant because its shorter fallow period reduced soil erosion, and due to its more efficient use of N, as evidenced by minimal leached NO3-N.
  • Authors:
    • Anderson, G. W.
    • Shaw, J. E.
    • Swanton, C. J.
    • Eadie, A. G.
  • Source: Weed Technology
  • Volume: 6
  • Issue: 3
  • Year: 1992
  • Summary: The acceptance of no-till crop production systems has been limited due to expected problems with weed management. Field experiments were established at two locations in Ontario in 1988 and one location in 1989. Band or broadcast applications of preemergence (PRE) combinations of high or low label rates of atrazine with or without metolachlor or inter-row cultivation, were evaluated for their effectiveness in controlling annual weeds in no-till corn. At each location, different herbicide and cultivation combinations were required to achieve adequate weed control. Corn grain yield was equivalent regardless of whether herbicides were applied as a band or broadcast treatment at all three sites. At two of the three sites, one cultivation combined with herbicides applied as a band was adequate to maintain weed control and corn grain yields. Selective application of herbicides in bands represented an approximate 60% reduction in total herbicide applied into the environment. The integration of a shallow post-plant inter-row cultivation combined with the soil conservation attributes of no-till, would enhance the sustainability of a modified no-till corn production system.
  • Authors:
    • Weise, S. F.
    • Swanton, C. J.
  • Source: Weed Technology
  • Volume: 5
  • Issue: 3
  • Year: 1991
  • Summary: A growing awareness of environmental issues in Canada has had a major influence on government policies. An initiative was launched by the government of Ontario to promote research toward the development of an integrated weed management (IWM) system. Research in IWM must take all aspects of the cropping system into consideration and evolve in a progressive manner. This approach must encompass the role of conservation tillage, knowledge of the critical period of weed interference, alternative methods of weed control, enhancement of crop competitiveness, modeling of crop-weed interference, influence of crop rotation and seed bank dynamics, and education and extension of the findings. The complexity involved in addressing these issues requires a multi-disciplinary approach.
  • Authors:
    • Lafond, G. P.
    • Zentner, R. P.
    • Biederbeck, V. O.
    • Campbell, C. A.
  • Source: Canadian Journal of Soil Science
  • Volume: 71
  • Issue: 3
  • Year: 1991
  • Summary: The effects of crop rotations and various cultural practices on soil organic matter quantity and quality in a Rego, Black Chernozem with a thin A horizon were determined in a long-term study at Indian Head, Saskatchewan. Variables examined included: fertilization, cropping frequency, green manuring, and inclusion of grass Jegume hay crop in predominantly spring wheat (Triticum aestiyum L.) production systems. Generally, fertilizer increased soil organic C and microbial biomass in continuous wheat cropping but not in fallow-wheat or fallow-wheat-wheat rotations. Soil organic C, C mineralization (respiration) and microbial biomass C and N increased (especially in the 7.5- to l5-cm depth) with increasing frequency of cropping and with the inclusion of legumes as green manure or hay crop in the rotation. The influence of treatments on soil microbial biomass C (BC) was less pronounced than on microbial biomass N. Carbon mineralization was a good index for delineating treatment effects. Analysis of the microbial biomass C/N ratio indicated that the microbial suite may have been modified by the treatments that increased soil organic matter significantly. The treatments had no effect on specific respiratory activity (CO2-C/BC). However, it appeared that the microbial activity, in terms of respiration, was greater for systems with smaller microbial biomass. Changes in amount and quality of the soil organic matter were associated with estimated amount and C and N content of plant residues returned to the soil.
  • Authors:
    • Miller, M.
    • O'Halloran, I.
    • Arnold, G.
  • Source: Canadian Journal of Soil Science
  • Volume: 66
  • Issue: 2
  • Year: 1986
  • Summary: In 1981, phosphorus absorption by young corn plants was greater from no-till than from plowed plots with similar NaHCO 3-extractable P (Ext P) concentrations. A series of growth room studies was conducted to explain this difference. Corn plants grown on cores from the no-till plots had a higher P concentration than plants grown on soil from the plowed plots, in spite of a lower root growth and a lower Ext P content. Disturbance of the no-till soil eliminated the effect. A parameter, accessible P (Acc-P), was calculated from root length and Ext P assuming P was absorbed from a cylinder of soil around each root. Shoot P content at a given Acc-P content was always higher with the undisturbed no-till soil than with either the disturbed no-till or the plowed soil. Irradiation (gamma-ray) of the no-till soil reduced P absorption by a similar degree to disturbance, indicating that a biological factor was involved. Disturbance of soil had no influence on P content of canola ( Brassica napus L.), a nonmycorrhizal crop. Soil disturbance reduced the intensity of mycorrhizal infection in corn roots. It is hypothesized that disturbance of the no-till soil reduced P absorption by reducing the effectiveness of the mycorrhizal symbiosis.
  • Authors:
    • Sommerfeldt, T. G.
    • Freeze, B. S.
  • Source: Canadian Journal of Soil Science
  • Volume: 65
  • Issue: 4
  • Year: 1985
  • Summary: The economics of hauling manure as a substitute for commercial fertilizer in the production of cultivated crops was investigated using a computer model that accommodates variables such as hauling distance, machinery complement, hauling speed, labor use, spreading time, and crop response. Machinery complement and labor requirements were defined and budgeted for three farm-feedlot scenarios, namely: a very large farm-feedlot (> 1000 head capacity), a large farm-feedlot (500–1000 head capacity), and a small farm-feedlot (< 500 head capacity). Results indicate that manure, valued for its N and P2O5 nutrient content, is generally an economical substitute for commercial fertilizer when hauled up to 15 km from feedlot sources. Large farm-feedlots, hauling manure less frequently and employing a farm tractor with front-end loader and single axle truck with a manure box, can haul manure up to 15 km and recover all costs. Small farm-feedlots employing a farm tractor with front-end loader and pull-type manure spreader can economically haul manure up to 15 km if non-cash costs and labor charges are disregarded. Alternatively, custom corral cleaners can be hired to haul manure up to 18 km in competition with commercial fertilizer on an N and P2O5 nutrient value basis. The yield benefits of manure increased the breakeven hauling distances dramatically for some crops. A need for more research to determine economic optimum manure application rates for various crops is identified. Key words: Fertilizer, feedlot manure, fertilizer economics, animal wastes