15 research outputs found
Variability of soil salinity and nitrate within a saline area: consequences for soil testing and fertilizer response
Non-Peer ReviewedSoil test field calibration trials are most often established within apparently uniform, usually small, areas within fields. Results from many such sites over several years are then used to develop criteria for providing fertilizer recommendations based on analysis of samples representing entire fields, typically 40 to 160 acres. Implicit in this approach is an assumption that optimum fertilization for the field (if fertilization is not to be varied within the field) will be similar to optimum fertilization for the average soil condition (as determined by the soil analysis) present in field. The validity of this assumption should always be a concern in soil test interpretation; it becomes a major concern where a field soil test shows a sufficient test level of a nutrient which is expected to be highly variable within the field In those cases potentially large fertilizer response in deficient portions of the field may justify (economically) fertilization of the entire field. Soil salinity is known to be highly variable within fields, and to influence crop growth and soil residual nitrogen (N). This study examined the variation in levels of salinity and N present as nitrate (NO3-N) within a 40-acre saline stubble area, to assess the effectiveness of routine soil testing procedures for this situation. It is recognized that truly economic optimum fertilization cannot be achieved for variable fields unless the fertilizer applications are correspondingly varied within the fields. However, the objective of this study was to evaluate conventional soil testing and fertilization practices, rather than to develop a variable rate fertilization system
Soil micronutrient problems and research in western Canada
Non-Peer ReviewedMicronutrient deficiencies have been recorded in a few western Canadian soils. This paper reviews the published work on zinc, manganese, copper, iron, boron, and molybdenum in western Canadian soils and plants. Suggestions are made for procedures that could be employed by soil testing laboratories and research agencies to identify deficient soils
Crop responses to sulphur and micronutrients on selected soils of Saskatchewan
Non-Peer Reviewe
Responses to sulphur and micronutrient fertilization in Saskatchewan (1986-1988)
Non-Peer Reviewe
Microbial enzyme activity in irrigated canola plots receiving different nitrogen applications
Non-Peer Reviewe