Wheat Grain Nutrient Content As Affected by Nutrient Availability In Soils.

The mineral nutrients in the harvested portion of a wheat crop originate from the soil along with any added nutrient source such as fertilizer or bio-solids. In most cropping systems if fertilizers are added to the soil only three or four mineral nutrients are added, for example nitrogen, phosphorus, potassium and sulfur. However there are all the other ten mineral nutrients that are taken up by crop roots that are used by the plant and a portion of total uptake of these nutrients are translocated to the grain. This presentation will report the results of a study comparing plant available nutrients in the soil, as measured by soil analysis before planting, to the concentration of those nutrients in the harvested grain of wheat. The study design consisted of ten different wheat genotypes (five bread wheat , three durum and two feed cultivars) grown at six different locations in southern Saskatchewan (three sites) and southern Alberta (three sites), during the growing season of 2010. The correlation between soil test nutrient availability level and nutrient content of the harvested grain was different for each nutrient. Some grain nutrient contents were significantly correlated to availability in the soil, while others were not. It appears that some nutrient concentrations in the grain stay within a certain range of concentration whether or not availability on the soil is in excess to crop needs or not, while other nutrients will be in higher in concentration if availability is greater. This has been called luxury consumption.