Influence of moisture and temperature on soil micronutrient supply, uptake and biomass yield of wheat, pea, and canola

Abstract

It is not always easy to predict the crop yield response to micronutrient fertilization particularly under unfavorable environmental conditions as these may alter both crop demand and the ability of the soil to supply micronutrient to plant roots. The objective of this research was to evaluate the effect of temperature and moisture and their interaction on crop growth response, micronutrient supply during growth and effects on amounts and distribution of micronutrient among fractions in the soil after harvest. Brown and Dark Brown soils collected from farm fields in southern Saskatchewan were used in which wheat, pea, and canola were grown in controlled environment chambers. The biomass yields of wheat, peas, and canola were decreased with cold temperature and moisture stress (drought and waterlogged) soil conditions. Significantly increased plant uptake of Cu, Zn, and B was associated with optimum (field capacity) soil mo isture and warm temperature (23 C) growing conditions compared to drought (50% field capacity), waterlogged, and cold (5 C) temperature conditions. Environmental stress had the greatest impact on pea, reducing crop growth and micronutrient utilization efficiency. Soil supplies of Cu and Zn were most negatively impacted by drought stress, which was attributed to the negative effect of reduced soil moisture on movement by diffusion. The extractable soil available micronutrients and chemical speciation conducted on dried soil samples collected post-harvest indicated little difference among moisture and temperature treatments, and that the bioavailability and transformation of micronutrients were not affected by short-term environmental stress crop growth conditions. However, it is suggested that if possible, assessments of micronutrient forms also be conducted on soil samples under the actual moisture and temperature conditions as they exist in the experiment, as well as on dried, processed samples.