Micronutrient concentrations in barley and soybean under minimum tillage on Podzolic soils in a cool climate

Micronutrients can be limiting for crop production and quality in fine sandy loam Podzolic soils in the cool, humid climate of Atlantic Canada. This study was conducted to determine the effect of mimimum tillage practices, in three long-term animal feed crop rotations, on micronutrient (B, Cu, Zn, Mn, Fe and Mo) content and grain quality of spring barley (Hordeum vulgare L.) and soybean (Glycine max L. Merrill). Reductions in soil tillage had various effects on micronutrient concentration in plant parts, especially for Cu, Zn, Mn, and Mo, which were probably related to pH changes at the soil surface. Grain micronutrient concentrations, however, for crop yield potential tended to be in the sufficiency range and were not limiting for crop growth or feed quality. Evidence suggesting a decline in Mo concentration over time underlines the need for periodic assessment of micronutrient assimilation in conservation tillage systems.