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 Cana da. This study was conducted to determine the effect of mimimum tillag e practices, in three long-term animal feed crop rotations, on micronu trient (B, Cu, Zn, Mn, Fe and Mo) content and grain quality of spring barley (Hordeum vulgare L.) and soybean (Glycine max L. Merrill). Redu ctions in soil tillage had various effects on micronutrient concentrat ion in plant parts, especially for Cu, Zn, Mn, and Mo, which were prob ably related to pH changes at the soil surface. Grain micronutrient co ncentrations, however, for crop yield potential tended to be in the su fficiency range and were not limiting for crop growth or feed quality. Evidence suggesting a decline in Mo concentration over time underline s the need for periodic assessment of micronutrient assimilation in co nservation tillage systems.