More information on the transformation and availability of micronutrients for different soils and the effect of
manipulating the soil physical environment and its moisture regimes on plant available micronutrients need to be
generated. Continuous use of farmyard manure or of other organic sources arrests the depletion of available micronutrient
pools from soils. Development of integrated micronutrient technology using available organic materials
is needed not only to increase micronutrient use efficiency but also to decrease the pressure on the use of
costly inorganic micronutrient carriers. Field experiments have proved the superiority of zinc sulfate as a zinc
carrier. Increasing costs coupled with a shortfall in supply of zinc sulfate have necessitated investigations on
evaluating sparingly soluble zinc sources or ores combined with zinc mobilizers. The residual availability of
various sources of micronutrients for a cropping system needs to be worked out.