Micronutrient deficiencies are becoming serious because of escalated nutrient demand from more intensive and exploitative agricuiture, coupled with use of single-nutrient fertilizers and low amounts of organic manures. In rice ecosystems, crop residue management by recycling wastes and manures is the prime factor that controls the long-term micronutrient balance of the soil. Micronutrient cycling in soils is closely associated with organic matter turnover because it is intricately related with trace elements. Green manures, being succulent and fast degrading under submerged condition, might act as effective electron acceptor and this property rriay influence the chemical reduction of all metallic cations thereby favouring the utilization of nutrients in general and Zn in particular, by rice. Keeping these points in view, the literature pertaining to the beneficial effects of added zinc either in the presence or absence of green manure on rice yield, Zn availability in soil and its uptake by rice for establishing integrated nutrient supply system in lowland rice have been reviewed.
