Managing zinc deficiency in transplanted flooded rice by nursery enrichment

Zinc deficiency in flooded rice (Oryza sativa L,) requires developing inexp ensive and practically adoptable technologies for managing the disorder on a worldwide basis. Dipping nursery roots in ZnO slurry, despite being econo mical, has never been adopted by the growers, primarily because of the heav y labour requirement. The present investigation, involving greenhouse and f ield experiments, compared a number of management practices aimed at allevi ating Zn deficiency in transplanted flooded rice (cv. IR-6) grown in alkali ne soils. Three alternate methods tried, i.e., nursery root dipping in ZnSO 4 solution or ZnO slurry, and Zn-enriched nursery, proved equally effective of superior to the conventional ZnSO4 field-broadcast method. Contrary to earlier belief, Zn enrichment of nursery proved very effective even in seve rly Zn-deficient soils. Since the nursery area to be fertilized was far les s than the field area, value:cost ratio (VCR) of the nursery enrichment was far better than the ZnSO4 field-broadcast. Moreover, Zn application to nur sery beds was much easier compared to its broadcast in puddled fields. Ther efore, considering the effectiveness, economy, and farmer-adoptability, see dling enrichment by ZnSO4 application to nursery beds at 20 kg Zn ha(-1) is recommended to rice growers.