Effect of variability of zinc on enhancement of zinc density in basmati rice grain grown in three different soils in India

Abstract

Initially, a preliminary study was conducted to assess the variation of grain zinc (Zn) and iron (Fe) content of 10 basmati rice cultivars. Thereafter, comprehensive study was conducted to enhance the Zn density in grain using three cultivars (CSR 30, Pusa Basmati-6 and PusaSugandh 5) selected from the preliminary study, using three diverse soil types ((Inceptisols of IARI, New Delhi; Inceptisols of farmer’s field, Karnal; and Alfisols of CRIDA, Hyderabad) and six zinc nutrient management treatments including control. The results in the preliminary study indicated that the Zn content in rice grain (after hulling) varied from 13.3 to 22.5 mg kg−1 with mean of 18.8 mg kg−1, while Fe content varied from 8.3 to 14.3 mg kg−1 with mean of 10.7 mg kg−1. In the comprehensive study, the highest Zn content in grain (21.2 mg kg−1) and straw (33.2 mg kg−1) was observed in CSR-30 Cultivar. Among the soil types, Alfisols of CRIDA, Hyderabad maintained significantly highest Zn content in grains and straw. Among the Zn containing nutrient management treatments, application of 5 mg Zn kg−1 (basal) + foliar spray of 0.5% ZnSO4 (bi-weekly) maintained significantly highest Zn content in grain (21.9 mg kg−1) and straw (41.3 mg kg−1). Further, based on the assumption that when an individual consumes rice @ 200 g day−1, his daily dietary intake of Zn would be 3.53 mg day−1 in control (without Zn application) as compared to 4.38 mg day−1 with the rice grown with soil and foliage application of Zn.