Interaction effects of phosphorus and zinc on yield and nutritional quality of rice (Oryza sativa)

Abstract

A field experiment was conducted at Nadia, West Bengal, to evaluate the effect of different levels of phosphorus (P) and zinc (Zn) on the yield, soil P and Zn availability, P and Zn nutritional quality and also Zn recovery efficiency of boro rice (Oryza sativa). Combined application P and Zn enhanced increased the yield of rice, recording the highest in P80Zn10 treatment (P @ 80 kg/ha and Zn @ 10 kg/ha). Results showed significant increase in P : Zn ratio, grain phytic acid (PA) content and PA : Zn molar ratio with simultaneous decrease in Zn content and uptake by rice, Zn harvest index (Zn-HI), relative transfer of Zn from root to grain and also soil phosphatase activity (PA) in rice with P application up to the highest level (80 kg P/ha). The availability of applied Zn in soil was also reduced to some extent with higher rates of P application. However, Zn application significantly increased Zn content and uptake by rice and reduced the P : Zn ratio, grain PA content and PA : Zn ratio and ultimately enhanced the bioavailability of zinc in rice grains