Soil fertility and zinc application influences yield and zinc-iron nutrition in rice (Oryza sativa) under system of rice intensification and conventional methods

A field experiment was conducted during the winter (rabi) seasons of 2013–14 and 2014–15 in an Inceptisols of the Indo-gangetic plains of West Bengal, to evaluate the effect of soil-fertility levels and Zn application on yield, yield-attributing characters and Zn-Fe enrichment in the popularly grown rice (Oryza sativa L.) cultivars under system of rice intensification (SRI) and conventional method. The grain yield was found slightly higher (1.80% than SRI) under conventional system, while the straw yield was found higher under SRI (2.09% than the conventional system). Zinc application had profound influence on yield, yield-attributing characters and Zn content in different plant parts under both the systems. The increase in grain yield owing to zinc fertilization was more under conventional system (24.2, 25.4 and 26.9% at low, medium and high fertility levels respectively) than SRI. Zinc enrichment to the tune of 16.1% was observed owing to zinc fertilization but it significantly decreased 5.02% Fe content in the rice grain, indicating a phenomenon of possible Zn-Fe antagonism. Therefore, the conventional system was found superior to SRI so far yield, yield-attributing characters and Zn and Fe content in rice are concerned.