Requirement of micronutrients for sustainable Crop yield in the rice-rice pattern in old Brahmaputra floodplain soil

Abstract

An experiment was conducted at Soil Science Field Laboratory of BAU farm, Mymensingh during February to November 2011 with an objective of determining the requirement of micronutrient(s) for achieving the maximum yield of crops in the rice-rice pattern. The experiment was designed with seven treatments, laid out in a randomized complete block design (RCBD) with three replications. The treatments were T1: control, T2: Zn, T3: Zn+B, T4: Zn+B+Cu, T5: Zn+B+Cu+Mn, T6: Zn+B+Cu+Mn+Fe and T7: Zn+B+Cu+Mn+Fe+Mo. These treatments were applied to Boro rice (BRRI dhan29), and the T. Aman rice (BINA dhan7) was grown on the same plots after harvesting of Boro rice, with no further addition of any micronutrient. For both Boro and T. Aman rice, nutrients such as N, P, K and S were added to all plots as per recommendation. There was a significant effect of micronutrients on the yield of Boro rice and their residual effect on T. Aman rice. Among the micronutrients, the effect of Zn, B and Cu was prominent. The addition of Zn, Zn+B and Zn+B+Cu to Boro rice resulted in a 10, 20 and 24% yield increase over control treatment, respectively. The added micronutrients also showed significant effect on the yield parameters viz. tillers hill, grains panicle and 1000- grain weight of the crops. Micronutrient concentrations and uptake by Boro rice were also significantly influenced by the added micronutrients. Overall results suggest that the combined application of Zn, B and Cu along with NPKS is necessary to ensure yield maximization of crops in a rice-rice sequence in Old Brahmaputra Floodplain soil (AEZ 9). This study should be extended across the country to delineate micronutrient deficiency of soils and crops so as to ensure efficient fertilizer management for achieving higher and sustainable crop yield.