Integrated nutrient management for lowland rice (Oryza sativa L.) in the Anuradhapura district of Sri Lanka

Abstract

The impact of integration of inorganic fertilizer and organic manures on yield of rice (Oryza sativa L.) was evaluated under field conditions over two seasons. The experiment was laid out in a split-plot design with three replicates. The main plots were two rice varieties namely, Kaluheenati and Bg 352, and the sub-plots consisted of five fertilizer/manure combinations viz. T1 - control (without fertilizer and organic manure), T2 - 100% of fertilizer recommendation of the Department of Agriculture (DOA), T3 - 50% of fertilizer recommendation of the DOA, T4 - organic manure alone, T5 - 50% of fertilizer recommendation of the DOA + T4. The variety effect, fertilizer/manure combination effect and interaction effect of variety and fertilizer/manure combination on yield were significant (p<0.05). In Kaluheenati, organic manure (T4) was the most suitable for higher yield. The variety Bg 352 responded positively to organic manures in combination with inorganic fertilizers, which illustrates the possibility of substituting a part of inorganic fertilizers with organic manures (T5) saving 130, 43 and 37 kg urea, Triple Super Phosphate and Muriate of Potash/ha, respectively.