Use of Biofilm Biofertilizer for Rice Cultivation in Anuradhapura, Sri Lanka: A Case Study

Abstract

Combined application of biofilm biofertizers (BFBFs) and 65% of Department of Agriculture (DOA) recommended chemical fertilizers (CF) showed higher rice grain yields in several districts of Sri Lanka i.e. Plonnaruwa, Amapra and Mahiyanganaya but no reported indications in Anuardhapura. Therefore, present study was undertaken to test the potential of BFBFs (Biofilm –R) for rice in Anuradhapura. A field experiment was conducted in a farmer field at Nachchaduwa which belongs to Anuradhapura district in later of Dry (Yala) season 2021. The treatment of 100% CF mixture recommended by the DOA was tested against the reduced dosage CF (65% DOA CF)+ BFBF-R recommended by the National Institute of Fundamental Studies (NIFS) for the biofilm application. Soil alone without amendments was served as the control. All treatments were replicated three times and arranged in a Completely Randomized Block Design (RCBD) in fields. The basic soil characteristics were analyzed prior to initiate the field trial with the rice variety of BG 352. After 14 weeks at the harvest, root and shoot dry mass, panicle length and plant heights were measured as plant growth parameters.   Final grain yield and certain soil parameters (soil pH and microbial biomass C) were analyzed. Results of the field trial, revealed that the BFBF-R added NIFS recommendation showed no significance effect against the 100% DOA CF in root dry mass, plant height and panicle lengths while 100% DOA CF recorded significantly highest shoot dry mass at harvest. The most prominent results for final grain yield was also recoded with 100% DOA CF compared to BFBF-R added NIFS recommendation by showing the higher nutrient releasing capacity of CF full dosage (100%) rather than the reduced dosage (65%) even coupled with the biofilms. However, 65% DOA CF+ BFBF-R significantly contributed to enhanced soil microbial community compared to other treatments reflected by the elevated microbial biomass C content at the harvest. Overall, it can be conclude that; Biofilm added NIFS recommendation showed no added advantage over the full dosage of DOA recommendation to rice grain yield for selected filed in Nachchaduwa but significantly contributed to enhanced soil quality, compared to other treatments. Therefore, further studies are needed to optimize CF rate to be coupled with BFBF to get an acceptable rice grain yield.