The effect of biofertilizer on increasing upland rice yield in rainfed rice field in boyolali

The low availability of nutrients is an obstacle to increasing rice productivity in rainfed rice fields. The application of a combination of biofertilizers and inorganic fertilizers was known to increase the efficiency of using inorganic fertilizers. This study aims to determine the effect of biofertilizers on the growth and yield of rice plants in a rainfed rice field. The study was conducted on rainfed rice fields in Banyusri Village, Wonosegoro District, Boyolali Regency from September to December 2013. A total of 6 biofertilizer products were used in this study, namely PR, RC, ST, AGR, BV and GLK. The rice variety used was Situ Patenggang. The study used a randomized block design with 9 treatments and each treatment was repeated 4 times. The nine treatments were: fertilization according to the recommendations of dry soil test device (P1); ½ dose of P1 (P2); P2 + manure (P3); P2 + PR (P4); P2 + RC (P5); P2 + ST (P6); P2+AGR (P7); P2+BV (P8); P2+GLK (P9). Planting using a 2:1 jajar legowo system with a spacing of 20 x 10 x 40 cm was carried out by direct planting of 4-5 seeds per hole. Biofertilizer application is carried out according to the instructions of each product. Parameters observed included: soil chemical status (N, P, K, C-organic, pH, CEC) before the study; plant growth (plant height, number of tillers and number of productive tillers); yield (weight of harvested dry grain and dry milled); and a simple farming analysis was carried out. The results showed that all combinations of biofertilizers with ½ recommended dose were effective in increasing rice yields but they could not match the yield of rice fertilized according to the recommended dose. The combination of fertilization using GLK biofertilizer showed the highest yield compared to other biofertilizers with an advantage of 48.05% compared to ½ recommended dose of fertilization.