Rice growth response to CRF fertilizer and biochar in rainfed land under two continuous seasons

Abstract

Rainfed rice productivity in Indonesia is generally lower than irrigated paddy fields. The low productivity is likelihood caused by poor soil fertility and low rainfall during the dry season. This research aims to determine the role of controlled release fertilizer (CRF) and rice husk biochar (RHB) for the rice growth in two continuous seasons. The experiment was a randomized complete block design with three replicates and plot size was 5m x 6m. In wet season (WS), rice planted under direct seeded system. In dry season (DS), the rice was transplanted from seed bed. RHB rates were 0, 5, 10 t ha−1, and CRF Urea (42% N) rates were 0, 50 and 100 % of recommended dosage or equal to 0;142.5; 285 kg/ha respectively. As a positive control was 100 % dosage of recommended NPK fertilizers, namely: urea (45% N) 266 kg/ha, SP36 125 kg/ha and KCl 100 kg/ha. Agronomic traits such as plant height, tiller number, leaf greenness under DS and WS increase significantly as treated with a combination of RHB and CRF, while the distribution of roots and N uptake only increases under DS as such. Optimal plant growth and N uptake in rainfed rice were obtained at treatment of 5 t ha−1 RHB and 50% CRF. Therefore, the dosage is recommendable for developing rice production in rainfed areas both in the dry and wet season.