Pemanfaatan Biochar Kulit Buah Kakao dan Sekam Padi untuk Meningkatkan Produktivitas Padi Sawah di Ultisol Lampung

Abstract

Utilization of Biochar of Cocoa Shell and Rice Husk to Increase Rice Productivity in Ultisol Lampung. Biochar application as soil amendment is technology for soil and crop productivity improvement in acid soil. The main problem of acid soil including in paddy field is high concentration of Al3+ that inhibit crops growth causing low crop production. The objective of this study was to evaluate the effects of cocoa shell and rice husk biochar on paddyfield productivity and soil chemical properties. The study was conducted at Agricultural Research Station of Tamanbogo, East Lampung on June-September 2012 (planting season 1), January-April 2013 (planting season 2) and December 2013-March 2014 (planting season 3). The experimental design was split plot design, which the main plotswere two types of biochar (cacao shell and rice husk), the sub plots were biochar rates 0.5 t/ha (control), 5 t/ha and 15 t/ha with five replications. The parameters measured were paddy growth, yield and soil chemical properties (soil pH,C organic, N total, available P, K total, and Al3+ ). The result showed that biochar could affect weight of rice straw andrice yield at the second and third planting season, while biochar rates could affect crop growth and yield of rice at three planting. The effect of cacao shell and rice husk biochar application with the rate of 15 t/ha could up to three planting seasons without any biochar addition in following two consecutives year, whereas addition biochar 5 t/ha wasless effective. The cacao shell biochar was more effective in increasing crop growth and yield than rice husk biochar,as seen on dry grain rice yield, i.e. 3.58 t/ha (PS1) and 5.06 t/ha (PS III). During two planting seasons, both biochar at the rate of 15 t/ha were sufficient to improve soil chemical properties. Cacao shell biochar with the rate of 15 t/ha had better effect in improving soil chemical properties significantly in term of soil pH, available P, and total K content and decreasing aluminum content than rice husk biochar especially at second planting season