Pengelolaan hayati tanah untuk meningkatkan peran fauna tanah dalam proses dekomposisi jerami padi pada budidaya System of Rice Intensification (SRI) di Kecamatan Cibungbulang, Kabupaten Bogor

Abstract

Recently, low agricultural production is becoming a main problem in agricultural sector in Indonesia, especially for food crop. System of Rice Intensification (S.R.I.) is a method of rice cultivation which is able to increase crop yield through soil, crop and water management system. The principles of the S.R.I. technique include planting of young and single seedlings with shallow-root planting, wide spacing and maintain unflooded soil condition with intermittent irrigation. Soil biological management can be applied to support the creating of more conducive environment for improving population and role of soil fauna, especially on organic matter decomposition. Modification of bund distance in rice field is one of those methods. This research aimed to study the effect of bund distance (4 meters and 8 meters) on the role of soil fauna in rice straw decomposition in S.R.I. cultivation technique by using litterbag method. The research was conducted in NOSC (Nagrak Organic S.R.I. Center) field in Cijujung Village, Cibungbulang Subdistrict, Bogor Regency. This research was designed according to bund distance treatment, two levels (short, 4 meters and long, 8 meters) and four replications. Measurement of the decomposition rate of rice straw performed by using litterbag in coarse mesh (10 mm), medium mesh (0.25 mm) and fine mesh (0.038 mm), which contained 10 g rice straw per litterbag. These litterbags were exposured to the rice field with humid soil condition and retrieved after 30, 60 and 90 days. Decomposition rate was measured by counting the difference weight of before and after exposure time. The result showed that decomposition rate of the rice straw in the field with short bund distance (4 meters) is higher than in the field with long bund distance (8 meters). Decomposition rate based on the difference of litterbag showed that in field with short bund distance, coarse mesh litterbag have the higher rate with 93.91%, meanwhile medium mesh size about 89.07% and fine mesh about 81.58%. In long bund distance field, percentage of coarse -, medium - and fine mesh sizes are 88.98%; 85.87% and 78.53%, respectively. This result showed that the field with short bund distance have the higher decomposition rate, indicated that field with short bund distance has more soil fauna population that involved in decomposition process, compared to field with long bund distance.