Peningkatan populasi dan keragaman fauna tanah melalui pengelolaan hayati tanah pada budidaya System of Rice Intensification (S.R.I.) di Kecamatan Cibungbulang, Kabupaten Bogor

Abstract

Soil fauna is important component in the soil ecosystem. They play a very important role in organic matter decomposition, nutrient cycling, nutrient availability and uptake, soil physical properties, prevention of nutrient leaching, and maintain plant health through natural predation and parasitism of plant pathogens and pest. Land management practice can affect soil fauna population and diversity, therefore land management should be environmental frindly, in order to preserve the ecosystem and consequently improve diversity of the soil fauna. In the rice field ecosystem, modification of bund distance is one of managements to improve population and diversity of soil fauna. This research aimed to evaluate the effect of different bund distance (4m and 8m) on soil fauna population and diversity in System of Rice Intensification (S.R.I.). S.R.I. is an innovative cultivation technique to increase yields. The basic principles of S.R.I. method are the use of young seedling of 8-12 days old, wide spacing of 30 cm x 30 cm, maintain unflooded soil condition and planting with a single seed. The research was conducted in Cibungbulang sub district of Bogor regency and Laboratory of Soil Biotechnology of Soil Science and Land Resource Department, Bogor Agricultural University. The research used a treatment of bund distance with two levels (4m and 8m) and four replications. The result showed that the abundance and biomass of soil fauna in plot with 4m bund distance (4m plots) were 26259 individual/m2 and 11.7 g/m2, respectively, and plot with 8m bund distance (8m plots) were 8402 individual/m2 and 2.3 g/m2, respectively. Abundance and biomass of soil fauna in 4m bunds were 25343 individu/m2 dan 10.8 g/m2, respectively, meanwhile in 8m bunds were 19611 individu/m2 and 6.4 g/m2, respectively. The cultivation of soybean in the bund was proven to be able to increase soil fauna population in the bund, that can be seen from 0 day to 90th days. Diversity Index calculated according to Shannon Diversity Index showed the low value (< 1.5) in both 4m plots and 8m plots. The most dominant animals in 4m and 8m plots was Collembola, meanwhile in the bunds was Hymenoptera. The rice productivity determined by the parameters of yield (ton/Ha), filled and empty grain percentage (%), and weight of 1000 grains (g) showed a higher value in 4m plots, as compared to 8m plots. The results in 4m plots based on parameters above were 5.08 ton/ha, 82.64 % 17.36 % and 26.87 g, respectively, meanwhile in 8m plots were 4.96 ton/ha, 76.39 %, 23.61 % and 26.29 g, respectively.