Pengaruh Penambahan Biomassa di Lahan Kering terhadap Diversitas Arthropoda Tanah dan Produktivitas Tebu - Sujak Sujak; Dwi Adi Sunarto; Subiyakto Subiyakto (Buletin Tanaman Tembakau, Serat & Minyak Industri, 2018)
Program pengembangan tebu saat ini diarahkan ke lahan kering yang memiliki ketersediaan air dan kesuburan tanah terbatas.  Kondisi lahan kering dapa menjadi pembatas produktvitas tebu.  Penambahan biomassa ke lahan dapat meningkatkan kesuburan dan populasi arthropoda tanah/detrivora.  Penelitian penambahan biomassa Crotalaria juncea  pada lahan kering  dilaksanakan di Kebun Percobaan Asembagus, Situbondo mulai bulan Januari–Juli 2015. Tujuan penelitian adalah untuk menganalisa pengaruh penambahan biomassa pada lahan kering terhadap diversitas arthropoda tanah dan pengaruhnya terhadap produksi tebu. Perlakuan terdiri atas lahan dengan penambahan biomassa (serasah tebu dan pupuk hijau C. juncea) dan lahan yang tanpa penambahan biomassa.  Pengamatan kelimpahan arthropoda tanah dan tingkat diversitas dilakukan dengan pemasangan pitfall traps dan yellow pan traps. Hasil penelitian menunjukkan bahwa Collembola dan Hymenoptera merupakan arthropoda tanah yang dominan. Indeks diversitas arhropoda tanah pada lahan dengan penambahan biomassa lebih tinggi (0,82–0,84) dibandingkan pada lahan tanpa penambahan biomassa (0,75–0,79). Penambahan biomassa pada tahun pertama dapat meningkatkan kandungan C Organik tanah dari 0,76 menjadi 1,06, dan meningkatkan kandungan N dari 0,03 menjadi 0,11, serta meningkatkan produksi tebu dari 70,4 ton/ha menjadi 101,4 ton/ha. Untuk memperbaiki kondisi ekosistem lahan kering diperlukan penambahan biomassa secara terus menerus.Effect of Biomass Addition in Dry Land to Diversity of Soil Arthropods and Productivity of SugarcaneThe current sugarcane development program is directed to dry lands that have limited water availability and soil fertility, thereby limiting the productivity of sugarcane.  In order to restore soil fertility and reduce the evaporation of groundwater, addition of biomass in the form of trash (dried leaves) of sugarcane as well as the addition of green manure (Clotalaria juncea) is needed.  Biomass addition to the land could increase soil fertility and the population of soil arthropods/detrivores.  The experiment was conducted on dry land at Asembagus Experimental Station, Situbondo from January 2015–July 2015.  The purpose of this research was to analyze the effect of biomass addition to the diversity of soil arthropods and sugarcane productivity.  Treatments consisted of land with the addition of biomass (sugarcane/sugarcane and green manure C. juncea) and control.  Observation of the abundance of soil arthropods and diversity level was done by setting pitfall traps and yellow pan traps, observation was done monthly.  The results showed that the order of Collembola and Hymenoptera were dominant arthropods. The diversity index of ground arhropods on the land with biomass increments was higher (0.82–0.84) than that in the land without biomass addition (0.75–0.79).  The addition of biomass in the first year succeeded in increasing the organic C content of soil from 0.62 to 1.06 and increasing the production of sugar cane from 70.4 tons/ha to 101.4 tons/ha.  In order to improve the ecosystems condition, it is required the addition of biomass continuously.