Tomat (lycopersicum esculentum) merupakan sayuran yang banyak diminati masyarakat di indonesia. peningkatan produksi tomat di indonesia didukung oleh berbagai faktor, salah satunya teknik budidaya yang baik dengan menyediakan nutrisi yang cukup untuk tanaman. penambahan bahan organik merupakan salah satu upaya untuk menambah ketersediaan nutrisi di dalam tanah. salah satu produk sampingan yang dapat dijadikan bahan pupuk organik adalah kulit ubi kayu dan umumnya sudah tidak dimanfaatkan. kompos ubi kayu bermanfaat sebagai sumber nutrisi bagi tumbuhan dan berpotensi sebagai insektisida karena mengandung chn yang tinggi. bahan organik tanah berperan penting untuk kesuburan tanah dan dapat meningkatkan pertumbuhan dan aktivitas mikroba. sampai saat ini belum terdapat laporan mengenai perubahan kelimpahan mikroba pada tanah yang diberi pupuk kompos ubi kayu yang mampu mempengaruhi pertumbuhan tanaman tomat. penelitian ini dilaksanakan pada mei-juli 2018 alat yang digunakan adalah laminar air flow (laf), autoclave, plastik tahan panas, cawan petri, microbiology glass bead, alumunium foil, wrapping, lampu bunsen, timbangan analitik, mikro pipet, gelas ukur, erlenmeyer, tabung reaksi, panci, kompor listrik, alat tulis, kertas label, inkubator, dan lemari pendingin. bahan yang digunakan dalam penelitian adalah tanah dari masingmasing perlakuan yang dikompositkan sebanyak 500 gram, media nutrient agar (na) skim milk agar (sma), potatos dextrose agar (pda) dan pikovskaya’s (pvk), spritus, alkohol, akuades. media na, sma, dan pda merk “merck” (jerman), sedangkan pvk merk “himedia” (india). sampel tanah yang diambil berupa tanah yang sebelum ditanami tanaman tomat dan setelah panen sampel diambil dari rhizosfer tanaman tomat, dengan perlakuan p0 = (kontrol), p1 (tanah + kulit ubi kayu 1250 g/polybag) p2 (tanah + kulit ubi kayu 1500 g/polybag), p3 (tanah + kulit ubi kayu 1750 g/polybag). parameter penelitian: jumlah bakteri dan cendawan tanah, bakteri dan cendawan pelarut fosfat, bakteri dan cendawan proteolitik, bakteri dan cendawan kitinolitik, bakteri bacillus sp, nematoda parasit tanaman. hasil penelitian menunjukkan bahwa: 1) aplikasi kompos berbahan kulit ubi kayu pada jumlah bakteri tanah, jumlah bakteri proteolitik, jumlah bakteri pelarut fosfat, jumlah bakteri kitinolitik, bakteri bacillus sp., jumlah cendawan tanah, jumlah cendawan proteolitik, jumlah cendawan kitin, jumlah namatoda parasit tanaman dalam media tanah sebelum dan sesudah tanam berpengaruh tidak nyata, namun berpengaruh nyata untuk jumlah cendawan pelarut fosfat, 2) aplikasi kompos berbahan kulit ubi kayu dalam media tanah sebelum tanah pada perlakuan p2 (tanah + kulit ubi kayu 1500 g/polibag) menghasilkan jumlah bakteri tanah tertinggi (263,33) dan jumlah bakteri proteolitik tertinggi (229,33) dibandingkan dengan perlakuan lainnya. 3)pada hasil penelitian ini ditemukan mikroba yang menguntunkan bagi tanaman adalah bakteri tanah, bakteri proteolitik, bakteri pelarut fosfat, bakteri kitinolitik, bakteri bacillus sp., cendawan tanah, cendawan proteolitik, cendawan pelarut fosfat, cendawan kitinolitik dan mikroba yang merugikan bagi tanaman adalah nematoda parasit tanaman. berdasarkan hasil penelitian ini maka perlu dilakukan penelitian lanjut untuk mengetahui spesies mikroba apa saja yang hidup di rhizosfer tanaman tomat setelah diaplikasikan kompos berbahan kulit ubi kayu.

Tomato (lycopersicum esculentum) are vegetable that are in great demand in indonesia. increased tomato production in indonesia is supported by various factors, one of which is good cultivation techniques by providing sufficient nutrients for plants. addition of organic matter is one of the efforts to increase the availability of nutrients in the soil. one of the byproducts that can be used as organic fertilizer ingredients is cassava skin and is generally not used. cassava compost is useful as a source of nutrition for plants and has the potential as an insecticide because it contains high chn. organic matter plays an important role for soil fertility and can increase microbial growth and activity.until now there have been no reports of changes in microbial abundance in soils which are given cassava compost which is able to affect the growth of tomato plants. the research was conducted from may to july 2018 the tools to be used in the study were laminar air flow (laf), autoclave, heat-resistant plastic, petri dishes, microbiology glass bead, aluminum foil, wrapping, bunsen lamps, analytical scales, micro pipettes , measuring cups, erlenmeyers, test tubes, pans, electric stoves, stationery, label paper, incubators, and refrigerators. the material used in the study was soil from each treatment which was composted as much as 500 grams, nutrient agar (na), skim milk agar (sma), potatos dextrose agar (pda), and pikovskaya's (pvk)), spritus, alcohol, distilled water. na, sma and pda media use the brand "merck" (germany), while pvk uses the brand "himedia" (india). soil samples taken in the form of soil before planting tomatoes and after harvest. samples were taken from rhizosphere of tomato plants, with treatment p0 (control), p1 (soil + cassava peel 1250 g / polybag), p2 (soil + cassava peel 1500 g / polybag), p3 (soil + cassava peel 1750 g / polybag). research parameters: amount of soil bacteria and fungi, phosphate solvent bacteria and fungi, proteolytic bacteria and fungi, chitinolytic bacteria and fungi, bacillus sp. bacteria, and plant parasitic nematodes. the results showed that: 1) application of compost made from cassava skin on the amount of soil bacteria, proteolytic bacteria, phosphate solvent bacteria, chitinolytic bacteria, bacillus sp. bacteria, soil fungi, proteolytic fungi, chitin fungi, plant parasites in the soil media before and after planting have no significant effect, but have a significant effect on the amount of phosphate solvent, 2) application of cassava skin compost in soil media before the soil in p2 treatment (soil + cassava peel 1500 g / polybag) produces the highest number of soil bacteria (263.33) and the highest number of proteolytic bacteria (229.33) compared to other treatments, 3) the results of this study found that microbes that benefit plants are soil bacteria, proteolytic bacteria, phosphate solubilizing bacteria, chitinolytic bacteria, bacillus sp. bacteria, soil fungi, proteolytic fungi, phosphate solvent fungi, kitino fungi lytic and microbial detrimental to plants are plant parasitic nematodes. based on the results of this study, further research is needed to find out what microbial species that live in the rhizosphere of tomato plants after applying compost made from cassava skin.