ABSTRAKPenelitian ini dilakukan untuk menguji pengaruh pemberian isolat mikroba endofit yang berasal dari batang padi varietas Mira-1. Teknik 15 N digunakan untuk mengetahui kontribusi masing-masing isolat pada serapan N dalam jerami dan gabah padi. Penelitian dilakukan pada bulan Nopember 2013 hingga Maret 2014 bertempat di Rumah Kaca dan Laboratorium Pemupukan dan Nutrisi Tanaman, PAIR BATAN, Jakarta Selatan. Rancangan acak lengkap dengan 5 kali ulangan digunakan dalam penelitian ini. Perlakuan yang diberikan meliputi pemberian isolat A1, A3, dan A6 sebagai pembanding digunakan kontrol (tanpa perlakuan) dan pemberian urea 100%. Isolat A3 memberikan peningkatan tertinggi terhadap berat kering tanaman padi dan jumlah malai dengan peningkatan berturut-turut sebesar 33.29% dan 37.73% dari kontrol. Teknik 15 N menunjukkan bahwa kontribusi perlakuan A3 dan A6 tidak berbeda nyata dibandingkan dengan kontrol positif (pemberian urea rekomendasi). Perunutan dengan teknik 15 N berhasil menggambarkan bahwa penambatan N 2 paling banyak terjadi di jerami padi.Kata Kunci : Pupuk hayati, Endofit, Nitrogen, Padi, Isotop
ABSTRACTThis study was conducted to examine the effect of endophytic microbes from paddy straw (MIRA-1 variety). The 15 N technique was used to study the contribution of each endophyte microbes on N uptake. This research was conducted from November 2013 to April 2014 at Greenhouse and Laboratory of Fertilization and Plant Nutrition, PAIR BATAN, South Jakarta. This research used completely randomized design with 5 treatments repeated 5 times. The treatments were A1, A3, A6 (as isolates), K-(without treatment), and K+(100% urea). The experimental results showed that the isolates A1, A3, and A6 are bacillus-shape Gram-negative bacteria which have potential applicationas biological fertilizer. Isolate A3 gave the highest result to increase plant dry weight and number of panicles with 33.29% and 37.73% increasement in compare to control, respectively. The 15 N technique showed that the contribution of A3 and A6 treatment gave no significantly effect to positive control (urea recommendation) . The 15 N technique also succeeds to illustrate that N 2 fixation is mostly occurs in rice straw.