FERTILIZER MANAGEMENT OF N-P-K WITH BIOFERTILIZER FOR RETAINING SOIL NITROGEN AND PHOSFOR CONTENT AND CROPS OF SOYBEAN

Abstract

<p>Salah satu upaya untuk meningkatkan produktivitas kedelai pada Inceptisols Jatinangor ialah dengan memanfaatkan inokulan mikroorganisme tanah seperti bakteri pemfiksasi nitrogen dan pelarut fosfat dalam bentuk pupuk hayati khusus kedelai tanpa meninggalkan pupuk anorganik sebagai sumber hara tersedia untuk tanaman. Penelitian ini bertujuan mengetahui pengaruh manajemen pemupukan N-P-K dengan pupuk hayati dalam mempertahankan kandungan hara N dan P serta hasil kedelai. Penelitian dilaksanakan pada bulan April hingga Juli 2016, disusun dengan Rancangan Acak Kelompok (RAK) sederhana yang terdiri dari 10 perlakuan. Kombinasi perlakuan N-P-K dengan pupuk hayati sebagai berikut A = Kontrol (tanpa pupuk), B = N-P-K Standar, C = 1 PHKK + 0 N-P-K, D = 1/4 N-P-K + 1 PHKK, E = 1/2 N-P-K + 1 PHKK, F = 3/4 N-P-K + 1 PHKK, G = 1 N-P-K + 1 PHKK, H = 3/4 + 1/4 PHKK, I = 3/4 N-P-K + 1/2 PHKK dan J = 3/4 N-P-K + 3/4 PHKK. Hasil penelitian menunjukkan dosis pupuk hayati dengan N-P-K yang dianjurkan ialah perlakuan E yaitu 1 PPHK (250 kg ha<sup>-1</sup>) bersama 1/2 N-P-K (37,5-50-50 kg ha<sup>-1</sup>). Dosis tersebut mampu meningkatkan kandungn nitrogen dan fosfor tanah, tanaman, serta hasil kedelai dengan peningkatan hasil sebesar 0,4 t ha<sup>-1</sup> atau 32% dari N-P-K standar.</p><p> </p><p>One effort to increase the productivity of soybeans in Inceptisols Jatinangor is through utilize inoculant of soil microorganisms such as nitrogen-fixing bacteria and phosphate-solubilizing bacteria in the form of specific biofertilizer (SB) for soybean plant without leaving inorganic fertilizer as a source of available nutrients to plants. This research aimed to determine fertilization management of N-P-K and specific biofertilizer in retaining N and P availability and yield of soybean. The Research was conducted from April to July 2016, arranged in Simple Randomized Block Design (RBD) and consisted of 10 treatments. The combination of biofertilizer and N-P-K were as follows; A = control (without fertilizer), B = Standard N-P-K, C = 0 N-P-K + 1 SB , D = 1/4 N-P-K + 1 SB, E = 1/2 N-P-K + 1 SB, F = 3/4 N-P-K + 1 SB, G = 1 N-P-K + 1 SB, H = 3/4 + 1/4 SB, I = 3/4 N-P-K + 1/2 SB dan J = 3/4 N-P-K + 3/4 SB. The results showed a dose of N-P-K and biofertilizer was recommended in the treatment E (250 kg ha<sup>-1</sup> SB) and 1/2 N-P-K (37.5-50-50 kg ha<sup>-1</sup>). The dose was able to increase nitrogen and phosphor content in soil and plant, also on yield of soybean up to 0.4 t ha<sup>-1</sup> or 32% of a standard N-P-K.</p>