Formulasi Pupuk Hayati dan Pupuk NPK untuk Mendapatkan Viabilitas Mikroba yang Stabil

Abstract

Salinitas yang tinggi pada pupuk NPK dapat mengganggu viabilitas bakteri di dalam pupuk hayati . Penelitian ini bertujuan untuk memformulasikan pupuk hayati berbasis Bacillus spp. dan pupuk NPK guna menjaga stabilitas viabilitas bakteri. Lima formula diuji berdasarkan mutu pupuk, viabilitas bakteri, serta aktivitas bakteri sebagai penambat nitrogen dan bakteri pelarut fosfat. Hasil menunjukkan bahwa semua formulasi memenuhi standar mutu pupuk sesuai SNI 2803:2012. Spektrum FTIR menunjukkan minyak nabati dalam pupuk NPK mengandung gugus alkana (2914 cm-1) dan karbonil (1681–1671 cm-1). Uji viabilitas didapatkan kurva yang ideal untuk pertumbuhan bakteri pada kondisi suhu ruang maupun saat suhu tinggi. Formula A (pupuk NPK dengan biofertilizer dan minyak nabati) menunjukkan aktivitas tertinggi dalam menambat nitrogen (163,31 ppm/koloni di suhu ruang; 115,56 ppm/koloni di suhu tinggi) dan melarutkan fosfat (752,22 ppm/koloni di suhu ruang; 550 ppm/koloni di suhu tinggi). Formula A merupakan variasi terbaik untuk penambahan minyak nabati dan biofertilizer.

High salinity in NPK fertilizers could interfered with the viability of bacteria in biofertilizers. This study aimed to formulate a biofertilizer based on Bacillus spp. and NPK fertilizer to maintain bacterial viability stability. Five formulations were tested based on fertilizer quality, bacterial viability, and bacterial activity as nitrogenfixing and phosphate-solubilizing agents. The results showed that all formulations met the fertilizer quality standards according to SNI 2803:2012. The FTIR spectrum showed that the vegetable oil in the NPK fertilizer contained alkane (2914 cm-1) and carbonyl (1681–1671 cm-1) functional groups. Viability tests produced an ideal bacterial growth curve at room temperature and under high-temperature conditions. Formula A (NPK fertilizer with biofertilizer and vegetable oil) showed the highest activity in nitrogen fixation (163.31 ppm/colony at room temperature; 115.56 ppm/colony at high temperature) and phosphate solubilization (752.22 ppm/colony at room temperature; 550 ppm/colony at high temperature). Formula A was the best variation for the addition of vegetable oil and biofertilizer.