... period of plant-grow npk fertilizer : N+P2O5+K2O 15-15-1520-20-20, 19-19-19+TE, 16-16-16, 17-17-17 ... 18-18-18, 12-12-17+MgO, 20-10-12 ... -5-40, 15-10-30, 16-8-3213-13-21+2MgO, 15-5-20+2Mg+6S13-15-15, 18-9 ... -18, 15-5-5, 12-5-14+TE18-4-9+2Mg0, 16-16-8+2MgO Soluble npk ... fertilizer(20-20-20)