Influence of two phosphate-potassium solubilizing bacterial species on biomass and nitrate concentration on mustard greens (Brassica juncea (L.) Czernjaew) cultivated on acid sulfate soils

Two field trials were conducted to determine the effect of P-K solubilizing bacteria and nitrogen chemical fertilizer on growth, yield and nitrate in leaf of mustard greens Brassica juncea L.) cultivated on acid sulfate soils. Eight P-K solubilizing bacterial strains composed of 3 strains of Acinetobacter calcoaceticus and 5 strains of Rhizobium sp., bacterial liquid were directly watered into plant at 3 stages [6, 12 and 21 days after planting] during vegetable cultivation, chemical fertilizer (60N – 40 P2O5 – 20 K2O) and control (no-inoculation). The study revealed that eight P-K solubilizing bacterial strains have good characteristics as nitrogen fixation, phosphate and potassium solubilisation. Application of nitrogen chemical concentration, increasing nitrate concentration of leaf of mustard greens. Application of bacterial liquid with Acinetobacter calcoaceticus strain NT4 and Acinetobacter calcoaceticus strain NT30 strain, Rhizobium tropici strain N18 and Rhizobium leguminosarum strain K35 on mustard greens cultivated on acid sulfate soils (basal fertilizer: 40 P2O5 – 20 K2O) was the best cultural practice because the this model not only supported the highest biomass, but also decreased nitrate concentration in leaf of mustard greens