Sulphur-P~osphorus Interaction on the Synthesis of Nitrogenous Fractions and Oil in Soybean
Abstract
A greenhouse study was conducted to evaluate the influence of fertilizer phosphorus and sulphur application (@ 0, 25, 50 and 75 kg ha−1 individually as well as in combination) on protein and oil synthesis in soybean grown on sulphur and phosphorus deficient Vertisol. The protein synthesis in soybean grain was suppressed at low levels of S and P with a concomitant increase in the deposition of undesirable non-protein nitrogenous (NPN) compounds, viz. nitrate, ammoniacal, amide and amino acid-No Amongst NPN, the amino acid-N declined significantly from control to 50 kg dose of Sand P. In contrast, the seed yield, protein and oil content significantly increased with successive application up to 50 kg dose in comparison to control. Relative contribution of P to the yield, protein and oil synthesis was found to be similar in trend. However, effect of P in reducing the NPN content was less spectacular as compared to that of sulphur.
Keywords
Vertisol, P and S nutrition, soybean, protein, non-protein, oil content
