Effects of Silicon and Phosphatic Fertilization on Rice Yield and Soil Fertility

A pot experiment was conducted to investigate the effects of silicon and phosphatic fertilization on rice yield and soil fertility. Three levels of silicon (Si) fertilization i.e., SiO2: 45, 135, and 225 kg hm(-2) and the two phosphatic fertilizer i.e., P2O5: 15 and 45 kg hm(-2) for each of calcium superphosphate (CS) and combined calcium-magnesium phosphate (FCMP) (used as phosphatic fertilizer source) were applied to a rice cultivar II you 128. The treatment applied with P2O5 45 kg hm(-2) CS and without Si fertilization was taken as control (CK). The grain yield was improved with increasing Si fertilizer application, whereas phosphatic fertilization also affected the grain yield significantly. The FCMP showed better grain yield than CS whereas the interactive effect of Si and CS fertilizer showed higher Si contents in stem sheath, available Si in soil, water-soluble Si contents in soil and soil active Si contents but lower available phosphorus in soil and soil phosphatase activity than the Si and FCMP fertilizer interaction. Moreover, the grain yield showed significant positive correlation with aboveground dry weight (r = 0.9951) and harvest index (r = 0.8364). Overall, Si fertilization improved rice yield, whereas FCMP was found better than CS regarding grain yield improvement. The grain yield increased with increasing Si fertilizer application whereas the FCMP was found better than CS regarding grain yield improvement of rice. The supplementation of Si and phosphatic fertilizers substantially improved available Si and P contents of soil.