Effect of rates and sources of phosphorus on productivity and economics of rice (Oryza sativa) as influenced by crop-residue incorporation Sharma S. N.*, Prasad R., Shivay Y.S., Dwivedi M.K., Kumar Sandeep, Kumar D. Division of Agronomy, Indian Agricultural Research Institute, New Delhi, 110 012. *Corresponding author: (E-mail: snsharma_agro@yahoo.com)
Abstract A field experiment was conducted at New Delhi for 3 years during rainy season (kharif) of 2001 to 2003 to study the effect of crop-residue incorporation on the relative efficiency of di-ammonium phosphate (DAP) and Mussoorie rock phosphate (MRP) in rice (Oryza sativa L.). Phosphorus application generally increased the growth and yield parameters, yields as well as gross and net returns of rice. The increase of these parameters was however significant when the rate of P application was increased from 0 to 35 kg P/ha. At 35 kg P/ha MRP in conjunction with phosphate solubilizing bacteria (PSB) was statistically on a par with DAP, increasing the grain yield by 10–17%, P uptake by 26–54%, available P content in soil by 12–99% and net profit by 15–37% over the control. Agronomic efficiency and apparent recovery of DAP were higher than those of MRP at 17.5 kg P/ha, but on a par with those at 35 kg P/ha. Crop-residue incorporation had no significant effect on grain yield but it significantly increased the apparent recovery of applied P and available P content of soil. Thus, the combined application of MRP, PSB and crop residue proved a good practice that can be used as P fertilizer for rice. Top Key words Agronomic efficiency, Diammonium phosphate, Gross and net returns, Mussoorie rock phosphate, Phosphorus-solubilizing bacteria, Yield. Top |