Abstract
Phosphorus use efficiency of urea phosphate (17% N and 44% P2O5 ) and di-ammonium phosphate (18% N and 46% P) were evaluated in saline soil (ECe10.05 dS/m & pH 7.64) on wheat, grown in pots containing 10 kg soil. Phosphorus application rates from either source were (0, 20, 40, 60 and 80 mg P2O5 kg-1 soil) at the sowing time whereas urea was applied @ 150 kg N ha-1 in two splits (at sowing and anthesis). The agronomic data revealed that plant height and spike length increased with increase in phosphorus fertilizer rate (irrespective of source). Urea phosphate showed its superiority over DAP for grain yield as well as P-fertilizer efficiency (PFE). Urea phosphate at 60ppm P2O5 produced higher grain yield (9.24g pot-1 ) as compared to DAP (80ppm P2O5, 8.98g pot-1 ). The straw weights obtained with UP and DAP ranged between 11.93-16 g pot-1 and 9.2-13.3 g pot-1 , respectively. Phosphorus uptake in grain was also higher with urea phosphate (9.45-13 mg pot-1 ) as compared to DAP (7.93-11.23 mg pot-1 ).Phosphorus use efficiency of both fertilizers was significantly effected at all levels of phosphorus, however it decreased with increasing level of phosphorus. Highest phosphorus use efficiency (18.95%) was recorded at lowest level of phosphorus by urea phosphate.
