Influence of different techniques of P application on yield and fertilizer P absorption by safflower (Carthamus tinctorius L.)

Different techniques of P fertilization viz., application of ³²P labelled single superphosphate (SSP) in plain form and after blending with biogas slury through broadcast, band placement and split application were evaluated in a field study, in relation to P utilization in safflower, Split application proved superior to other methods of P fertilization as noted by significantly higher values for P derived from fertilizer (%Pdff) and P utilization. The performance of ordinary SSP as well as blended SSP both applied through band placement 3-4 cm. below the seed was comparable but both were significantly better over the same applied through broadcast in terms of different P uptake parameters as well as grain yield response per unit quantity of added P. Phosphorus broadcast at seeding was least efficiently used. The alternate tagging technique conclusively indicated that safflower crop absorbed relatively more P from the basal dose than sidedressed (15 kg P₂O₅ each) 25 days after sowing.