Effect of method and time of application on P use efficiency by mustard (Brassica juncea L.)

Radiophosphorus(32p) employed in a two years field study to evaluate some techniques of phosphate application in relation to P utilization by mustard as a test crop on I.A.R.I. Farm alluvial soil revealed that split application of phosphate proved superior to other methods of P fertilization as judged by significantly higher values for per cent Pdff and per cent P utilization. Band placement of plain single suprphosphate(SSP) as well as slurry blended SSP 3 to 4 cm below the seed were at par but both were superior to broadcast application of slurry blended SSP in terms of different P uptake parmeters. Fertilizer applied as a traditional practice, i.e, to broadcast it at seeding was least efficiently utilized. Moreover, alternate tagging technique conclusively indicated that mustard crop derived relatively more P from the basal dose than that of side dressed 25 days after seeding. The grain yield response per unit quantity of added P was much higher in favour of split application followed by comparable response of band placement of blended SSP and unblended fertilizer. (author). 12 refs., 2 tabs