Utilization of phosphorus by onion and chilli as influenced by depth of placement

摘要

Effect of depths of placement and levels of applied P fertilizer was studied in chilli and onion using ~(32)P labelled superphosphate. In both the crops, placement at 5 cm showed greater uptake and utilization of fertilizer P. A saving of 20 per centin fertilizer P input was possible in onion as application of 80 per cent recommended P at 5 cm depth showed greater fertilizer P uptake (4.79 kg/ha) and bulb yield (63.43 t/ha) although the highest fertilizer P utilization (27.3 per cent) was obtained by placement of 60 per cent recommended P at 5 cm depth. No saving in fertilizer P input was possible in chilli due to better placement as any reduction of applied P either adversely reduced fertilizer uptake or fruit yield.