Performance of fertigation technique for phosphorus application in cotton

Low native soil phosphorus availability coupled with poor utilization of added phosphorus is one of the major constraints limiting the productivity of the crops. With a view of addressing this issue, field studies were conducted to compare the relative efficacy of broadcast and fertigation techniques for phosphorus application during 2005-2006 using cotton as a test crop. Two methods of phosphorus application i.e. broadcast and fertigation were evaluated using five levels of P2O5 (0, 30, 45, 60 and 75 kg P2O5 ha(-1)). Fertigation showed an edge over broadcast method at all levels of phosphorus application. The highest seed cotton yield was recorded with 75 kg P2O5 ha(-1). Fertilizer phosphorus applied at the rate of 60 kg ha(-1) through fertigation produced 3.4 tons ha(-1) of seed cotton yield, which was statistically identical to 3.3 tons recorded with 75 kg ha(-1) of broadcast phosphorus. Agronomic performance of phosphorus was influenced considerably by either method of fertilizer application. The seed cotton yield per kg of fertigation phosphorus was 48% higher than the corresponding broadcast application. The results of these studies showed that fertigation was the most efficient method of phosphorus application compared with the conventional broadcast application of fertilizers.