TURKISH JOURNAL OF AGRICULTURE AND FORESTRY, vol.40, no.3, pp.319-327, 2016 (SCI-Expanded)
Phosphorus use efficiency (PUE) is very low in alkaline calcareous soils; however, it can be improved by using suitable application methods along with farm manure (FM). The present field study was conducted to optimize phosphorus (P) levels and application methods in order to maximize wheat yield, PUE, and net returns on calcareous soils with and without FM application. Five P soil solution levels, i.e. 0.00, 0.05, 0.10, 0.20, and 0.30 mg P L-1, were maintained according to the Freundlich model through the application of 0, 36, 61, 104, and 142 kg P2O5 ha(-1), respectively. The calculated P (0, 36, 61, 104, and 142 kg P2O5 ha(-1)) was applied by broadcasting, band-placement, and top-dressing, with or without 300 kg ha(-1) well-rotted FM. The results revealed that the band-placement technique at 104 kg P2O5 ha(-1) improved PUE and wheat output with and without FM application. Furthermore, wheat grain and straw P uptake was high at 142 kg P2O5 ha(-1). In addition, protein content and Olsen P were high at 142 kg P2O5 ha(-1). The band-placement technique at 104 kg P2O5 ha(-1) increased net returns and the cost/benefit ratio. FM application further augmented the productivity, PUE, and net returns under various P levels and application techniques. In conclusion, band-placement of P at 104 kg P2O5 ha(-1) with FM improved yield, PUE, and net returns of wheat sown on sandy clay loam calcareous soils.