Greenhouse evaluation of wheat yield and phosphorus uptake in relation to labile-P, olsen-p and their ratio under different calcareous soil conditions
2000
Rashid, A. (Ayub Agricultural Research Inst., Faisalabad (Pakistan). Soil Bacteriology Section) | Hussain, T. | Razzaq, A.
Due to complex soil phosphate (P) chemistry, further improvement in the assessment of available soil P in crop production is needed. This study was conducted to determine whether the Olsen-P (NaHCO3, extractant) or labile-P (HCO3-resin) test methods in combination with labile-P/Olsen- P ratio, working roughly as soil P buffering capacity, could improve the assessment of soil available P. Regression relationship of Olsen-P, labile-P and labile-P/Olsen-P ratio with wheat (Triticum aestivum L.) relative yield and P uptake were investigated using 19 alkaline calcareous soils collected from upper 30 cm layer with initial P treatment at the rates of 0, 30, 60 and 90 mg P kg-1 soil before cropping in a greenhouse experiment. For relative yield, Olsen-P alone was observed the best test to use (R square = 0.932) and it was not affected by including labile- P/Olsen-P ratio (Rsquare = 0.935). The critical levels of 13 and 23 mg P kg-1 soil for the Olsen-P and labile-P respectively resulted in relative yield of about 75 percent. For P- uptake, both Olsen-P (R square = 0.729) and labile-P (R square = 0.751) methods showed almost similar relationships and inclusion of labile- P/Olsen-P ratio did not improve the R square values (with Olsen-P, R square = 0.771; with labile-P, R square = 0.785) for P uptake significantly for practical purposes. However, further work in this direction including soil characteristics (and P buffering capacity) is needed.
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Эту запись предоставил National Agricultural Research Centre