ISSN:
1573-0867
Keywords:
Phosphate adsorption
;
external P requirement
;
wheat
;
fertilizer requirements
;
calcareous soils
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Five field experiments involving P application rates from 0 to 66 kg P ha−1 were conducted on irrigated wheat at Tandojam, Pakistan. The soils belonged to two great soil groups, Torrifluvent and Camborthid. All soils were calcareous. Olsen-P contents ranged from 3.5 to 6.3 mg P kg−1. Phosphate sorption curves were developed for soils from control (no P) plots at each site. Concentrations of P in solution established by fertilization in the field as estimated from the sorption curves ranged from 0.008 to 0.16mg P L−1. Actual grain yields were converted to relative grain yields and plotted against corresponding concentrations of P in solution. Yield response to P application was obtained in each experiment. Control plot yields ranged from 57 to 89% of maximum yield of respective experiments. Phosphorus requirements of wheat were 0.032 mg L−1 for 95% yield as determined from a composite yield response curve. Predicted quantities of P required to attain 0.032 mg P L−1 ranged from 18 to 29 kg P ha−1. The results of the study suggest that the P sorption approach can be used as a rational basis for making P fertilizer recommendations for various soil-crop combinations.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01048857
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