Extraction of nonexchangeable potassium from soils with boiling one molar nitric acid: evaluation of different modes of boiling the soil-acid suspension
2000
Srinivasa Rao, C. | Subba Rao, A. | Singh, S.P.
The standardization of kind and extent of boiling during the course of extraction of potassium (K) from soil in strong acid medium is crucial for obtaining a reliable and reproducible estimate of the nonexchangeable K concentration in soil. In the present study, relationships among the amounts of K extracted by different modes of boiling soil-acid mixture adopted, i.e., heating mantle, hot plate and burner were established. Irrespective of the dominant mineralogy of soils, boiling on hot plate gave higher estimate of K followed by heating mantle and lower values were observed in case of burner. Among the methods, boiling on heating mantle showed lower mean standard deviation (32.32 mg kg(-1)) and lower coefficient of variation (4.9%) followed by hot plate (SD=52.43 mg kg(-1); CV=7.26%) and burner (SD=56.30 mg kg(-1); CV=9.48%). Based on precision analysis, boiling of soil-acid suspension on heating mantle and hot plate was found to be superior to that on gas burner in extracting nonexchangeable K from soils.
显示更多 [+] 显示较少 [-]