土壤中有效钾的快速提取研究

比较了Mehlich3法、1mol/L NH4Ac法、2mol/L冷HNO3法、0.05mol/L HCl 0.0125mol/L H2SO4法等四种土壤有效钾的快速提取方法。对土壤中有效钾的提取率而言,1mol/L NH4Ac法与Mehlich3法基本一致,0.05mol/L HCl 0.0125mol/L H2SO4法则偏低,而2mol/L冷HNO3法则偏高。综合分析认为1mol/LNH4Ac法是比较方便可行。进一步优化了1mol/L NH4Ac法的实验条件。在最佳实验条件下,测定了五个实际土样,所得结果满意;标准加入法回收试验表明,加入回收率为93.8%~96.9%,相对标准偏差为2.6%.

Study on the method of rapid extraction of available potassium in soils

The applicability of four methods on 1mol/L NH4Ac method,2mol/L cold HNO3 method,0.05mol/L HCl and 0.0125mol/L H2SO4 method,Mehlich3 method for extraction of available potassium in soil were have compared.The extraction rates of potassium are the same basically for 1 mol/L NH4Ac and Mehlich 3.While the rate extracted by 0.05 mol/L HCl and 0.0125 mol/L H2SO4 is a little low and the rate by 2 mol/L cold HNO3 is high slightly.Taking it all round 1mol/L NH4Ac method is more convenient and feasible.Thus,1 mol/L NH4Ac was selected as the extraction reagent and the experimental conditions was optimized in detail.Under optimal condition potassium content in five soil samples were determined with satisfaction.And test of standard addition show the recovery of potassium is 93.8~96.9% with 2.6 % of relative standard deviation.