还原剂对森林暗棕壤碱解氮测定的影响

Effect of Reductants on the Determination of Base Hydrolyzable N in Dark-Brown Forest Soil

在扩散法测定森林暗棕壤碱解氮中,为明确FeSO_4-Zn还原剂添加的必要性,在添加还原剂的情况下对土壤碱解氮含量进行了测定,并与对照(不添加还原剂)进行比较。回归分析结果表明：两处理测定值间相关极显著。当扩散时间在8、12、18、24、30、48 h时,土壤碱解氮扩散量与扩散时间呈直线相关,在24 h内,对照所测得的碱解氮结果快速、准确、稳定。测定森林暗棕壤碱解氮时不添加还原剂较为合适。

Content of base hydrolysable N in dark-brown forest soil was determined under the presence of reductant FeSO4-Zn by diffusion method in order to approach the necessity of adding reductant, and the determination result was compared with the control with the absence of reductants. Regression analysis result showed that significant difference in content of base hydrolysable N was found between the two treatments. The diffused content of base hydrolysable N was linear with diffusion time within 8, 12, 18, 24, 30 and 48 h. Within 24 h, the determination result of the control with absence of reductants was fast, exact and steady. It is suggested that adding no reductant is appropriate in the determination of base hydrolysable N in dark-brown forest soil.