外源生物质炭对土壤中铵态氮素滞留效应的影响

以生物质炭和黄棕壤为研究材料,通过阳离子交换量测定、铵态氮等温吸附实验以及模拟土柱淋溶,研究生物质炭对土壤铵态氮素滞留效应的影响。发现生物质炭以1%、3%和5%添加后,土壤CEC值分别增加9.4%、14.7%和19.7%,铵态氮素淋失量分别减少22%、39%和47%,氮素滞留量分别增加15%、5%和14%;同时影响氮素在土层中的分布,其中加生物质炭土壤的氮素集中在土柱上部5～7cm处,而不加生物质炭土壤集中在中部偏下9～11cm处。结果表明,生物质炭能够提高土壤对铵态氮素的吸附能力,显著降低土壤铵态氮素养分的淋失。

Effects of Biomass Charcoals on Retention of Ammonium Nitrogen in Soils

Application of biomass charcoals(BCs) to soils may affect physicochemical properties and composition structure of soils,and further change environmental behavior of nutrition in soils.The influence of BCs on the adsorption and leaching of ammonium nitrogen in soils was investigated with BCs through CEC determination,isothermal ammonium adsorption and the soils column leaching in yellow-brown soils.The results showed that for the addition of 1%,3% and 5% BCs,the cation exchange capacity of soils increased by 9.4%,14.7% and 19.7%;the ammonium nitrogen loss decreased by 22%,39% and 47%,and the nitrogen retention increased by 15%,5% and 14%,respectively.For the distribution of N in soils layers influenced by the addition of BCs,the nitrogen concentrated at top 5～7 cm in BC-added soils,whereas the nitrogen of the control concentrated at lower 9～11 cm.Therefore,it is indicated that the addition of BCs can enhance the adsorption of ammonium nitrogen onto soils,and reduce the loss of soils ammonium nitrogen by leaching.