牛粪生物炭对土壤氮肥淋失的抑制作用

Inhibitory Effects of Dairy Manure Biochar on Soil Nitrogen Leaching

为了探讨以牛粪为原材料制备的生物炭对土壤氮肥淋失的抑制作用,对牛粪生物炭的结构和元素组成进行了表征和分析,并通过人工模拟土柱氮肥淋失实验,研究了生物炭对淋滤液p H值、铵态氮、硝态氮和总氮累积淋失总量及浓度影响。结果显示:该生物炭具有发达的管状孔洞结构,K,Ca含量比牛粪增加200%和10%;淋滤液p H值随着生物炭比例增加而提高,生物炭5%与对照0%相比,淋滤10天,p H值增幅最大,为12.5%;淋滤30天内,按生物炭0%、2%、3%、4%和5%,铵态氮和硝态氮浓度逐渐降低。淋滤大于40天,生物炭的添加延缓了土壤中硝态氮的淋失时间。生物炭4%~5%,对土壤氮肥淋失的抑制效果最佳,与对照0%相比,铵态氮、硝态氮和总氮累积淋失总量分别减少了16%、32%和32%左右。

To explore the inhibitory effects of the biochar made by dairy manure as raw material against soil nitrogen fertilizer leaching, this paper characterizes and analyzes the structure and elements of dairy manure biochar, and carries out manual simulations of soil column experiments on soil leaching, based on which we study the impacts of dairy manure biochar on 1) the p H value of soil leachate, and 2) overall cumulative loss amount and concentration of ammonium nitrogen, nitrate nitrogen, and total nitrogen. The results show that compared to dairy manure, dairy manure biochar possesses more developed tubular hole structures, and has 200% and 10% more K and Ca substances,respectively. The p H value of soil leachate tends to increase with increasing addition of dairy manure biochar.Compared to 0%, with 5% addition of dairy manure biochar, leachate p H values exhibit the greatest increasing amount of 12.5% on the 10 th day of the leaching experiment. In the 30 day experimental period, concentration of ammonium nitrogen and nitrate nitrogen concentrations are gradually reduced with the addition of dairy manure biochar at 0%,2%, 3%, 4% and 5%, respectively. Beyond the 40 day experiment, the leaching time of nitrate nitrogen on soil is delayed with the addition of biochar. When the addition of dairy manure biochar is 4% ~ 5%, the inhibitory effects of dairy manure biochar on soil nitrogen fertilizer leaching are most effective. Compared to the addition 0% of dairy manure biochar, overall cumulative loss amount of ammonium nitrogen, nitrate nitrogen, and total nitrogen are reduced by about 16%, 32% and 32%, respectively.