生物炭对砂壤土氮素淋失的影响试验研究

通过室内土柱模拟试验,研究了生物炭对砂壤土的p H值、电导率及氮素淋失的影响。试验设5个生物炭添加比例,分别为0(CK)、1%(T1)、2%(T2)、4%(T3)、6%(T4)。结果表明,p H值和电导率均随生物炭添加比例的增加呈逐渐升高的趋势,其中,各处理砂壤土的电导率较CK分别提高了2.79%、10.88%、11.30%、12.50%。土壤淋溶液中氮素随生物炭添加比例的增加,呈逐渐减小趋势,氮素累积淋溶量也逐渐减小。各处理淋溶液中氮素的淋失总量较CK分别降低了2.89%、7.41%、9.50%和12.25%。研究表明,生物炭能够有效改变砂壤土的理化性质,降低氮素的淋失量,降低地下水面源污染的风险。

Effect of Biochar on Nitrogen Leaching in a Sandy Loam Soil

Column experiments were conducted in laboratory in attempts to study the effect of biochar on pH, EC and leaching of nitrogenin a sandy-loam soil. Five biochar application rates were examined:0％(CK), 1％(T1), 2％(T2), 4％(T3) and 6％(T4). The results showed that pH and electrical conductivity of the soil increased as the ap-plied biochar increased,with electrical conductivity of soil under T1—T4 treatments increasing by 2.79％, 10.88％, 11.3％and 12.50％respectively, compared with the CK. The concentration of leached nitrogen and the accumulated leached nitrogen decreased as the applied biochar increased, with the mass of the leached nitrogen in the T1—T4 treatments reducing by 1.74％, 13.35％, 14.01％and 17.31％, respectively, compared with the CK. In summary, biochar alerted the physical and chemical properties of soil, thereby reducing nitrogen leachingand hence the risk of groundwater pollution by non-point contaminant sources in agroecosystems.