不同盐渍化土壤N2O排放对生物炭添加和土壤水分的响应

为探讨不同盐渍化程度土壤N₂O排放对生物炭添加和土壤水分的响应，开展为期30 d的室内培养试验，设置5个土壤盐渍化水平(S0、S1、S2、S3、S4:盐分添加量分别为土壤质量的0%、0.25%、0.5%、0.75%、1%)、2个生物炭添加方式(B0:不添加；B1:添加量为土壤质量的5%)和2个水分条件(W0:60%田间持水量；W1:100%田间持水量)。结果表明：土壤盐分对N₂O累积排放量具有显著影响，盐分含量越高则降幅越大，与S0处理相比，S1、S2、S3、S4处理N₂O累积排放量分别降低43.9%、66.5%、91.9%、93.2%。土壤水分对N₂O累积排放量具有极显著影响，水分含量越高则累积排放量越大，与W0处理相比，W1条件下各盐分处理N₂O累积排放量分别增加3.0%、84.8%、187.4%、729.4%、306.7%。生物炭添加对N₂O累积排放量存在一定影响，与B0处理相比，低水含量下，B1处理累积排放量增幅为3.4%～20.6%,高水含量增幅...

Response of soil N2O emission to biochar addition and water content under different salinization conditions

To investigate the response of soil N₂O emission to biochar addition and soil water with different salinization levels, an indoor culture experiment was conducted for 30 days and five soil salinization levels (S0, S1, S2, S3 and S4) were set up. The salt content was 0%, 0.25%, 0.5%, 0.75% and 1% of soil mass, respectively. Two biochar addition modes of B0: no addition and B1: 5% of soil mass and 2 moisture conditions of W0: 60% field capacity and W1:100% field capacity were used. The results showed that soil salt had a significant effect on the cumulative emission of N₂O, and the higher the salt content was, the greater the decrease was. Compared with S0 treatment, the cumulative emission of N₂O in S1, S2, S3 and S4 treatments decreased by 43.9%, 66.5%, 91.9% and 93.2%, respectively. Soil moisture had a significant impact on the cumulative emission of N₂O. The higher the moisture content was, the greater the cumulative emission was. Compared with W0 treatment, the cumulative emission of N₂O in each salt treatment under W1 condition increased by 3.0%, 84.8%, 187.4%, 729.4% and 306.7%, respectively. The addition of biochar had an impact on the cumulative emission of N₂O. Compared with B0 treatment, the increase of B1 in low water content was 3.4% to 20.6%, and that in high water content was 46.5% to 535.6%. The results showed that the higher the degree of salinization was, the lower the cumulative emissions of soil N₂O became. Water had the dominant role in the emission of N₂O as water had a very significant impact on the cumulative emissions of N₂O. The higher the water content was, the higher the increase of cumulative emissions of N₂O became. Biochar alone had no significant impact on the cumulative emissions of N₂O. However, the interaction with salt had a significant effect on the cumulative emission of N₂O, reducing the emission to a certain extent.