生物质炭及硝化/脲酶抑制剂对滨海盐渍土土壤盐分及作物氮素吸收利用的影响

为研究生物质炭及硝化/脲酶抑制剂对滨海盐渍土土壤盐碱、氮素有效性、作物氮素吸收利用以及土壤氮平衡的影响,通过盆栽试验,共设9个处理:不施氮肥、常规化肥、生物质炭+常规化肥、常规化肥+硝化抑制剂DCD、常规化肥+脲酶抑制剂NBPT、常规化肥+DCD+NBPT、生物质炭+常规化肥+DCD、生物质炭+常规化肥+NBPT、生物质炭+常规化肥+DCD+NBPT,以典型耐盐作物大麦为研究对象开展研究。结果表明:(1)各施氮肥处理均增加了盐分的淋洗,各生物质炭处理显著增加了10～20 cm土层的土壤电导率。土壤电导率高的土壤p H较低,生物质炭处理对土壤p H略有降低的作用。(2)NBPT和DCD添加增加了大麦籽粒产量,配合生物质炭的施用增产更多,但是却降低了秸秆的产量。NBPT和DCD添加均增加了大麦植株的吸氮量,其中NBPT添加增加了大麦秸秆和籽粒的全氮含量,但是配合生物质炭施用又有降低作用,其余抑制剂处理均降低了大麦籽粒和秸秆的全氮含量。(3)DCD和NBPT添加均提高了氮肥利用效率,配合生物质炭施用对各指标的增加更明显。(4)对作物收获后土壤残留无机氮含量,添加DCD处理相比常规化肥处理有所降低,添加NBPT处理相比常规化肥处理有所增加。添加DCD和NBPT处理均降低了氮的表观损失。因此,在滨海盐渍土中,通过在尿素中添加DCD和NBPT,可以提高作物产量和氮肥利用率,其中同时添加生物质炭、DCD和NBPT处理在产量提升、氮素高效利用及减少氮损失等方面表现更好。

Effects of Biochar and Nitrification / Urease Inhibitors on Soil Salinity and Crop Nitrogen Absorption and Utilization in Coastal Saline Soil

Coastal saline soil has higher salinity and pH, thus it accelerates the loss of soil nitrogen and reduces the absorption and utilization of nitrogen by crops.In order to study the effects of biochar and nitrification / urease inhibitors on soil salinity and alkalinity, nitrogen availability, crop nitrogen absorption and utilization and soil nitrogen balance in coastal saline soil, a pot experiment was carried out with barley, a typical salt tolerant crop, as the research object,a total of 9 treatments were set up in the experiment: only applying phosphate fertilizer (NOP), conventional fertilizer (F), biochar + conventional fertilizer (BF), F + nitrification inhibitor DCD (FD), F + urease inhibitor NBPT (FN), F + nitrification Inhibitor DCD + urease inhibitor NBPT(FDN), BF + nitrification inhibitor (BFD), BF + urease inhibitor (BFN), BF + nitrification inhibitor + urease inhibitor (BFDN). The results showed that: (1) All nitrogen fertilizer treatments increased salt leaching, and all biochar treatments significantly increased soil electrical conductivity in 10-20cm soil layer. The soil with high soil electrical conductivity had lower pH, Biochar treatment slightly reduced soil pH. (2) NBPT and DCD increased the grain yield of barley, and the application of biochar increased the yield of barley more, but decreased the yield of straw. NBPT and DCD increased the nitrogen uptake of barley plants, and NBPT increased the total nitrogen content of barley straw and grain, but decreased with biochar application, and other inhibitor treatments decreased the total nitrogen content of barley grain and straw. (3) Both DCD and NBPT improved the nitrogen use efficiency, and the increase of each index was more obvious with the application of biochar. (4) compared with F treatment, the content of soil residual inorganic nitrogen in DCD treatment was lower while that in NBPT treatment was higher.DCD and NBPT treatments reduced the apparent loss of nitrogen. Therefore, by adding DCD and NBPT to urea, the yield of crops and nitrogen use efficiency can be increased in coastal saline soil and BFDN treatment performed better in increasing yield, efficient use of nitrogen and reducing nitrogen loss.