核桃青皮对土壤中氮转化的影响

发布时间：2018-08-08 16:31

【摘要】：核桃是山西的一种特色农产品,种植面积达40万公顷。核桃青皮是核桃外部一层厚厚的绿色果皮,其主要成分有萘醌及其苷类、黄酮及其苷类、二芳基庚烷类、萜类、有机酸类等一系列化合物。核桃青皮具有化感作用,能够抑制土壤中氮硝化、减少N2O等氮氧化物的排放。此外,核桃青皮作为有机物质施入土壤可以提高土壤有机质含量。本文采用模拟土培试验比较了核桃青皮与双氰胺(DCD)和楝粉对氮的硝化作用的抑制效果,筛选出核桃青皮抑制氮硝化作用较适宜的用量,探讨了核桃青皮在酶学和微生物学上的硝化抑制机理,旨在为核桃青皮作为一种生物硝化抑制剂提供科学依据。试验结果如下:1核桃青皮施入土壤可以显著降低尿素在土壤转化过程中NO3--N的含量而增加NH4+-N含量。土壤中加入0.5 g/kg和1 g/kg核桃青皮,与对照相比NO3--N含量分别降低46.26%和57.89%;NH4+-N含量分别增加370.05%和406.46%。核桃青皮有抑制土壤中脲酶活性、提高土壤硝酸还原酶活性和亚硝酸还原酶活性的作用,不同青皮用量处理间差异显著,与对照相比脲酶活性分别降低9.04%和15.73%,硝酸还原酶活性分别增加20.30%和73.81%,亚硝酸还原酶活性分别增加12.37%和40.82%。核桃青皮用量为1 g/kg土时效果明显。2核桃青皮、DCD和楝粉都能抑制NH4+-N向NO3--N的氧化过程,降低尿素在土壤转化过程中NO3--N含量而增加NH4+-N含量,与对照相比NO3--N含量分别下降58.50%、66.92%和55.30%,NH4+-N含量分别升高428.57%、814.28%和289.10%。核桃青皮、DCD和楝粉均有抑制土壤中脲酶活性,提高土壤中硝酸还原酶活性和亚硝酸还原酶活性的作用,与对照相比脲酶活性分别降低2.83%、10.42%和8.34%,处理间差异不显著;硝酸还原酶活性分别增加25.79%、77.79%和17.07%,处理间差异显著;亚硝酸还原酶活性分别增加32.10%、53.91%和26.32%,处理间差异显著。抑制效果DCD核桃青皮楝粉。3核桃青皮、DCD和楝粉有抑制土壤中氨氧化菌、促进反硝化菌繁殖的作用。试验初期各处理间有显著性差异,作用效果DCD核桃青皮楝粉,与对照相比氨氧化菌分别降低93.15%,93.55%和91.71%,反硝化菌分别增加673.33%,1040.72%和464.44%;培养后期各处理差异不显著。
[Abstract]:Walnut is a characteristic agricultural product in Shanxi Province, with an area of 400000 hectares. Walnut green peel is a thick green peel of walnut. Its main components are naphthoquinone and its glycosides, flavonoids and its glycosides, diaryl heptane, terpenes, organic acids and a series of compounds. Walnut green peel has allelopathic effect, which can inhibit nitrogen nitrification in soil and reduce N _ 2O emission. In addition, the application of walnut green peel into soil as organic matter can increase the content of soil organic matter. In this paper, simulated soil culture test was used to compare the effect of inhibition of nitrogen nitrification between walnut green peel and dicyandiamide (DCD) and azadirachta powder. The inhibition mechanism of nitrification on walnut green peel in enzymology and microbiology was discussed in order to provide scientific basis for walnut green skin as a biological nitrification inhibitor. The results showed that the content of NO3--N and the content of NH4-N in the soil were significantly decreased and increased by adding the green peel of walnut to the soil with the application of 1: 1 walnut green peel in the process of soil transformation. Adding 0.5 g/kg and 1 g/kg of walnut green peel decreased the content of NO3--N by 46.26% and 57.89%, respectively, and increased the content of NH4-N by 370.05% and 406.46%, respectively. Walnut green peel could inhibit urease activity, increase nitrate reductase activity and nitrite reductase activity in soil. Compared with the control, urease activity decreased by 9.04% and 15.73%, nitrate reductase activity increased 20.30% and 73.81%, nitrite reductase activity increased 12.37% and 40.82%, respectively. When the amount of walnut green peel was 1 g/kg, the effect was obvious. 2. Both walnut green peel DCD and azadirachta powder could inhibit the oxidation of NH4 -N to NO3--N, decrease the NO3--N content and increase NH4 N content during soil transformation. Compared with the control, the content of NO3--N decreased by 58.50% and the content of NH _ 4-N increased by 428.57 ~ 814.28% and 289.10% respectively. Both DCD and azadirachta powder could inhibit urease activity and increase nitrate reductase activity and nitrite reductase activity in soil. Compared with the control, the urease activity decreased by 2.83% and 8.34%, respectively. There was no significant difference between the treatments. The activity of nitrate reductase increased 25.79% and 17.07%, respectively, and the activity of nitrite reductase increased 32.10% 53.91% and 26.32%, respectively. The inhibitory effect of DCD powder of walnut peel. 3. 3 walnut peel DCD and Melia azedarach powder can inhibit ammonia-oxidizing bacteria in soil and promote the reproduction of denitrifying bacteria. At the beginning of the experiment, there were significant differences among the treatments, and the effect of DCD on pecan peel azadirachta powder was 93.15% and 91.71% lower than that of the control, respectively, and the denitrifying bacteria increased by 673.33 1040.72% and 464.44%, respectively, but there was no significant difference between the two treatments in the later stage of culture.
【学位授予单位】：山西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S664.1;S153

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