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土壤微生物是表征土壤质量变化的敏感指标之一。借助长期定位试验,采用磷脂脂肪酸分析方法研究了3种种植方式(玉米(Zeamays)连作、玉米非连作和撂荒)对土壤微生物群落组成的影响。结果表明,在不同的种植方式下,土壤微生物群落组成有明显的差异。玉米连作的土壤中总磷脂脂肪酸和细菌磷脂脂肪酸含量最低,分别为33.12nmol·g-1和18.09nmol·g-1。非连作的土壤真菌磷脂脂肪酸和真菌/细菌分别为0.61nmol·g-1和3.06%,显著低于撂荒和连作(p<0.05),非连作方式下,革兰氏阳性细菌/革兰氏阴性细菌增大。撂荒土壤的总磷脂脂肪酸和细菌磷脂脂肪酸分别为42.98和24.68nmol·g-1,高于耕作处理。同时,在撂荒方式下,革兰氏阳性细菌和革兰氏阴性细菌的含量增加,革兰氏阳性细菌/革兰氏阴性细菌降低。主成分分析结果表明:耕作处理(玉米连作和非连作)分布第一主成分负方向上,第一主成分得分系数分别为-2.48和-1.84;撂荒分布第一主成分正方向上,第一主成分得分系数为2.31,与连作和非连作差异显著(p<0.05)。冗余分析(RDA)表明:土壤pH、总氮、有效磷和土壤>0.25mm水稳性团聚体含量与磷脂脂肪酸呈正相关,并且土壤pH和土壤>0.25mm水稳性团聚体含量对土壤微生物群落的影响最大。
Soil microorganisms are one of the sensitive indicators of soil quality changes. Using long-term experiment, the effects of three planting methods (corn planting (Zeamays), maize unincorporated and fallowing) on the composition of soil microbial community were studied by phospholipid fatty acid analysis. The results showed that there were obvious differences in the composition of soil microbial community under different planting methods. The contents of total phospholipid fatty acid and bacterial phospholipid fatty acid in the continuous cropping maize were the lowest, which were 33.12nmol · g-1 and 18.09nmol · g-1, respectively. The non-interlinked soil fungal phospholipid fatty acids and fungi / bacteria were 0.61nmol · g-1 and 3.06%, respectively, which were significantly lower than those of wild and continuous cropping (p <0.05). Gram-positive bacteria / Gram- Bacteria increase. Total phosphatidic fatty acid and bacterial phospholipid fatty acids in wasteland were 42.98 and 24.68nmol · g-1, respectively, which were higher than those of tillage. At the same time, Grampositive and Gram-negative bacteria levels increased with Grampositive mode and Gram-positive / Gram-negative bacteria were reduced. Principal component analysis showed that the coefficients of the first principal component were -2.48 and -1.84 respectively in the negative direction of the first principal component of tillage processing (continuous cropping and non-continuous cropping), while in the positive direction of the first principal component, the first principal The score of component score was 2.31, which was significantly different from that of continuous cropping and non-continuous cropping (p <0.05). Redundancy analysis (RDA) showed that soil pH, total nitrogen, available phosphorus and water> 0.25mm water stable aggregates content positively correlated with phospholipid fatty acids, and soil pH and soil> 0.25mm water stable aggregates content affected soil microorganisms The community has the greatest impact.