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为了评价氮肥对土壤生态环境的效应,通过大田试验,应用微量热技术研究了麦田土壤不同土层中微生物热代谢活性的变化以及在不同施氮量处理下微生物活性分布的情况。结果表明,随着土层的加深,功率时间曲线由陡变缓;同时施肥也改变了微生物的活性,长期不施肥处理与施肥处理的0~30 cm土层的微生物活性差异不大,但随着土层的加深不施肥处理微生物活性急剧下降;而施氮180 kg/hm2处理下0~30 cm土层与30~60 cm土层的微生物活性相近,施氮300 kg/hm2处理下30~60 cm土层和60~90 cm土层的微生物活性相差不大。相关性分析显示,施氮量与微生物生长速率k呈显著负相关。可见,不同土层有着不同的微生物活性,不同施氮处理改变了微生物的垂直分布情况。
In order to evaluate the effect of nitrogen fertilizer on soil ecological environment, the changes of microbial metabolic activity in different soil layers of wheat field and the distribution of microbial activity under different nitrogen application rates were studied by field experiments. The results showed that with the deepening of the soil layer, the power-time curve slowed down steeply. Simultaneously, fertilization changed the activity of microorganisms. There was no significant difference in the microbial activity between 0-30 cm soil layer without fertilization and fertilization for a long time. However, Soil microbial activity decreased rapidly with no soil fertilization treatment. However, the activities of microorganisms in 0-30 cm soil layer and 30-60 cm soil layer under nitrogen application of 180 kg / hm2 were similar to those of 30-60 cm soil layer under nitrogen application of 300 kg / hm2 cm soil layer and 60 ~ 90 cm soil layer microbial activity or less. Correlation analysis showed that there was a significant negative correlation between nitrogen application rate and microbial growth rate k. Visible, different soil layers have different microbial activity, different nitrogen treatment changed the vertical distribution of microorganisms.