耕作方式对潮土碳氮磷转化相关微生物学性状的影响

In order to evaluate soil fertility and quality under different tillage management in north China from the soil microbiology point of view, a long-term stationary field experiment on no-tillage practice for maize-wheat rotation farming ecosystem in the Fengqiu Agro-ecological Experiment Station, Chinese Academy of Sciences, was performed to investigate the effects of tillage management on the contents of carbon (C), nitrogen (N), and phosphorus (P), and the related microbiological characteristics in fluvo-aquic soil. The experiment included three treatments: conventional tillage (CT), no tillage (NT), and alternating tillage (AT, tillage in the wheat season and no tillage in the maize season). Compared to the CT treatment, the NT and AT treatments had no significant effects on soil pH, the contents of total N, total P, mineral N, and available P, the microbial biomasses of C, N, and P, the soil basal respiration, or the microbial metabolic quotient after 3-year continuous management. Nevertheless, the NT treatment significantly increased (P < 0.05) soil organic C content, the activities of 4 key enzymes (dehydrogenase, invertase, urease, and alkaline phosphatase), and the microbial metabolic activity. Although the AT treatment did not influence soil urease activity, it tended to increase all the other 5 parameters. It suggested that NT conserves microbial metabolic activity and promotes soil nutrient transformation, while the positive influences of AT are relatively lower.