| No-tillage is an important farming technique which conserves soil, fertilization and water of the farmland. It is also known as the effective farming measure to fix soil, conserve water, save energy and reduce emission of CO2, and keep high and stable yield in north china. Taking the Wuchuan County in Inner Mongolia Autonomous Regional for example, this research analysed the change characteristics of ecological factors and the emission characteristics of greenhouse gases in the farmland soil using different farming methods and no-till fertilization measures. Field experiment and laboratory tests were conducted during the two-year study period. The results were as follows:1. The soil CO2 emission was significantly different and subject to the seasonal changes; the CH4 and N2O emissions were not obvious with the seasonal changes. The CH4 emission flux almost appeared to be negative and presented as "absorption". Comparing with stubble covering, no-tillage reduced the CO2 emission, the CH4 absorption and the synthesized greenhouse effect while it may increase the N2O emissions. Straw mulch treatment showed more significant influence on the greenhouse gases emissions than stubble height. The fertilization treatment increased the emissions of CO2, N2O, and the absorption of CH4, comparing with no fertilization in the no-tillage fertilizer experiment. The single nitrogen fertilizer treatment showed more influence on increasing the greenhouse gases emissions. The N-P fertilizer and N-P-K fertilizer application combined treatments showed even more influence on the CO2 emissions and the CH4 absorption; and of these treatments on the N2O emissions, the influence was lower than the single nitrogen fertilizer treatment. The phosphatic fertilizer treatment and the potassic fertilizer treatment showed less influence on the emission of greenhouse gases. The comprehensive effect of the greenhouse gases emission was majorly dominated by the CO2 flux, and it was little affected by the CH4 flux and N2O flux.2. No-tillage was effective for increasing the soil nutrient content and changing the soil moisture and temperature. No-tillage and stubble mulching treatments increased the soil moisture content and reduced the soil temperature comparing with conventional tillage. In no-tillage treatment, the average soil moisture content of three soil layer (0-10cm,10-20cm and 0-20cm) was 86.95%,46.62% and 66.18% higher than conventional tillage treatment, respectively, the average soil temperature in 10cm and 20cm depth were 2.92℃and 2.02℃lower than conventional tillage, respectively; the soil organic carbon, total nitrogen and, total phosphorus were significantly or highly significantly higher than traditional farming in 0-10cm layer, but close to 0-20cm layer. The no-tillage fertilization experiment showed that the application of nitrogen fertilizer lowered in the soil water content but increased in the total nitrogen content, while soil organic carbon and total phosphorus had no significant change; the phosphate fertilizer applied into the soil making an increase of total phosphorus content, but had no significant effect on soil moisture, organic carbon and total nitrogen; the application of potash fertilizer had no significant effect on soil moisture, organic carbon, total nitrogen and total phosphorus; fertilization had-little influence to soil temperature.3. The soil enzyme activity had been changed regularly in different season. Experiment of different tillage methods showed that the soil enzyme activity in the no-tillage with stubble covering treatment was significantly higher than that in the conventional tillage treatment. The effect by no-tillage and covering was higher than those by increasing stubble height on improving the soil enzyme activity. The no-tillage fertilizer treatment can improve the soil enzyme activity. For the activity of urease, alkaline phosphatase and saccharase, the nitrogen fertilizer treatment had the most significant effect, followed by the phosphate fertilizer treatment; the potash fertilizer treatment had no obvious effect. For the activity of hydrogen peroxide, the potash fertilizer treatment showed more influence than other treatment; the nitrogen fertilizer treatment showed no significant effect. The N-P fertilizer and N-P-K fertilizer application combined treatments had larger effect on the soil enzyme activity than the single application of N, P or K fertilizer.4. The result of different tillage method experiments indicated that the soil microbial biomass C, microbial biomass N, microbial biomass P and the microbial quotient was significantly increased under the treatment of no-tillage with stubble covering, comparing with conventional tillage methods. The effect of straw coverage treatment was better than the stubble height treatment on increasing the soil microbial biomass and microbial quotient. The soil microbial biomass C, N, P and the microbial quotient were higher under the no-tillage and fertilizer treatment than the no-tillage without fertilizer treatment. The largest increase of the microbial biomass C, N and microbial quotient was under the nitrogen fertilizer treatment. The largest increase of the microbial biomass P was under the phosphate fertilizer treatment. The potash fertilizer treatment was little effected to the microbial biomass and microbial quotient. The N-P fertilizer and N-P-K fertilizer application combined treatments had larger effect on the microbial biomass and microbial quotient than the single application of N, P or K fertilizer.5. The emissions of soil greenhouse gases are subject to the soil physical and chemical characteristics, enzyme activities, microbial biomass and many others. The research results showed that the soil temperature, moisture, nutrients, enzymes and soil microbial biomass were closely related to the emissions of soil greenhouse gases. In detail, the significant positive correlation was observed between the soil temperature (0-10cm depth) and the emissions of CO2, CH4 and N2O; the same was between the organic carbon and those three gases. The soil moisture of two different soil layer (0-10cm depth and10-20cm depth) and the total-N was significantly (or highly significant) positive correlated with the emissions of CO2, CH4 and N2O. The total-P in all soil layers was not obvious correlated with the emissions of the soil greenhouse gases. There were significant positive correlations between the two soil enzyme (urease, saccharase) activities and the emissions of soil greenhouse gases. While the correlation was not obvious on alkaline phosphatase activity and catalase activity; the microbial biomass C, microbial biomass N and microbial quotient was very significant or obvious positive correlations with the emissions of CO2, CH4 and N2O; the microbial biomass P was significant positive correlation with the CO2 emissions but was not obvious correlated with the emission flux of CH4 and N2O.The influence of no-tillage on field experiment and greenhouse gases emissions is a long and slow process. Variation characteristics are different depend on the length of study time. The exploration of soil properties and long-term emission of soil greenhouse gas needed to be improved as the experiment lasted only two years.
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