| N2O is an important greenhouse gas, although it is a kind of trace gases, but it has the effect of warming resulting from CO2 and CH4 than the number of large and stay in the atmosphere for a long time. N2O can not only damage to the ozone layer, but also global warming. N2O sources and sinks of the global situation is not particularly clear, there are a number of unknown sources and sinks has not been found between sources and sinks of a serious imbalance.Test in October 2007 to October 2008, in Shandong Province, Yucheng Comprehensive Experimental Station using static chamber / gas chromatography typical North China Plain farmland plants and soil N2O flux. Pilot study of winter wheat and summer maize crop in three fields in spring soybean plants and soil N2O flux diurnal and seasonal changes and changes in the characteristics of an analysis of ground temperature, soil moisture and available nitrogen (NO3--N and NH4+-N) content and the relationship between soil N2O fluxes and to study the impact of the four factors on the soil of the combined effects of N2O flux. The main research results are as follows:(1) In the crop growing season, the winter wheat and summer crops of corn and soybean fields in three soil N2O emissions for the average flux: 75,36.3, 8.4μg ? m-2 ? h-1 ,7-9 month on the average soil N2O emissions: Wheat Field> maize> soybean fields, the order in line with the whole growth period. Corn, soybean fields, wheat fields, wheat plants in soil are the source of N20, agricultural soils are the source of N2O emissions. Maize plants and soybean plants are sinks N2O.(2) In addition to soybean, the winter wheat and summer maize, two crops of soil N2O flux fields have shown clear signs of seasonal changes, the main performance of the average flux for the winter low and summer high. Fertilization on soil emissions of N2O fluxes have greater impact on winter wheat and summer corn, post-fertilization fluxes in both the peak discharge.Three types of crop fields have the regularity of soil N2O fluxes and non-regularity of diurnal variation in two forms. Winter wheat and summer maize field in a short period of time after fertilization, soil N2O fluxes higher diurnal variation showing a clear and obvious double-peak curve, and have a high day and low night law; in fertilization than before and after fertilization long-term changes in soil N2O fluxes on a lower diurnal variation was not obvious. Soybean field soil N2O flux is generally low, no diurnal variation.(3) Winter wheat (remove the impact of the fertilization) 5cm soil temperature and soil N2O fluxes have a certain relevance, reach a significant level of 0.01, the related equation is Y=1.7175X+6.0192;summer maize (remove the impact of the fertilization) 5cm soil temperature and soil N2O fluxes have a certain relevance, reach a significant level of 0.01, the related equation is Y=2.269e0.1037X.(4) Winter wheat (remove the impact of the fertilization) 5cm water content and soil N2O fluxes have a certain relevance, reach a significant level of 0.01, the related equation is Y=1.5735X-9.3105;summer maize (remove the impact of the fertilization) 5cm water content and soil N2O fluxes have a certain relevance, reach a significant level of 0.01, the related equation is Y=0.8059X-3.4025;soybean 5cm water content and soil N2O fluxes have a certain relevance, reach a significant level of 0.01, the related equation is Y=0.6145X-6.7363.(5) Winter wheat,summer corn field soil N2O flux to remove the impact of the fertilization,5cm temperature(X1) soil moisture(X2) and available nitrogen NO3--N (X3)and NH4+-N(X4)content toN2O fluxes of soil to reach the combined effects of a significant level(P<0.001),Derived fitted equation:Y= -35.72 + 1.53X1 +1.47X2 + 1.86X3 + 11.3X4.(6) Winter wheat leaf area index and N2O fluxes have obvious correlation , and to achieve a significant level of 0.05. Derived equations for Y=-5.2214X2+36.075X-21.67.
|
PDF Full Text Request