CO2、CH4与N2O作为全球气候变化贡献较大的温室气体日益受到重视,而覆膜滴灌作为一种节水的田间农艺措施也受到广泛关注。笔者就土壤温湿度对土壤温室气体产生及排放的影响、覆膜滴灌造成土壤温湿度的改变及其对土壤温室气体排放的作用进行了综述。目前的研究成果表明:(1)土壤温度、湿度都通过影响土壤微生物菌群数量和活性、调节气体传输速率,对土壤温室气体产生和排放起作用;(2)土壤CO2排放速率与浅层地温正相关,CH4与N2O的产生都有一定的最适温度,而CH4的氧化与温度的关系呈多样性;(3)土壤湿度对CH4产生、氧化与N2O产生的作用都大于土壤温度,CH4氧化速率与土壤湿度呈负相关,而CO2与N2O的排放都有一个最佳的湿润范围;(4)覆膜良好的增温保湿效应、对气体传输的自然阻隔作用以及滴灌的局部湿润作用又会影响温室气体的产生和排放。最后总结提出了有待进一步展开和完善的几方面研究工作:如何确定和控制土壤湿润范围以减少温室气体排放,如何定量确定覆膜滴灌的综合效应,如何通过调控土壤CO2的排放以调控作物的生长过程。
CO2,CH4 and N2O have attracted increasing attention as great contributors to global warming.Mulched drip irrigation is also receiving wide interests as a water-saving agricultural technology.Research on the influence of soil temperature and moisture on production and emission of greenhouse gases(GHG),changes of soil temperature and moisture caused by mulched drip irrigation and their effects on emission of GHG were summarized in this paper.Research results demonstrated that:(1) soil temperature and moisture had an influence on production and emission of GHG by affecting soil microbial activity,soil aeration and gas transmission rate;(2) Emission rate of soil CO2 was positively related to topsoil temperature of superficial layer,the production of both CH4 and N2O had a certain optimum temperature,and the relation between the oxidation of CH4 and temperature was various;(3) Soil moisture's effect on production and oxidation of CH4 and the production of N2O was greater than soil temperature,rate of methane oxidation was negatively related to soil moisture,while the emission of CO2 and N2O had an optimum moisture range;(4) The temperature-increasing and humidity-preserving effect,the barrier effect of gaseous transmission caused by mulch and the partially soil wetting pattern under drip irrigation would have an influence on the production and emission of GHG.Inthe end,several relevant research aspects left to be developed and perfected were summarized and presented:how to reduce GHG emission by confirming and controlling the wetting percentage of soil;how to quantify the combined effect of mulch and drip irrigation;how to regulate and control crops'process of growth through regulating soil CO2 emission.