在当前气候变化情景下,基于T-FACE(temperature-free air carbon dioxide enrichment)平台升高温度和CO_2浓度,连续3 a在小麦生长季对太湖地区典型土壤乌栅土耕作层中无机氮素的动态变化进行了研究。结果表明:在小麦3个生长季内土壤中NH_4~+-N的含量表现为先降低后升高;温度升高、CO_2浓度升高和CO_2浓度与温度同时升高的交互作用会导致土壤中NH_4~+-N含量降低,并且时间越长,影响效果越明显;在小麦3个生长季内土壤中NO_3~--N的含量没有明显变化规律;CO_2浓度升高和CO_2浓度与温度同时升高的交互作用也能降低土壤中NO_3~--N的含量;温度对土壤中NO_3~--N含量的影响没有显著规律性;常规处理和CO_2浓度升高处理的土壤中NH_4~+-N和NO_3~--N的含量有显著和极显著相关关系,相关系数分别为0.538(p<0.05),0.725(p<0.01)。
英文摘要:
Based on T-FACE platform to elevate the temperature and CO_2 concentration under current climate change scenarios,the inorganic nitrogen contents in soils were measured to investigate the variation tendency in plough layer of the typical soil(Wushan soil)in Taihu region in wheat growing season for three consecutive years.The experimental results showed that:The soil NH_4~+ -N content increased at first and then decreased in the three wheat growing seasons.The temperature elevated,CO_2 concentration elevated and the interaction of CO_2 concentration and temperature elevated led to the NH_4~+ -N content decreased and the effect was stronger with time.The soil NO_3~- -N content had no significant variation in the three wheat growing seasons.The CO_2 concentration elevated and the interaction of CO_2 concentration and temperature elevated could also decrease the soil NO_3~- -N content.The NO_3~- -N content showed no clear variation under elevating temperature treatment.The soil NH_4~+ -N and NO_3~- -N contents under the ambient and CO_2 concentration elevated treatments had significant correlations,and the correlation coefficients were 0.538(p<0.05)and 0.725(p<0.01)respectively.