Effects of Cotton Straw Return to Field on Spatiotemporal Distribution of Soil CO2 in Oasis
The effects of cotton straw returned to field on soil CO2 concentration,flux and spatiotemporal distribution were conducted by using the closed chamber method and diffusion chamber technique in oasis.The results showed that the temporal variation of soil CO2 concentration and flux with the time was significant,their peak values occurred in July,and their minimums in October;compared to NS,the peak values of soil CO2 concentration and flux also occurred in May after cotton straw was returned to field.Vertically,soil CO2 concentration was increased with the increase of soil depth,but the effect of returning cotton straw on the vertical distribution of soil CO2 concentration was not significant.Over the measurement period,the mean values of soil CO2 concentration were 5 946.2,6 837.3,7 717.3 and 10 437.6 mg · kg-1,and those of soil CO2 flux were 110.22,136.84,140.75 and 169.47 mg · m-2 · h-1 under NS,HS,TS and DS,respectively.These indicated that cotton straw returned to field played an important role in soil CO2 concentration and flux,but soil CO2 concentration and flux were significantly higher in DS than in TS and HS (P ＜0.05).In addition,the correlation coefficients between soil CO2 concentration and flux were 0.3-0.6,0.68-0.72,0.72-0.77 and 0.85-0.88 under NS,HS,TS and DS,and they were increased with the increase of amount of cotton straw returned to field,that means soil CO2 flux depended strongly on soil CO2 concentration.Under current level of agricultural production,it was suggested to return total cotton straw to field in comprehensively evaluating the effect of different amounts of cotton straw returned to field.
oasiscottonstraw returned to fieldsoil CO2 concentrationsoil CO2 flux
国家科技期刊平台
NSTL
万方数据
维普
