不同耕作措施下旱作麦田CO2排放速率与土壤水热关系分析

摘要

In order to find out the effects of conservation tillage on the emission of CO2 fluxes, the relationships of soil respiration with soil temperature and soil water in arid areas, a short term experiment was conducted with 6 treatments including deep tillage (T), deep tillage with straw application (TS), rotary tillage (RT), rotary tillage with straw application (RTS), no tillage (NT) and no tillage with straw application (NTS) in Yangling Shaanxi, P. R China. Data was recorded and analyzed.The results showed that the CO2 emission fluxes had obvious seasonal variations. The order of CO2 fluxes emission was TS＞T＞RTS＞RT＞NTS＞NT, and the differences of these different treatments were highly significant at 0. 01 level. The emissions of CO2 fluxes from the straw treatments were higher than those ofno straw treatments. The relationship of soil. respiration and soil temperature also showed significant positive correlation. Treatments of T, RT and NT had the best correlation at 15, 5 and 10 cm soil layer. Their correlation coefficients were 0.899, 0.779 and 0. 934. While no significant correlation was recorded between soil respiration and soil water.%采用定位试验,系统研究翻耕(T)、翻耕+秸秆还田(TS)、旋耕(RT)、旋耕+秸秆还田(RTS)、免耕(NT)、免耕+秸秆覆盖(NTS)6种不同耕作措施下土壤CO2排放速率的季节变化规律,分析土壤CO2排放速率与土壤水热的相互关系.结果表明,CO2排放速率有明显的季节变化规律,均表现为冬季低夏季高;整个生长季平均排放速率为TS>T>RTs>RT>NTS>NT,并且T、RT、NT 3种耕作措施之间差异均达到极显著水平(P<0.01);TS、RTS、NTS 3种有秸秆耕作措施的CO2排放速率均高于相应的T、RT、NT 3种无秸秆耕作措施,且T与TS之间差异达到极显著水平;土壤温度和CO2排放速率表现为极显著正相关,T、RT和NT分别与15、5、10 cm土层温度相关性最大,相关系数分别为0.899、0.779、0.934;土壤含水量与CO2排放速率未表现出显著相关性.