中文摘要：

为了探讨保护性耕作对旱作农田土壤呼吸的影响,采用LI6400-09呼吸室在重庆北碚西南大学试验农场对平作（T）、垄作（R）、平作＋覆盖（TS）、垄作＋覆盖（RS）这4种处理下的西南紫色土丘陵区小麦/玉米/大豆套作体系中小麦作物生长季节的土壤呼吸及其水热生物因子进行了测定和分析. 结果表明,小麦生殖生长阶段农田土壤呼吸速率变化范围为1.100~2.508 μmol·（m2·s）-1,各处理的土壤呼吸速率差异显著,表现为RS〉R〉TS〉T. 各处理10 cm土层的土壤温度表现为T〉R〉TS〉RS. 土壤呼吸与土壤温度的关系符合指数函数,Q10值分别为1.25、1.20、1.31和1.26. 5 cm土层的土壤含水量高低排序为TS〉RS〉T〉R. 土壤水分与土壤呼吸以抛物线曲线拟合最好,说明存在土壤呼吸最强的土壤含水量点,本研究得出小麦生殖生长阶段在土壤含水量的响应阈值为14.80%~17.47%. 土壤动物中优势类群为弹尾目和螨目,与土壤呼吸存在一定相关性,对照处理和垄作下相关性高,而秸秆覆盖的处理土壤呼吸与土壤动物没有明显的相关性.

英文摘要：

In order to investigate the effect of conservation tillage on soil respiration in dry cropping farmland in southwest purple hilly region, the LI6400-09 respiratory chamber was adopted in the experiment conducted in the experimental field in Southwest University in Beibei, Chongqing. The respiration and the hydrothermal and biotic factors of soil were measured and analyzed during the growth period of wheat in the triple intercropping system of wheat/maize/soybean. There were four treatments including T （traditional tillage）, R （ridge tillage）, TS （traditional tillage＋straw mulching） and RS （ridge tillage＋straw mulching）, which were all in triplicates. The results indicated that the soil respiration rate changed in the range of 1.100-2.508 μmol·（m2·s）-1 during the reproductive growth stage of wheat. There were significant differences in soil respiration rate among different treatments, which could be ranked as RS〉R〉TS〉T. The soil temperature in the 10cm layer was ranked as T〉R〉TS〉RS. The relationship between soil respiration and soil temperature fitted well with an exponential function, in which the Q10 values were 1.25, 1.20, 1.31 and 1.26, respectively. The soil moisture in the 5cm layer was ranked as TS〉RS〉T〉R. The best fitting model between soil moisture and soil respiration was a parabolic curve, indicating the presence of soil moisture with the strongest soil respiration. The response threshold of wheat to soil moisture was 14.80%-17.47% during the reproductive stage. The dominant groups of soil animals were Collembola and Acarina, which were correlated with soil respiration to some extent. The correlation was high in the treatments T and R, ranged from 0.669-0.921, whereas there was no remarkable correlation in the other treatments.