为了探讨保护性耕作对旱作农田土壤呼吸的影响，采用LI6400XT便携式光合作用测量系统自带的土壤呼吸室（6400-09）在重庆北碚西南大学试验农场对传统耕作（T，traditional farming）、垄作（R，ridge planting）、传统耕作+秸秆覆盖（TS，traditional farming straw mulching）、垄作 秸秆覆盖（RS，ridge planting straw mulching）、传统耕作 秸秆覆盖 秸秆速腐剂（TSD，traditional farming straw mulching decomposing agent）、垄作 秸秆覆盖 秸秆速腐剂（RSD，ridge planting straw mulching decomposing agent）6种处理下的西南紫色土丘陵区小麦/玉米/大豆套作体系中作物生长季节的土壤呼吸及其水热因子进行了测定和分析。结果表明，6种处理中土壤呼吸速率的季节变化明显，各处理日均土壤呼吸速率差异显著。其中在小麦-大豆条带，小麦土壤呼吸速率均值为1.53 μmol m-2 s-1，大豆土壤呼吸速率日均值为4.10 μmol m-2 s-1，各处理日平均土壤呼吸速率大小排序为T
To investigate effects of tillage pattern on soil respiration in dry cropping farmlands in purple soil hilly region in Southwest China, an LI6400-XT portable photosynthesis measurement system equipped with a soil respiratory chamber (6400-09) was used in an experiment conducted in the experimental field of the Southwest University in Beibei, Chongqing. Respiration and hydrothermal factors of the soils under the same wheat/corn/soybean triple intercropping system, but different tillage patterns were measured and analyzed during the crop growing period. The tillage patterns or treatments were coded as T (traditional tillage), R (ridge tillage), TS (traditional tillage + straw mulching), RS (ridge tillage straw mulching), TSD (traditional tillage straw mulching decomposing inoculants), and RSD (ridge tillage straw mulching decomposing inoculants) and each had 3 replicates. Results show that soil respiration rate varied significantly with the season and from treatment to treatment as well. The daily mean soil respiration rate under wheat and soybean in the wheat-soybean row was 1.53 μmol m-2 s-1 and 4.10 μmol m-2 s-1, respectively and varied between treatments, displaying an order of T < R < TS < TSD < RS < RSD. In the blank-corn-black row, the daily mean soil respiration rate of the soil under corn reached 2.56 μmol m-2 s-1, ranging between those under wheat and soybean, and varied between treatments, displaying an order of R < T < RS < TS < RSD < TSD. The total soil respiration rate of the field under the intercropping system was 1.54～2.13 g m-2 and varied between treatments, displaying an order of T < R < RS < TS < TSD < RSD. The experiment also shows that soil temperature and soil moisture content were the two major factors affecting soil respiration, explaining 28.9 %~53.7 % and 13.7 %~42 % of its seasonal variation. Regression analysis of the relationship between soil respiration and soil hydrothermal factors reveals that exponential equation (Rs =0.311e 0.095T) fits well the relationship between soil respiration and soil temperature at 10 cm in soil depth and the temperature sensitivity index (Q10) of soil respiration was 2.25~2.69. However, the relationship between soil respiration and soil moisture content can be best described with a parabolic function. The threshold of soil moisture soil respiration responds to was 14.94%. In short, the findings may serve as reference to the study on rules of the variation of soil respiration in the farmland ecosystem and mechanisms for controlling its affecting factors, and are of some important significance to global carbon budgeting and assessment of regional carbon sources and pools.
张 赛,王龙昌,张晓雨,周航飞.紫色土丘陵区保护性耕作下旱地土壤呼吸及影响因素[J].土壤学报,2014,51(3):520-530. DOI:10.11766/trxb201307150338 Zhang Sai, Wang Longchang, Zhang Xiaoyu, Zhou Hangfei. Respiration of upland soil under conservation tillage in purple hilly regions and its influencing factors[J]. Acta Pedologica Sinica,2014,51(3):520-530.复制