| 保护性耕作下小麦田土壤呼吸及碳平衡研究 |
| 摘要点击 3015 全文点击 1288 投稿时间：2013-09-30 修订日期：2013-11-21 |
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| 中文关键词 根系生物量外推法 根排除法 土壤呼吸 作物生物量 保护性耕作 小麦 |
| 英文关键词 root biomass regression (RR) root exclusion (RE) soil respiration (Rs) biomass conservation tillage wheat |
| 作者 | 单位 | E-mail | | 张赛 | 西南大学农学与生物科技学院, 三峡库区生态环境教育部重点实验室, 南方山地农业教育部工程研究中心, 重庆 400716 | 532875132@qq.com | | 王龙昌 | 西南大学农学与生物科技学院, 三峡库区生态环境教育部重点实验室, 南方山地农业教育部工程研究中心, 重庆 400716 | wanglc2003@163.com | | 黄召存 | 西南大学农学与生物科技学院, 三峡库区生态环境教育部重点实验室, 南方山地农业教育部工程研究中心, 重庆 400716 | | | 贾会娟 | 西南大学农学与生物科技学院, 三峡库区生态环境教育部重点实验室, 南方山地农业教育部工程研究中心, 重庆 400716 | | | 冉春燕 | 西南大学农学与生物科技学院, 三峡库区生态环境教育部重点实验室, 南方山地农业教育部工程研究中心, 重庆 400716 | |
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| 中文摘要 |
| 为了研究小麦农田生态系统土壤碳排放与作物碳蓄积特征，采用LI6400-09在重庆北碚西南大学教学试验农场对平作（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生长季节的土壤呼吸及植株生长动态进行了观测. 利用根系生物量外推法（root biomass regression，RBR）和根排除法（root exclusion，RE）这2种方法比较分析根系呼吸对土壤总呼吸的贡献，并估算小麦农田碳收支状况. 结果表明，土壤呼吸介于0.62~2.91 μmol·（m2·s）-1，平均值为1.71 μmol·（m2·s）-1. T、R、TS、RS各处理日均土壤呼吸速率分别为1.29、1.59、1.99、1.96 μmol·（m2·s）-1，表现为T-2，地上部分生物量累计为51800.84、59563.20、66015.37、71331.63 kg·hm-2. 与对照相比，R、TS、RS这3个处理分别增产14.99%、27.44%和37.70%. RBR方法测得根系呼吸贡献为47.05%，根系呼吸速率在0.201~1.226 μmol·（m2·s）-1之间，RE法下则为53.97%. 在小麦生长初期农田表现为弱的碳源，拔节期开始随着小麦植株的生长，农田碳汇能力越来越强，在灌浆期达到最大，随后进入成熟期，农田又呈现出碳源特征. 小麦生长季T、R、TS、RS各处理总的碳收支分别为5924.512、6743.807、8350.741、8876.115 kg·hm-2，因此，以垄作和秸秆覆盖为主的保护性耕作能显著提高农田生态系统的碳汇能力，增汇幅度达13.83%~49.82%. |
| 英文摘要 |
| In order to study the characteristics of carbon sources and sinks in the winter wheat farmland ecosystem in southwest hilly region of China, the LI6400-09 respiratory chamber was adopted in the experiment conducted in the experimental field in Southwest University in Chongqing. The soil respiration and plant growth dynamics were analyzed during the growth period of wheat in the triple intercropping system of wheat-maize-soybean. Four treatments including T (traditional tillage), R (ridge tillage), TS (traditional tillage+straw mulching), and RS (ridge tillage+straw mulching) were designed. Root biomass regression (RR) and root exclusion (RE) were used to compare the contribution of root respiration to total soil respiration. The results showed that the average soil respiration rate was 1.71 μmol·(m2·s)-1 with a variation of 0.62-2.91 μmol·(m2·s)-1. Significant differences in soil respiration rate were detected among different treatments. The average soil respiration rate of T, R, TS and RS were 1.29, 1.59, 1.99 and 1.96 μmol·(m2·s)-1, respectively. R treatment did not increase the soil respiration rate significantly until the jointing stage. Straw mulching treatment significantly increased soil respiration, with a steadily high rate during the whole growth period. During the 169 days of growth, the total soil respiration was 2266.82, 2799.52, 3483.73 and 3443.89 kg·hm-2 while the cumulative aboveground biomasses were 51800.84, 59563.20, 66015.37 and 71331.63 kg·hm-2. Compared with the control, the yield of R, TS and RS increased by 14.99%, 27.44% and 37.70%, respectively. The contribution of root respiration to total soil respiration was 47.05% by RBR, while it was 53.97% by RE. In the early growth period, the carbon source was weak. The capacity of carbon sink started to increase at the jointing stage and reached the maximum during the filling stage. The carbon budget of wheat field was 5924.512, 6743.807, 8350.741, 8876.115 kg·hm-2, respectively. The results indicated that ridge tillage and straw mulching conservation tillage significantly improved the carbon sink in the wheat farmland ecosystem. |
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