| 秸秆及生物炭还田对油菜/玉米轮作系统碳平衡和生态效益的影响 |
| 摘要点击 1721 全文点击 670 投稿时间：2017-12-07 修订日期：2018-03-10 |
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| 中文关键词 秸秆 生物炭 紫色土 碳平衡 碳效益 |
| 英文关键词 straw biochar purple soil carbon balance carbon benefit |
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| 中文摘要 |
| 在油菜/玉米轮作下，研究不同秸秆与生物炭还田方式对农田生态系统碳平衡和收益的影响，阐明秸秆和生物炭还田的固碳作用.在重庆国家紫色土肥力与肥料效益长期监测基地，通过油菜和玉米两季作物田间定位试验，设置了常规施肥（CK）、秸秆还田（CS）、生物炭还田（BC）、秸秆+速腐剂还田（CSD）、秸秆+生物炭1：1还田（CSBC）5个处理，测定了秸秆与生物炭还田下土壤碳累积排放量，并结合实地调研数据，从土壤呼吸碳排放、土壤碳库及作物碳库角度兼顾考虑农业成本投入，分析了秸秆与生物炭还田下农田生态系统碳排放、碳固定、碳汇效应和经济环境效益.结果表明：①两季作物的土壤碳累积排放量均高于对照（CK），其中秸秆直接还田（CS）处理和秸秆+速腐剂还田（CSD）处理显著（P<0.05）；②与CK对比，秸秆及生物炭还田均能提高两季作物产量与生态系统净初级生产力（NPP），增产1.49%~3.92%，NPP提高了4.44%~17.90%，且秸秆+速腐剂处理（CSD）的两季作物产量与NPP均为最大；③各处理（除CK外）均为系统净固碳量正值，表现为"碳汇"；在油菜季和玉米季两季中，系统净固碳量最高的分别为秸秆+速腐剂还田（CSD，9.05 t·hm-2）和生物炭还田（BC，10.75 t·hm-2）处理，而碳排放量最低的均是生物炭（BC）处理，比CK减少62.69%~81.86%.④油菜季的秸秆直接还田（CS）处理的两季作物产投比最高，而两季作物的BC处理均会降低产投比，但其碳排放交易量最高（466.95~561.22元·hm-2）.⑤两季作物的BC处理均会提高碳生产力（CP），而BC处理的经济效益（CJ）与生态效益（CE）均显著低于其他处理.秸秆直接还田增加了系统的经济效益和生态效益，而生物炭还田降低了系统的经济效益和生态效益. |
| 英文摘要 |
| The effects of different straw and biochar applications on the carbon balance of a farmland ecosystem were studied under a rape-maize rotation planting system. The study explored impact of straw and biochar addition on soil carbon sequestration. A field experiment was carried out at the National Monitor Station of Soil Fertility and Fertilizer Efficiency of Purple Soils (Chongqing, China). Five treatments, i.e., control (CK, no organic material), straw only (CS), straw and microorganism (CSD), half straw and half biochar (CSBC), and biochar only (BC), were applied. In-situ cumulative emissions of soil total carbon were subsequently monitored. Based on field experiment and survey data, carbon emissions, carbon sequestration, and and economic and environmental benefits were analyzed for soil respiration, soil carbon pool, crop carbon pool, as well as the cost of agricultural inputs after straw and biochar application. The main results were:①Accumulative emissions of soil carbon during two planting seasons were all higher with treatment than in CK, and the differences between CS, CSD, and CK were significant (P<0.05). ②Compared with CK, both straw and biochar treatments increased crop yield (by 1.49%-3.92%) and crop net primary productivity (NPP) increased by 4.44%-17.90%. Largest yields and NPP during both seasons were achieved with CSD.③Net carbon sequestration was positive during both seasons in all treatments without CK, indicating a carbon sink effect. The highest net carbon sequestration was obtained with CSD (9.05 t·hm-2) and BC (10.75 t·hm-2) treatments. The lowest carbon emissions were obtained with the BC treatment, with emissions 62.69%-81.86% lower than CK. ④The highest production to cost ratio was obtained with CS treatments during the rape planting season. Application of only biochar reduced the production to cost ratio but increased the carbon trading income (466.95-561.22 yuan·hm-2).⑤BC treatment increased carbon productivity (CP) in both seasons, while the economic (CJ) and ecological benefits(CE) of BC treatment were significantly lower than with other treatments. The addition of straw increases economic and ecological benefits; however, addition of biochar reduces such benefits. |
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