Li Jiao, Tian Dong, Huang Rong, Xu Guo-Xin, Li Jia-Cheng, Gao Ming, Wang Zi-Fang
College of Resource and Environment, Southwest University, Chongqing 400715, China.
Huan Jing Ke Xue. 2018 Sep 8;39(9):4338-4347. doi: 10.13227/j.hjkx.201712051.
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. 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 (<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) and BC (10.75 t·hm) 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).⑤BC treatment increased carbon productivity (C) in both seasons, while the economic (C) and ecological benefits(C) 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.
在油菜-玉米轮作种植系统下，研究了不同秸秆和生物炭施用对农田生态系统碳平衡的影响。该研究探讨了添加秸秆和生物炭对土壤碳固存的影响。在中国重庆紫色土土壤肥力与肥料效益国家监测站进行了田间试验。设置了5种处理，即对照（CK，不添加有机物料）、仅秸秆（CS）、秸秆与微生物（CSD）、一半秸秆一半生物炭（CSBC）和仅生物炭（BC），随后监测土壤总碳的累积排放量。基于田间试验和调查数据，分析了秸秆和生物炭施用后土壤呼吸、土壤碳库、作物碳库的碳排放、碳固存以及农业投入成本的经济和环境效益。主要结果如下：①两个种植季节中，各处理土壤碳累积排放量均高于CK，且CS、CSD与CK之间的差异显著（<0.05）。②与CK相比，秸秆和生物炭处理均提高了作物产量（提高了1.49%-3.92%），作物净初级生产力（NPP）提高了4.44%-17.90%。两个季节中CSD处理的产量和NPP最高。③所有不包括CK的处理在两个季节的净碳固存均为正值，表明存在碳汇效应。CSD（9.05 t·hm）和BC（10.75 t·hm）处理的净碳固存最高。BC处理的碳排放最低，排放量比CK低62.69%-81.86%。④在油菜种植季节，CS处理的产投比最高。仅施用生物炭降低了产投比，但增加了碳交易收入（466.95-561.22元·hm）。⑤BC处理在两个季节均提高了碳生产力（C），而BC处理的经济（C）和生态效益（C）显著低于其他处理。添加秸秆增加了经济和生态效益；然而，添加生物炭降低了这些效益。
