State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China.
College of Agricultural Engineering, Hohai University, Nanjing, People's Republic of China.
Environ Sci Pollut Res Int. 2019 Mar;26(8):8303-8311. doi: 10.1007/s11356-019-04326-8. Epub 2019 Jan 31.
The addition of biochar has been reported as a strategy for improving soil fertility, crop productivity, and carbon sequestration. However, information regarding the effects of biochar on the carbon cycle in paddy fields under water-saving irrigation remains limited. Thus, a field experiment was conducted to investigate the effects of biochar addition on the net ecosystem exchange (NEE) of CO and soil organic carbon (SOC) content of paddy fields under water-saving irrigation in the Taihu Lake region of China. Four treatments were applied: controlled irrigation (CI) without biochar addition as the control (CA), CI with biochar addition at a rate of 20 t·ha (CB), CI with biochar addition at a rate of 40 t·ha (CC), and flooding irrigation (FI) with biochar addition at a rate of 40 t·ha (FC). Biochar addition increased rice yield and irrigation water use efficiency (IWUE) by 24.0-36.3 and 33.4-42.5%, respectively, compared with the control. In addition, biochar addition increased the NEE of CI paddy fields. The average NEE of paddy fields under CB and CC was 2.41 and 30.6% higher than that under CA, respectively. Thus, the increasing effect of biochar addition at a rate of 40 t·ha was considerably better than those of the other treatments. Apart from biochar addition, irrigation mode was also identified as an influencing factor. CI management increased the NEE of paddy fields by 17.6% compared with FI management. Compared with CA, CB increased total net CO absorption by 10.0%, whereas CC decreased total net CO absorption by 13.8%. Biochar addition also increased SOC, dissolved organic carbon, and microbial biomass carbon contents. Therefore, the joint regulation of biochar addition and water-saving irrigation is a good technique for maintaining rice yield, increasing IWUE, and promoting soil fertility. Furthermore, when amended at the rate of 20 t·ha, biochar addition will be a good strategy for sequestering carbon in paddy fields.
生物炭的添加已被报道为一种提高土壤肥力、作物生产力和碳固存的策略。然而，关于节水灌溉下稻田生物炭对碳循环影响的信息仍然有限。因此，在中国太湖地区进行了一项田间试验，以研究生物炭添加对节水灌溉下稻田净生态系统交换（NEE）和土壤有机碳（SOC）含量的影响。试验共设置了 4 种处理：不添加生物炭的控制灌溉（CI）作为对照（CA），添加 20 t·ha 的生物炭（CB），添加 40 t·ha 的生物炭（CC）和添加 40 t·ha 的生物炭的淹水灌溉（FI）（FC）。与对照相比，生物炭添加分别将水稻产量和灌溉水利用效率（IWUE）提高了 24.0-36.3%和 33.4-42.5%。此外，生物炭添加增加了 CI 稻田的 NEE。CB 和 CC 处理下的稻田 NEE 平均比 CA 处理分别高出 2.41%和 30.6%。因此，添加 40 t·ha 生物炭的效果明显优于其他处理。除了生物炭添加外，灌溉方式也是一个影响因素。与淹水灌溉相比，CI 管理增加了稻田的 NEE 17.6%。与 CA 相比，CB 增加了 10.0%的总净 CO 吸收，而 CC 则减少了 13.8%。生物炭添加还增加了 SOC、溶解有机碳和微生物生物量碳的含量。因此，生物炭添加和节水灌溉的联合调控是维持水稻产量、提高 IWUE 和促进土壤肥力的好技术。此外，当添加率为 20 t·ha 时，生物炭添加将是稻田固碳的一个好策略。
