State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China; Changshu Agro-ecological Experimental Station, Chinese Academy of Sciences, Changshu 215555, China.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Changshu Agro-ecological Experimental Station, Chinese Academy of Sciences, Changshu 215555, China.
Sci Total Environ. 2017 Sep 1;593-594:347-356. doi: 10.1016/j.scitotenv.2017.03.159. Epub 2017 Mar 27.
Biochar and nitrification inhibitors are increasingly being proposed as amendments to improve nitrogen use efficiency (NUE). However, their effects on soil denitrification and the major N loss in rice paddies over an entire rice-growing season are not well understood. In this study, using intact soil core incubation combined with N/Ar technique, the impacts of biochar and a nitrification inhibitor (Ni), 2-chloro-6-(trichloromethyl)-pyridine, on rice yield and soil denitrification, as well as ammonia (NH) volatilization, were investigated over two rice-growing seasons in the Taihu Lake region of China. Field experiments were designed with four treatments: N0 (no N applied), N270 (270kg N ha applied), N270+C (25tha biochar applied) and N270+Ni (2-chloro-6- [trichloromethyl] -pyridine, 1.35kghaN applied). Compared with single application of N fertilizer alone (N270), biochar (N270+C) and Ni (N270+Ni) applications increased rice yields by 4.2-5.2% and 6.2-7.3%, respectively. The cumulative N-N and NH-N losses in different treatments varied from 11.9 to 21.8% and from 11.5 to 22.0% of the applied N, respectively. Compared with the single application of N fertilizer, the Ni application increased total NH emission by 4.0-20.6% and significantly decreased total N-N emission by 9.7-19.4% (p<0.05), while the biochar application increased total NH and N-N emissions by 8.6-17.9% and 3.3-9.7%, respectively. Overall, the biochar application resulted in an 11-15% higher net gaseous N than the Ni application. Although the biochar application may increase the rice yield and consequently the plant N uptake, it also promoted N loss more than Ni. Therefore biochar may not be good for maintaining soil fertility over a long period. Instead, applying Ni may be an optimal practice to ensure food security, while decreasing gaseous N loss, for rice production in the Taihu Lake region of China.
生物炭和硝化抑制剂作为提高氮素利用效率（NUE）的改良剂越来越受到重视。然而，它们对稻田土壤反硝化作用和主要氮损失的影响在整个水稻生长季节还没有得到很好的理解。本研究采用原状土芯培养结合 N/Ar 技术，在中国太湖地区进行了两个水稻生长季的田间试验，研究了生物炭和硝化抑制剂（2-氯-6-（三氯甲基）-吡啶）对水稻产量和土壤反硝化作用以及氨（NH）挥发的影响。试验共设置 4 个处理：不施氮（N0）、施氮 270kg/ha（N270）、施氮 270kg/ha 并添加 25t/ha 生物炭（N270+C）和施氮 270kg/ha 并添加 1.35kg/ha 2-氯-6-（三氯甲基）-吡啶（N270+Ni）。与单独施氮（N270）相比，生物炭（N270+C）和硝化抑制剂（N270+Ni）的施用分别提高了水稻产量 4.2-5.2%和 6.2-7.3%。不同处理的累积 N-N 和 NH-N 损失分别为施氮量的 11.9-21.8%和 11.5-22.0%。与单独施氮相比，硝化抑制剂的施用使总 NH 排放增加了 4.0-20.6%，总 N-N 排放显著减少了 9.7-19.4%（p<0.05），而生物炭的施用使总 NH 和 N-N 排放分别增加了 8.6-17.9%和 3.3-9.7%。总的来说，生物炭的施用比硝化抑制剂的施用产生了 11-15%更高的净气态 N。虽然生物炭的施用可能会提高水稻产量，进而增加植物对氮的吸收，但它也会促进氮素的损失，比硝化抑制剂的作用更明显。因此，生物炭的施用可能不利于长期保持土壤肥力。相反，在中国太湖地区，施用硝化抑制剂可能是一种确保粮食安全、减少气态 N 损失的最佳实践。
