Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, 410125, China.
Faculty of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China.
Environ Sci Pollut Res Int. 2018 Mar;25(7):6407-6413. doi: 10.1007/s11356-017-0989-8. Epub 2017 Dec 16.
In the hilly areas of southern China, uplands and paddies are located adjacent to each other. Using rice straw as mulch for upland soil may improve crop production and partially replace chemical fertilizers, which may mitigate NO emissions. A field experiment was conducted to investigate the potential of rice straw mulching for mitigating NO emissions and increasing crop production. The treatments included no mulching (CK), 5000 kg ha of straw mulching (SM5), and 10,000 kg ha of straw mulching (SM10). Moreover, all the treatments received equivalent amounts of nitrogen, phosphorus, and potassium from chemical fertilizers plus rice straw. Relative to CK, cumulative NO emissions decreased by 23.1 and 33.5% with SM5 and SM10, respectively. Significant positive correlations were observed between NO fluxes and soil water-filled pore space (WPFS) (r = 0.495, P < 0.05) and between seasonal cumulative NO fluxes and the chemical N fertilization rate (r = 0.814, P < 0.05). These findings indicate that soil WPFS was the key environmental factor in NO emissions and that the substitution of chemical nitrogen fertilizer with rice straw was the main driver of NO mitigation. Relative to CK, the maize yield increased by 16.5 and 29.6% with SM5 and SM10, respectively, which can be attributed primarily to the increases in soil moisture. The chemical fertilizer input could be decreased and NO emissions could be mitigated through straw mulching, while achieving improved crop yield. This management strategy has great potential, and this study provides an important reference for low-carbon agriculture.
在中国南方的丘陵地区，旱地和稻田相邻。在旱地土壤上使用稻秆作为覆盖物可以提高作物产量，并部分替代化肥，从而减少氮氧化物排放。本田间试验旨在研究稻秆覆盖对减少氮氧化物排放和提高作物产量的潜力。处理措施包括不覆盖（对照）、覆盖 5000 公斤/公顷稻秆（SM5）和覆盖 10000 公斤/公顷稻秆（SM10）。此外，所有处理均通过化肥和稻秆获得等量的氮、磷和钾。与对照相比，SM5 和 SM10 分别使累积氮氧化物排放量减少了 23.1%和 33.5%。氮氧化物通量与土壤水填满孔隙空间（WPFS）之间呈显著正相关（r=0.495，P<0.05），季节性累积氮氧化物通量与化学氮肥施用量之间呈极显著正相关（r=0.814，P<0.05）。这些结果表明，土壤 WPFS 是氮氧化物排放的关键环境因素，而用稻秆替代化学氮肥是减少氮氧化物排放的主要驱动因素。与对照相比，SM5 和 SM10 分别使玉米产量增加了 16.5%和 29.6%，这主要归因于土壤水分的增加。通过稻秆覆盖可以减少化肥投入和氮氧化物排放，同时提高作物产量。这种管理策略具有很大的潜力，本研究为低碳农业提供了重要参考。
