Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, 210037, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou, China.
Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou, China.
Chemosphere. 2019 Dec;237:124532. doi: 10.1016/j.chemosphere.2019.124532. Epub 2019 Aug 8.
Biochar (BC) potentially accelerates ammonia (NH) volatilization from rice paddy soils. In this regard, however, application the floating duckweed (FDW) to biochar-amended soil to control the NH volatilization is not studied up-to-date. Therefore, the impacts of BC application with and without FDW on the NH and nitrous oxide (NO) emissions, NUE and rice grain yield were evaluated in a soil columns experiment. We repacked soil columns with Hydragric Anthrosol and Haplic Acrisol treated in triplicates with Urea, Urea + BC and Urea + BC + FDW. Total NH losses from Hydragric Anthrosol and Haplic Acrisol were 15.2-33.2 kg N ha and 19.6-39.7 kg N ha, respectively. Urea + BC treatment recorded 25.6-43.7% higher (p < 0.05) NH losses than Urea treatment, attributing to higher pH value of floodwater. Floating duckweed decreased soil pH and therefore significantly reduced (p < 0.05) the NH volatilizations from the two soils by 50.6-54.2% over Urea + BC and by 34.2-38.0% over Urea treatment. Total NO emissions from Hydragric Anthrosol and Haplic Acrisol were 1.19-3.42 kg N ha and 0.67-2.08 kg N ha, respectively. Urea + BC treatment increased NO emissions by 58.8-68.7% and Urea + BC + FDW treatment further increased NO emission by 187.4-210.4% over Urea treatment. Higher ammonium content of the topsoil, explained the NO increases in the Urea + BC and Urea + BC + FDW treatments. Urea + BC slightly reduced the rice grain yield and NUE, while the Urea + BC + FDW promoted both rice yield and NUE. Our data indicate that co-application of FDW along with BC in paddy soil could mitigate the NH volatilization and enhance the rice grain yield and NUE.
生物炭（BC）可能会加速水稻田中的氨（NH）挥发。然而，在这方面，目前尚未研究将浮萍（FDW）应用于添加生物炭的土壤中以控制 NH 挥发。因此，在土壤柱实验中评估了 BC 与 FD W 的应用对 NH 和氧化亚氮（NO）排放、氮素利用率（NUE）和水稻籽粒产量的影响。我们用 Hydragric Anthrosol 和 Haplic Acrisol 重新填充土壤柱，并分别用 Urea、Urea+BC 和 Urea+BC+FDW 处理重复三次。Hydragric Anthrosol 和 Haplic Acrisol 的总 NH 损失分别为 15.2-33.2kgNha 和 19.6-39.7kgNha。与 Urea 处理相比，Urea+BC 处理记录的 NH 损失高 25.6-43.7%（p<0.05），这归因于洪水的 pH 值更高。浮萍降低了土壤 pH 值，因此与 Urea+BC 相比，NH 挥发降低了 50.6-54.2%，与 Urea 处理相比，NH 挥发降低了 34.2-38.0%。Hydragric Anthrosol 和 Haplic Acrisol 的总 NO 排放分别为 1.19-3.42kgNha 和 0.67-2.08kgNha。与 Urea 处理相比，Urea+BC 处理增加了 58.8-68.7%的 NO 排放，而 Urea+BC+FDW 处理进一步增加了 187.4-210.4%的 NO 排放。表层土壤中铵态氮含量较高，解释了 Urea+BC 和 Urea+BC+FDW 处理中 NO 增加的原因。Urea+BC 处理略微降低了水稻籽粒产量和 NUE，而 Urea+BC+FDW 处理则促进了水稻产量和 NUE。我们的数据表明，在稻田土壤中同时应用 FD W 和 BC 可以减轻 NH 挥发，并提高水稻籽粒产量和 NUE。
