Petter Fabiano André, de Lima Larissa Borges, Marimon Júnior Ben Hur, Alves de Morais Leidimar, Marimon Beatriz Schwantes
Universidade Federal de Mato Grosso (UFMT), Instituto de Ciências Agrárias e Ambientais, CEP: 78557-267, Sinop, MT, Brazil.
Universidade Federal de Mato Grosso (UFMT), Instituto de Ciências Agrárias e Ambientais, CEP: 78557-267, Sinop, MT, Brazil.
J Environ Manage. 2016 Mar 15;169:27-33. doi: 10.1016/j.jenvman.2015.12.020. Epub 2015 Dec 22.
The objective of this research was to assess the emission of nitrous oxide (N2O) from soil amended with biochar in the culture of upland rice. The experiment was conducted in the field in a Cerrado Haplic Plinthosol under randomized block experimental design. The treatments consisted of fertilization with 100 kg N ha(-1) split into two applications, 60% at sowing and 40% at 45 days after crop emergence, combined with four doses of biochar (0, 8, 16 and 32 Mg ha(-1)), with four replications. The application of N and the emission of N2O, moisture retention and soil temperature, respiration (C-CO2), microbial biomass carbon in the soil (C-SMB), total nitrogen (TN), pH and agronomic efficiency in N use (AENu) were evaluated five years after the application of biochar. There was a significant correlation of the application of biochar with moisture retention (r = 0.94**), N2O emission (r = 0.86**) and soil pH (r = 0.65*), and N2O emissions showed a positive correlation (p < 0.05) with soil moisture (r = 0.77**) and pH (r = 0.66*). Thus the highest N2O emissions were observed shortly after N fertilization and in the treatments with 32 Mg ha(-1) of biochar. Despite the higher N2O emissions from the application of 32 Mg ha(-1) of biochar, the emission factor was lower (0.81%) than the maximum recommended by the IPCC. The higher N2O emissions with application of biochar are offset by more efficient use of N and consequently the possibility of reduction of applied doses.
本研究的目的是评估在旱稻种植中添加生物炭的土壤中一氧化二氮（N₂O）的排放情况。试验在塞拉多强发育湿润老成土的田间进行，采用随机区组试验设计。处理包括施用100 kg N ha⁻¹，分两次施用，播种时施60%，作物出苗后45天施40%，并结合四种生物炭剂量（0、8、16和32 Mg ha⁻¹），重复四次。在施用生物炭五年后，评估了氮的施用以及N₂O排放、水分保持、土壤温度、呼吸作用（C-CO₂）、土壤微生物生物量碳（C-SMB）、总氮（TN）、pH值和氮利用农学效率（AENu）。生物炭的施用与水分保持（r = 0.94**）、N₂O排放（r = 0.86**）和土壤pH值（r = 0.65*）存在显著相关性，并且N₂O排放与土壤湿度（r = 0.77**）和pH值（r = 0.66*）呈正相关（p < 0.05）。因此，在施氮后不久以及施用32 Mg ha⁻¹生物炭的处理中观察到最高的N₂O排放。尽管施用32 Mg ha⁻¹生物炭时N₂O排放量较高，但其排放因子（0.81%）低于IPCC推荐的最大值。生物炭施用导致的较高N₂O排放被更高效的氮利用所抵消，因此有可能减少施用量。
