Sun Haijun, Chen Ying, Yi Zhenghua
Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China.
Plants (Basel). 2022 Dec 9;11(24):3444. doi: 10.3390/plants11243444.
Biochar use in agriculture brings significant agronomic and environmental co-benefits, which are a function of biochar and crop types and nitrogen (N) rates. We here conducted a soil column experiment to evaluate the after-effects of hydrochar amendment at 0.5 and 2.0 wt% on vegetable production, N recovery and losses via leaching and nitrous oxide (N2O) emission from water-spinach (Ipomoea aquatica Forsk)-planted vegetable soil receiving three N inputs (120, 160, and 200 kg/ha). The results showed that hydrochar with 2.0 wt% significantly (p < 0.05) improved the biomass yield of water spinach, receiving 120−160 kg N/ha by 11.6−14.2%, compared with no change in the hydrochar treatment. Hydrochar had no effect on total N content of water spinach, and only increased the total N recovery under 2.0 wt% given hydrochar amended treatment with 120 kg N/ha. Neither pH or EC of leachate was changed with N reduction or hydrochar application. However, in some cases, hydrochar changes the NH4+, NO3− and total N concentrations in leachate. When applied at 2.0 wt%, hydrochar significantly (p < 0.05) increased total N leaching losses by 28.9% and 57.1%, under 120 and 160 kg N/ha plot, respectively. Hydrochar applied at two rates increased the N2O emissions by 109−133% under 200 kg N/ha but decreased them by 46−67% under 160 kg N/ha. Therefore, after three years of application, hydrochar still improves the production of leafy vegetable, but the impacts on N leaching and N2O emission vary, depending on inorganic N and hydrochar application rates.
在农业中使用生物炭可带来显著的农学和环境协同效益，这些效益取决于生物炭、作物类型和氮（N）施用量。我们在此进行了一项土柱实验，以评估在接受三种氮输入量（120、160和200千克/公顷）的水蕹菜（蕹菜）种植蔬菜土壤中，添加0.5%和2.0%（重量）的水炭对蔬菜产量、氮素回收以及通过淋溶和一氧化二氮（N₂O）排放造成的氮损失的后续影响。结果表明，添加2.0%（重量）水炭显著（p < 0.05）提高了水蕹菜的生物量产量，与未添加水炭处理无变化相比，在施氮量为120 - 160千克/公顷时提高了11.6% - 14.2%。水炭对水蕹菜的总氮含量没有影响，仅在添加2.0%（重量）水炭且施氮量为120千克/公顷的处理下提高了总氮回收率。随着氮素减少或水炭施用，淋溶液的pH值和电导率均未改变。然而，在某些情况下，水炭会改变淋溶液中的铵离子、硝酸根离子和总氮浓度。当添加量为2.0%（重量）时，在施氮量为120千克/公顷和160千克/公顷的小区中，水炭分别显著（p < 0.05）增加了总氮淋溶损失28.9%和57.1%。在施氮量为200千克/公顷时，两种添加量的水炭使N₂O排放量增加了109% - 133%，但在施氮量为160千克/公顷时减少了46% - 67%。因此，施用三年后，水炭仍能提高叶菜类蔬菜的产量，但对氮淋溶和N₂O排放的影响因无机氮和水炭施用量而异。
