Department of Physical Geography, Stockholm University, Stockholm, Sweden; Bolin Centre for Climate Research, Stockholm, Sweden.
Department of Physical Geography, Stockholm University, Stockholm, Sweden; Bolin Centre for Climate Research, Stockholm, Sweden.
Sci Total Environ. 2019 Mar 20;657:853-862. doi: 10.1016/j.scitotenv.2018.11.312. Epub 2018 Nov 22.
There is an urgent need to develop agricultural methods that balance water supply and demand while at the same time improve resilience to climate variability. A promising instrument to address this need is biochar - a charcoal made from pyrolyzed organic material. However, it is often unclear how, if at all, biochar improves soil water availability, plant water consumption rates and crop yields. To address this question, we synthesized literature-derived observational data and evaluated the effects of biochar on evapotranspiration using a minimal soil water balance model. Results from the model were interpreted in the Budyko framework to assess how climatic conditions mediate the impacts of biochar on water fluxes. Our analysis of literature-derived observational data showed that while biochar addition generally increases the soil water holding capacity, it can have variable impacts on soil water retention relative to control conditions. Our modelling demonstrated that biochar increases long-term evapotranspiration rates, and therefore plant water availability, by increasing soil water retention capacity - especially in water-limited regions. Biochar amendments generally increased crop yields (75% of the compiled studies) and, in several cases (35% of the compiled studies), biochar amendments simultaneously increased crop yield and water use efficiencies. Hence, while biochar amendments are promising, the potential for variable impact highlights the need for targeted research on how biochar affects the soil-plant-water cycle.
目前迫切需要开发一种农业方法，在平衡水资源供需的同时，提高对气候变异性的适应能力。生物炭是一种有前途的工具，可以满足这一需求——它是由热解有机材料制成的木炭。然而，生物炭如何提高土壤水分可用性、植物耗水率和作物产量，这一点往往并不清楚。为了解决这个问题，我们综合了文献中得出的观测数据，并使用最小土壤水分平衡模型来评估生物炭对蒸散的影响。我们根据模型的结果在 Budyko 框架内进行了解释，以评估气候条件如何调节生物炭对水通量的影响。我们对文献中得出的观测数据的分析表明，虽然生物炭的添加通常会增加土壤的持水能力，但它对土壤水分保持相对于对照条件的影响是可变的。我们的模型表明，生物炭通过增加土壤水分保持能力，从而增加长期蒸散速率，进而增加植物水分可用性——特别是在水资源有限的地区。生物炭改良剂通常会增加作物产量（在汇编的研究中占 75%），并且在某些情况下（在汇编的研究中占 35%），生物炭改良剂同时提高了作物产量和水分利用效率。因此，虽然生物炭改良剂很有前景，但由于其影响具有变异性，因此需要针对生物炭如何影响土壤-植物-水循环进行有针对性的研究。
