Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Sci Total Environ. 2019 Oct 1;685:741-752. doi: 10.1016/j.scitotenv.2019.06.244. Epub 2019 Jun 17.
The combined use of biochar and compost as a soil amendment presents benefits to crops and nutrient cycling. Although there are literature reviews regarding biochar and biochar-compost mixtures, a quantitative literature review on the role of co-composted biochar (hereby called COMBI) in plant productivity is currently missing. The goal of this review paper is to find evidence-based measures of the effects of application rates, soil pH, plant types, biochar feedstock, and compost materials, on plant productivity. Plant productivity covers a variety of measurements but mostly refers to grain yield and above-ground biomass. Response ratio was selected as the effect size. Funnel plot showed that the studies were reasonably symmetrically distributed around the mean effect size. Results showed that application rates of <20 t/ha and >30 t/ha significantly increased plant productivity by 48.3 and 15.7%, respectively, while no significant yield increases were found for the application rates between 20 and 30 t/ha. When data was grouped based on the soil pH, the greatest increase in plant productivity was found to be at acidic soil pH values (pH 4-5), which was expected because the liming effect of biochar is often reported as one of the main mechanisms behind the increased crop yields. When different plant species were compared, cereal grasses grown with COMBI yielded significantly higher grain yields (39.7%). Rice husk biochar yielded the highest increase in productivity but this result was based on only one study. The second highest increase was obtained with wood-based biochars (29.4%) based on ten studies. The effect sizes found with our meta-analyses are based on 14 research works worldwide and represent the most updated information regarding the effects of COMBI on plant production. As more data on COMBI become available, data analyses can be updated to make more robust comparisons.
生物炭和堆肥的联合使用作为土壤改良剂对作物和养分循环都有好处。虽然有关于生物炭和生物炭-堆肥混合物的文献综述，但目前缺乏关于共堆肥生物炭（简称 COMBI）在植物生产力中的作用的定量文献综述。本文的目的是寻找应用率、土壤 pH 值、植物类型、生物炭原料和堆肥材料对植物生产力影响的基于证据的措施。植物生产力涵盖了多种测量方法，但主要是指粮食产量和地上生物量。响应比被选为效应量。漏斗图表明，研究结果在平均效应量周围以合理的对称方式分布。结果表明，应用率<20 t/ha 和>30 t/ha 分别显著提高了 48.3%和 15.7%的植物生产力，而在 20 和 30 t/ha 之间的应用率下没有发现显著的产量增加。当根据土壤 pH 值对数据进行分组时，发现植物生产力的最大增加发生在酸性土壤 pH 值（pH 4-5），这是意料之中的，因为生物炭的石灰化作用通常被认为是提高作物产量的主要机制之一。当比较不同的植物物种时，与 COMBI 一起生长的谷类草产生的谷物产量显著更高（39.7%）。稻壳生物炭产生的生产力增加最高，但这一结果仅基于一项研究。基于十项研究，基于木质素的生物炭获得了第二高的增长（29.4%）。我们的荟萃分析发现的效应量基于全球 14 项研究工作，代表了关于 COMBI 对植物生产影响的最新信息。随着更多关于 COMBI 的数据可用，数据分析可以更新，以进行更稳健的比较。
