Biochar application has been recognised as an effective way to improve soil functions. In this study, we investigated how adding biochar as an amendment affects soil biological and physico-chemical properties in grazed pastures in a one-year field-based mesocosm experiment conducted on two contrasting soils – a sil-andic Andosol and a dystric Cambisol. Each site had two pastures managed under different nutrient and livestock practices: with and without effluent under dairy cow grazing on the Andosol, and with either nil or high phosphorus (P) fertiliser input under sheep grazing on the Cambisol. The soil amendment treatments were: (i) willow biochar produced at 350 °C (1% w/w); (ii) lime, added at the liming equivalence of the biochar application (positive control); (iii) no amendments (negative control). With few exceptions, after 12 months and compared with initial values and controls, biochar caused (i) an increase in soil total nitrogen (N) and Olsen P content (all P < 0.005) beyond those expected from the N and P added with biochar; (ii) decrease in soil bulk density (P < 0.005), on average by 7%, more than can be explained by the reduced density of the biochar added; (iii) increase in microbial biomass C (P < 0.005), and (iv) increase in root biomass by 6.9 Mg ha⁻¹ (P < 0.005). Lime addition increased pH values in both soils under all four management practices, and increased earthworm abundance compared with controls across all sites. In biochar-amended soils, earthworm abundance was higher only in the Andosol without effluent (P < 0.05), while Collembola abundance was significantly higher (P < 0.005) than the controls in all pastures; there was no effect on soil Oribatida and Gamasina populations. Adding biochar made from willow wood produced at low temperature to these pasture soils can positively affect the soil structure, nutrient cycling, and stimulate root growth, a key contributor to organic C input to the soil and the soil food web.

生物炭的应用已被公认为改善土壤功能的有效途径。在这项研究中，我们在为期一年的田间中观实验中研究了添加 biochar 作为改良剂如何影响放牧牧场的土壤生物和物理化学特性，该实验是在两种对比土壤上进行的，为期一年的田间中观实验 - 一种硅土质 Andosol 和一种营养失调的 Cambisol。每个地点都有两个牧场，在不同的营养和牲畜做法下进行管理：在 Andosol 放牧的奶牛下有和没有污水，以及在 Cambisol 放牧的绵羊下施用零或高磷 (P) 肥料。土壤改良处理是：（i）在 350 °C 下生产的柳树生物炭（1% w/w）；(ii) 石灰，在生物炭应用的石灰等效添加（阳性对照）；(iii) 无修正（阴性对照）。除了少数例外，P  < 0.005) 超出了 N 和 P 添加生物炭的预期；(ii) 土壤容重降低 ( P  < 0.005)，平均降低 7%，超过添加生物炭密度降低的原因；(iii) 微生物生物量 C 增加 ( P  < 0.005)，和 (iv) 根生物量增加 6.9 Mg ha ^-1 ( P  < 0.005)。在所有四种管理实践下，石灰添加增加了两种土壤的 pH 值，与所有地点的对照相比，增加了蚯蚓的丰度。在生物炭改良土壤中，蚯蚓丰度仅在没有出水的 Andosol 中较高（P  < 0.05），而跳虫丰度显着较高（P < 0.005) 比所有牧场的对照；对土壤 Oribatida 和 Gamasina 种群没有影响。将低温生产的柳木制成的生物炭添加到这些牧场土壤中，可以对土壤结构、养分循环和刺激根系生长产生积极影响，根系生长是有机碳输入土壤和土壤食物网的关键因素。