Biochar Addition with Water and Fertilization Reduction Increases Soil Aggregate Stability of 0–60 cm Soil Layer on Greenhouse Eggplant in Mollisols

Abstract

Biochar application affects the soil organic carbon (SOC) content and distribution, which is relevant to facility agriculture and soil aggregates. However, how the fertilization management of facility agriculture affects the SOC content and aggregate stability at different soil depths in Mollisols is unclear. Intended to provide a basis for developing a reasonable fertilizer amount when adding biochar, the facility vegetable eggplant in Northeast China was used to explore the effects of biochar addition on the distribution and SOC content of whole soils and the organic carbon (OC) content of aggregates of each size in the profile (0–100 cm) of Mollisols. Three treatments were set up: WF (conventional application amounts of water and fertilizer), WFB (conventional application amounts of water and fertilizer and added biochar), and 80%W80%FB (20% water reduction and 20% fertilizer reduction and added biochar). The results demonstrated that the 80%W80%FB treatment significantly increased the SOC content by 56.1% and 34.0% in whole soils at a 0–20 cm soil depth compared to WF and WFB treatments, respectively. Simultaneously, compared with WF and WFB treatments, the significant increase in the OC content of 1–0.25 mm sized aggregates of 81.4–130.2% and 4.3–10.1% and the enhanced proportion of >2 mm sized aggregates of 0.22–16.15- and 0.33–0.83-fold both improved aggregate stability in the 0–20 cm soil layer under the 80%W80%FB treatment, which was proven to result in 32.6% and 30.6% increments in the weight diameter (MWD) value. Therefore, biochar addition with water and fertilizer reductions increases surface soil aggregate stability for greenhouse eggplants in Mollisols.

Biochar for Sustainable Farming and Recultivation

“…The Special Issue consists of four subjects centered around "Biochar for Sustainable Farming and Recultivation". These subjects are: (1) the research progress of biochar in carbon sequestration and emission reduction [5]; (2) the consequences of biochar application on soil aggregation [6,7]; (3) the influence of biochar addition on the humification process of organic wastes [8]; and (4) the effects of biochar addition on soil organic carbon transformation and composition [9]. This Special Issue covers both theoretical mechanisms and practical applications, including laboratory incubations and field experiments.…”

“…In the context of facility agriculture, Xu et al [6] examined the impact of biochar addition on the content of soil organic carbon (SOC) and the stability of aggregates in Mollisols cultivated with eggplants in a greenhouse environment. The study revealed that the incorporation of biochar and reduced water-fertilizer inputs has a significant effect on SOC content and the stability of aggregates.…”

‘Soil and Plant Nutrition’—A Section of Agronomy: Advances and Perspectives

“…Biochar is the most intensively investigated amendment and is widely described in the literature, including in the 'Soil and Plant Nutrition' section [6,[21][22][23][33][34][35][36][37][38][39]. Many review papers (1327 reviews indexed in the Web of Science Core Collection in categories related to agronomy) and meta-analyses have already been written on this subject [40][41][42][43][44][45][46][47][48].…”