Data_Sheet_1_Biochar and Intercropping With Potato–Onion Enhanced the Growth and Yield Advantages of Tomato by Regulating the Soil Properties, Nutrient Uptake, and Soil Microbial Community.docx

The application of biochar stimulates the activities of microorganisms that affect soil quality and plant growth. However, studies on the impacts of biochar mainly focus on a monoculture, its effects on interspecific interactions are rarely reported. Here, we investigated the impacts of biochar on tomato/potato–onion intercropped (TO) in a pot experiment. Tomato monoculture (T) and TO were treated with no, 0.3, 0.6, and 1.2% biochar concentrations in a pot experiment. Microbial communities from tomato rhizosphere soil were analyzed by quantitative PCR and Illumina MiSeq. The results showed that compared with the tomato monoculture, 0.6%TO and 1.2%TO significantly increased tomato yield in 2018. TO and 1.2%TO significantly increased plant height and dry weight in 2018 and 2019. Biochar treatments increased soil pH, decreased NO3--N and bulk density, and increased the absorption of N, P, and K by tomato. Bacterial and fungal abundances increased with an increase in biochar concentration, while Bacillus spp. and Pseudomonas spp. abundances showed an “increase-decrease-increase” trend. Biochar had a little effect on bacterial diversities but significantly lowered fungal diversities. TO, 0.6%TO, and 1.2%TO increased the potentially beneficial organisms (e.g., Pseudeurotium and Solirubrobacter) and lowered the potentially pathogenic organisms (e.g., Kribbella and Ilyonectria). Different concentrations of biochar affected the bacterial and fungal community structures. Redundancy analysis indicated that the bacterial community was strongly correlated with soil pH, NO3--N, and EC, while the fungal community was closely related to soil NO3--N and moisture. The network analysis showed that biochar and intercropping affected the symbiosis pattern of the microorganisms and increased the proportion of positive interactions and nitrifying microorganisms (Nitrospirae) in the microbial community. Overall, our results indicated that monoculture and intercropping with biochar improved soil physicochemical states and plant nutrient absorption, and regulated soil microbial communities, these were the main factors to promote tomato growth and increase tomato productivity.

生物炭（biochar）的施用可激活影响土壤质量与植物生长的微生物活性。然而，现有关于生物炭影响效应的研究多聚焦于单作体系，其对物种间相互作用的影响却鲜有报道。
本研究通过盆栽试验，探究了生物炭对番茄/马铃薯-洋葱间作体系（tomato/potato–onion intercropped，简称TO）的影响。试验设置单作番茄（T）以及TO两种种植模式，并分别施加0%、0.3%、0.6%、1.2%四个浓度梯度的生物炭处理。
采用定量聚合酶链反应（quantitative PCR，qPCR）与Illumina MiSeq测序平台（Illumina MiSeq），对番茄根际土壤的微生物群落进行了分析。
研究结果显示：相较于单作番茄组，2018年0.6%TO与1.2%TO处理组的番茄产量显著提升；2018及2019年，TO与1.2%TO处理组的番茄株高与干重均显著增加。
生物炭处理可提升土壤pH值，降低土壤硝态氮（NO₃⁻-N）含量与容重，并促进番茄对氮、磷、钾的吸收。
细菌与真菌的丰度随生物炭浓度升高而上升，而芽孢杆菌属（Bacillus spp.）与假单胞菌属（Pseudomonas spp.）的丰度则呈现“升-降-升”的变化趋势。
生物炭对细菌多样性的影响较弱，但可显著降低真菌多样性。
TO、0.6%TO与1.2%TO处理组可提升潜在有益微生物（如假裸囊菌属Pseudeurotium、土杆菌属Solirubrobacter）的相对丰度，并降低潜在致病微生物（如克氏杆菌属Kribbella、伊利亚霉属Ilyonectria）的占比。
不同浓度的生物炭均会改变细菌与真菌的群落结构。冗余分析（Redundancy analysis，RDA）结果表明，细菌群落与土壤pH值、硝态氮含量及电导率（EC）显著相关；而真菌群落则与土壤硝态氮含量及土壤含水量密切相关。
网络分析显示，生物炭施用与间作模式改变了微生物的共生模式，并提升了微生物群落中正相互作用的占比以及硝化螺旋菌门（Nitrospirae）等硝化微生物的比例。
综合来看，本研究结果表明，单作与间作体系施加生物炭均可改善土壤理化性状、促进植物对养分的吸收，并调控土壤微生物群落结构，这也是推动番茄生长、提升番茄产量的核心因素。