农业土壤中的镉(Cd)污染是全球关注的土壤健康和食物可持续性,因为它会导致谷物中的Cd积累。原位稳定技术(使用有机改良剂)已广泛用于耕地中的Cd修复。因此,本研究考察了蚯蚓粪(VC)对土壤生化性状的影响,细菌群落多样性和组成,2022年生长季节后期,Cd污染土壤中水稻植株对Cd的吸收和积累以及籽粒产量。不同剂量的VC(即,V1=0tha-1,V2=3tha-1和V3=6tha-1)和两种浓度的Cd(即,使用Cd1=0和Cd2=50mgCdKg-1。我们对16S核糖体RNA基因扩增子进行了高通量测序,以表征土壤细菌群落。VC的添加极大地影响了土壤细菌群落的多样性和组成;并增加了氯氟虫的相对丰度,变形杆菌,酸杆菌,植物群落,Gemmatimonadota,杆菌和Firmicute。此外,VC应用程序,特别是高VC治疗,表现出最高的细菌多样性和丰富度(即,辛普森,香农,ACE,和Chao1指数)。同样,VC的施用增加了土壤化学性状,包括土壤pH值,土壤有机碳(SOC),可用氮气(AN),总氮(TN),总钾(TK),总磷(TP)和酶活性(即,酸性磷酸酶,过氧化氢酶,脲酶和转化酶)与Cd胁迫下非VC处理的土壤相比。SOC的平均增加,TN,AN,TK和TP为5.75%,41.15%,18.51%,12.31%,25.45%和29.67%,分别,与Cd胁迫土壤相比,高VC处理(Pos-CdVC3)。冗余分析表明,主要的细菌门与SOC相关,AN,TN,TP和pH,尽管Firmicutes的相对丰富,变形杆菌,细菌,基于门的酸细菌和放线菌,γ变形杆菌和粘液球菌,与土壤环境因子高度相关。此外,VC的施用抵消了Cd对植物的不利影响,并显着降低了Cd在水稻器官中的吸收和积累,比如根,Cd胁迫条件下的茎+叶和籽粒。同样,施用VC显著提高了Cd毒害下香稻的产量和产量性状。相关分析表明,增加的土壤数量性状对获得水稻高产至关重要。一般来说,这项研究的结果表明,VC在稻田中的应用可以通过可持续地提高土壤功能和作物产量来对中国南方的种植者有用。
Cadmium (Cd) contamination in agricultural soil is a global concern for soil health and food sustainability because it can cause Cd accumulation in cereal grains. An in-situ stabilizing technology (using organic amendments) has been widely used for Cd remediation in arable lands. Therefore, the current study examined the influence of vermicompost (VC) on soil biochemical traits, bacterial community diversity and composition, Cd uptake and accumulation in rice plants and grain yield in a Cd-contaminated soil during the late growing season in 2022. Different doses of VC (i.e., V1 = 0 t ha-1, V2 = 3 t ha-1 and V3 = 6 t ha-1) and two concentrations of Cd (i.e., Cd1 = 0 and Cd2 = 50 mg Cd Kg-1 were used. We performed high-throughput sequencing of 16S ribosomal RNA gene amplicons to characterize soil bacterial communities. The addition of VC considerably affected the diversity and composition of the soil bacterial community; and increased the relative abundance of phyla Chloroflexi, Proteobacteria, Acidobacteriota, Plantomycetota, Gemmatimonadota, Patescibacteria and Firmicute. In addition, VC application, particularly High VC treatment, exhibited the highest bacterial diversity and richness (i.e., Simpson, Shannon, ACE, and Chao 1 indexes) of all treatments. Similarly, the VC application increased the soil chemical traits, including soil pH, soil organic carbon (SOC), available nitrogen (AN), total nitrogen (TN), total potassium (TK), total phosphorous (TP) and enzyme activities (i.e., acid phosphatase, catalase, urease and invertase) compared to non-VC treated soil under Cd stress. The average increase in SOC, TN, AN, TK and TP were 5.75%, 41.15%, 18.51%, 12.31%, 25.45% and 29.67%, respectively, in the High VC treatment (Pos-Cd + VC3) compared with Cd stressed soil. Redundancy analysis revealed that the leading bacterial phyla were associated with SOC, AN, TN, TP and pH, although the relative abundance of Firmicutes, Proteobacteria, Bacteroidata, and Acidobacteria on a phylum basis and Actinobacteria, Gammaproteobacteria and Myxococcia on a class basis, were highly correlated with soil environmental factors. Moreover, the VC application counteracted the adverse effects of Cd on plants and significantly reduced the Cd uptake and accumulation in rice organs, such as roots, stem + leaves and grain under Cd stress conditions. Similarly, applying VC significantly increased the fragrant rice grain yield and yield traits under Cd toxicity. The correlation analysis showed that the increased soil quantities traits were crucial in obtaining high rice grain yield. Generally, the findings of this research demonstrate that the application of VC in paddy fields could be useful for growers in Southern
China by sustainably enhancing soil functionality and crop production.