Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410221, China.
Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
Sci Total Environ. 2024 Mar 1;914:169900. doi: 10.1016/j.scitotenv.2024.169900. Epub 2024 Jan 9.
Intercropping is a widely used agricultural system; however, the effect of intercropping between accumulator plants on phytoextraction in heavy metal-contaminated soils remains unknown. Here, a field experiment was conducted to investigate the phytoextraction efficiency and related environmental effects of three Amaranthaceae plants (Amaranthus hypochondriacus, Celosia argentea, and Pfaffia glomerata) using mono- and intercropping models. In monocropping, the total biomass of A. hypochondriacus was only 51.2 % of that of C. argentea. Compared with monocropping, intercropping reduced the fresh weight per plant of A. hypochondriacus by 53.0 % (intercropping with C. argentea) and 40.5 % (intercropping with P. glomerata) but increased the biomass per plant of C. argentea and P. glomerata by 128.2 and 14.2 %, respectively. The Cd uptake of the three plants in the monocropping models showed the following trend: C. argentea > P. glomerata > A. hypochondriacus. Interplanting A. hypochondriacus and C. argentea further increased the phytoextraction efficiency by 361.2 % (compared with A. hypochondriacus monocropping) and 52.0 % (compared with C. argentea monocropping). Soil exchangeable Cd, Pb, Cu, Zn, K, and P, soil N-NO and N-NH, soil common bacteria and arbuscular mycorrhiza (AM) fungi, and soil total organic carbon (TOC) play key roles in Cd and Pb uptake by the three accumulator plants (p < 0.05). The biomass of common bacteria, Gm, Gm bacteria, fungi, AM fungi, and actinomycetes increased with the three accumulators planted in the mono- and intercropping models. Compared with C. argentea monocropping, the biomass of soil microbes in the rhizosphere soil was obviously increased in the intercropping A. hypochondriacus and C. argentea models. These results suggest that interplanting A. hypochondriacus and C. argentea can increase Cd removal efficiency from Cd-contaminated soils, and this model could be recommended to remediate Cd-contaminated soils on a field scale.
间作是一种广泛应用的农业系统；然而，在重金属污染土壤中，积累植物间作对植物提取的影响尚不清楚。在这里，进行了田间试验，以研究三种苋科植物（反枝苋、青葙和垂穗商陆）在单作和间作模式下的植物提取效率及相关环境效应。在单作中，反枝苋的总生物量仅为青葙的 51.2%。与单作相比，间作使反枝苋的单株鲜重减少了 53.0%（与青葙间作）和 40.5%（与垂穗商陆间作），而青葙和垂穗商陆的单株生物量分别增加了 128.2%和 14.2%。三种植物在单作模式下的 Cd 吸收表现出以下趋势：青葙>垂穗商陆>反枝苋。间作反枝苋和青葙进一步将植物提取效率提高了 361.2%（与反枝苋单作相比）和 52.0%（与青葙单作相比）。土壤可交换态 Cd、Pb、Cu、Zn、K 和 P、土壤 N-NO 和 N-NH、土壤常见细菌和丛枝菌根（AM）真菌以及土壤总有机碳（TOC）在三种积累植物对 Cd 和 Pb 的吸收中起关键作用（p<0.05）。常见细菌、Gm、Gm 细菌、真菌、AM 真菌和放线菌的生物量随着三种积累植物在单作和间作模式下的种植而增加。与青葙单作相比，间作反枝苋和青葙模式下根际土壤中土壤微生物的生物量明显增加。这些结果表明，间作反枝苋和青葙可以提高从 Cd 污染土壤中去除 Cd 的效率，该模式可推荐用于农田 Cd 污染土壤的修复。
