In a previous article, we reported that a local variety of alfalfa (Medicago sativa L. cv. Aohan) had high potential to be a pioneer plant for ecological restoration in the Horqin Sandy Land, China. The plantation of ...In a previous article, we reported that a local variety of alfalfa (Medicago sativa L. cv. Aohan) had high potential to be a pioneer plant for ecological restoration in the Horqin Sandy Land, China. The plantation of Aohan significantly improved the organic matter, clay, total carbon and nitrogen contents of the soils. In this study, we investigated the physical properties such as dispersion ratio, water-stable aggregates content, and the soil microbiomes, five years after alfalfa establishment in the same study site. We found no significant difference in the dispersion ratios between the soils before and after alfalfa establishment, and all the soils at the study site were erosive. Water stable aggregates mainly distributed in 96%, suggesting that it would take longer time for improving soil structure. However, large-size aggregates (2 - 5 mm) content was slightly higher in the alfalfa planting plots. This slight increase is presumed to have long-term importance for soil and ecosystem recovery in semi-arid areas like Horqin Sandy Land. Moreover, we also found that Actinomycetes dominated the microbial community in both bulk and rhizosphere soils, and two kinds of rhizobia, Bradyrhizobium and Sinorhizobium fredii, were identified in the rhizosphere soil.展开更多
文摘In a previous article, we reported that a local variety of alfalfa (Medicago sativa L. cv. Aohan) had high potential to be a pioneer plant for ecological restoration in the Horqin Sandy Land, China. The plantation of Aohan significantly improved the organic matter, clay, total carbon and nitrogen contents of the soils. In this study, we investigated the physical properties such as dispersion ratio, water-stable aggregates content, and the soil microbiomes, five years after alfalfa establishment in the same study site. We found no significant difference in the dispersion ratios between the soils before and after alfalfa establishment, and all the soils at the study site were erosive. Water stable aggregates mainly distributed in 96%, suggesting that it would take longer time for improving soil structure. However, large-size aggregates (2 - 5 mm) content was slightly higher in the alfalfa planting plots. This slight increase is presumed to have long-term importance for soil and ecosystem recovery in semi-arid areas like Horqin Sandy Land. Moreover, we also found that Actinomycetes dominated the microbial community in both bulk and rhizosphere soils, and two kinds of rhizobia, Bradyrhizobium and Sinorhizobium fredii, were identified in the rhizosphere soil.
