Improvement of Plantation Soil by Intercropping Tea Plants with Green Manures

  Objective  Effects of intercropping green manures with tea plants on the chemistry and bacterial community of plantation soil were analyzed for ecological improvements.

  Methods  Changes on the soil pH, heavy metals, and bacterial diversity and community were monitored after various intercropping treatments.

  Results   The Lupinus perennis (L)-Brassica campestris (B)-Chamaecrista rotundifolia (C) intercropping with tea plants did not improve but, in fact, lowered the soil pH. However, significant acidity mitigation was achieved by BC- or LB-intercropping with tea plants in the pot experiments. LB-intercropping also significantly reduced the content of heavy metals including Cd and Hg. The bacterial diversity and community structure of the intercropped soil were significantly changed with Proteobacteria becoming the most abundant phylum and Actinobacteria decreasing to less than 20% of the total population in the treatments with L, LB, or LBC. The intercropping also significantly increased Cyanobacteria population to more than 1%, in comparison to 0.1%-0.3% on control.

  Conclusion   Intercropping L. perennis and B. campestris with tea bushes was conceivably to enable improvements on pH, Cd/Hg contents, and microbial community of the soil at plantations.