Effects of the Implementation of Rejuvenation Technologies on the Soil in the Rhizosphere of Ancient Trees and the Growth of New Shoots ——A Case Study of Ancient Ginkgo biloba in Pinghu City

The rejuvenation and protection of an ancient Ginkgo biloba tree in Pinghu City was carried out through the implementation of rejuvenation techniques, such as the masonry of drained and ventilating ditches, soil excavation and root treatment, allocation of back filled earth and replacement of soil, branch pruning and trimming, tree body decaying, tree body filling, hoop fixing and support protection, the changes of soil quality and the growth of new shoots before and after the implementation of rejuvenation techniques were monitored and analyzed. The results showed that the contents of soil organic carbon and total nitrogen increased by 50.9% and 60.1% (P<0.05), and the ratios of carbon to phosphorous, carbon to potassium, nitrogen to phosphorous, nitrogen to potassium in soil were also significantly increased (P<0.05). The volume weight of soil decreased by 31.3% (P<0.05), while the total porosity increased by 65.1% (P<0.05), and the number of significant correlations among the soil indexes decreased from 8 pairs to 4 pairs. The growth of new shoots in ancient Ginkgo biloba was significantly increased by 28.9%~34.7% (P<0.05).