A massive oak claims its ground for 200 years or more, outcompeting all other would-be canopy trees by casting a dense shade and drawing up any free water in the soil.
Growing organically keeps soil in its natural state and protects the ground as well as our water.
而有机食品的种植不会改变土壤的天然性质，因而可以保护我们的土壤和水源。
3
Though it is di? Cult to grow trees in the saline-alkali soil, the ground cover and wetland vegetation are rich and vary in response to subtle changes in the water table and PH values.