天然土壤 meaning in English

natural soil

If the natural soil does not contain these proportions, it should be corrected by adding the material which is short .
如果天然土壤的组成不符合上述比例，则应掺加它所缺少的材料来进行修正。
Further , research clearly shows that as soil nutrient levels are maintained , as crop yield levels are increased and more residues are returned to the soil , productive capability continues to increase and the natural resource of the soil is protected
再者，研究清楚地表明，如果保持住土壤肥力水平，作物产量增加，更多残茬还田，生产能力会持续上升，天然土壤资源也得以保护。