zone of saturation

例句：

1. 1. The soil in the area has a high level of organic matter, which is essential for plant growth.
   该地区的土壤含有大量有机物质，对植物生长至关重要。
2. 2.In the zone of saturation, the rate of photosynthesis increases significantly.
   在饱和区，光合作用速率显著增加。
3. 3. The researchers found that increasing the amount of fertilizer in the soil could lead to an increase in the zone of saturation.
   研究人员发现，增加土壤中的肥料量可能会使饱和区面积增大。