Soil quality normally indicated soil fertility quality, soil environment quality and soil health quality. Due to the long-term intensive management from farmers and industrial activities, more and more agroforestry lands are suffering soil degradation, including soil fertility decrease, soil heavy metal pollution and soil microbial communities changes, which further influence the plant growth, quality and food safety. Since soil plays the directly important role in the healthy plant/crop growth, protective measures should be carried out. In order to explore the soil-plant correlation under the soil quality degradation, this special issue will mainly focus on the following topics:

New methodology and index to reveal soil quality degradation of agroforestry ecosystem;

Crop quality and safety assessment under the threat of soil quality degradation;

The transfer and transportation of nutrients, toxic elements etc. in the soil-plant systems of subtropical region;

The protective measures which could be used to improve the soil quality degradation such as heavy metal pollution, nutrients imbalance, soil erosion etc.