1、Experiment site: Luancheng District, Shijiazhuang City, Hebei Province (37 ° 53'N, 114 ° 41'E) and Nanpi County, Cangzhou City, Hebei Province (38 ° 06 ′ N, 116 ° 40 ′ E)；2、Time：2016-20173、Experimen
To assess the effects of physical, chemical and biological soil manipulation (or inputs) on soil organic carbon in relation to changes in long term crop yields and quality.
