Highlight:
(1) Protected cultivation (PC) soil HMs over-standard rates are prominent in China.
(2) Overall PC area is slightly contaminated, Yunnan and Henan are more harshly affected.
(3) Cu and Zn accumulation is derived from anthropogenic agricultural activities.
(4) Pb, Cd, and As accumulation is derived from the soil parent material.
(5) Available Cu, Zn, As amounts showed a linear correlation with planting years.