Divergent soil health responses to long-term inorganic and organic fertilization management on subtropical upland red soil in China

•Infertile red soil benefited from 23 years of organic and inorganic fertilization.•Applying pig manure had overwhelmingly positive effects on soil fertility.•Use of pig manure fertilizer increased contamination risk for Cu, Zn, and Cd.•Micronutrients properly added to fertilizers further enhance overall soil health.•The comprehensive assessment revealed the development trends of soil health.