The practical application of in situ remediation techniques requires an understanding of the dynamic changes in soil enzyme activity as indicators of soil fertility and health. Experiments were carried out in paddy soils co-contaminated with cadmium (Cd) and arsenic (As) at low (L) and high (H) levels. A calcium and iron (Ca[sbnd]Fe)-based amendment (limestone + iron powder + silicon fertilizer + calcium‑magnesium-phosphate fertilizer) was applied to the soil at concentrations of 0, 450, and 900 g·m−2 (labeled CK, T1, and T2, respectively), ...
