Abstract: The distribution changes of soil pH, organic matter content and heavy metal pollutants in paddy fields and dry fields under the paddy-upland rotation were studied. The results showed that the pH and organic matter content in paddy fields were generally higher than those in dry fields, accounting for 85.7% and 76.2% respectively. The contents of heavy metals such as As, Pb, Cu, Ni and Zn were higher in dry fields than in paddy fields, accounting for 61.9%, 88.1%, 64.3%, 76.2% and 69.0%, respectively. Only Cr content was higher in paddy fields than in dry fields, accounting for 71.4%. Compared with dry fields, the soil pH median value in paddy fields had increased by 0.55, with an increase of 8.0%, the soil organic matter median content in paddy fields had increased by 9.6 g/kg, with an increase of 35.6%, and the median content of As, Pb, Cu, Ni and Zn in paddy fields had decreased respectively 8.2%, 9.2%, 11.7%, 7.8% and 4.8%, while Cr median content increased by 14.3%.

Key words: soil, paddy-upland rotation, agricultural land, environmental monitoring, pH, organic matter, heavy metal