Changes in profile distribution and chemical properties of natural nanoparticles in paddy soils as affected by long-term rice cultivation

Systematic studies on the genesis, properties, and distribution of natural nanoparticles (NNPs) in soil remain scarce. This study examined a chronosequence continuous paddy field land use for periods ranging from 0 to 1 000 years determine how NNPs changed at early stages genesis eastern China. Soil samples were collected coastal reclaimed fields that cultivated 0, 50, 100, 300, 700, years. Natural isolated characterized along with bulk (< 2-mm fraction) selected physical chemical properties. The NNP content increased increasing cultivation age 60 g m −2 year −1 , which was related decreasing electrical conductivity (172–1 297 µS cm ) zeta potentials (from –22 –36 mV) age. Changes several such as pedogenic iron oxide total organic carbon contents, consistent those soils across chronosequence. Notably, changes obvious illustrated active weathering, pedogenesis, potential impacts microbial community. Redundancy analysis demonstrated most important factor affecting contributing 60.7% variation. Cluster principal component (PCA) revealed splitting into groups 50–300 700–1 years, indicating rapid evolution after an initial period desalinization (approximately 50 years). Overall, this provides new insights during pedogenesis predicting their influences agriculture ecological risks over millennial-scale rice cultivation.