Variations in soil characteristics due to a paddy field land consolidation project in Mazandaran Province

This study was carried out to investigate and monitor variations in soil characteristics as a result of a paddy field consolidation project executed in Mavaremkola, Ghaemshahr City, Mazandaran. For this purpose, soil characteristics were evaluated before and after the consolidation project in two large plots: Plot 1, where soil was displaced at a low to moderate rate, and Plot 2, where soil was displaced at a high rate. Meshes 10×10 m were created along the longitudinal axes of the plots from which samples of the composite soil were collected before and after land leveling operations to determine their physico-chemical characteristics according to the standard methods recommended by Soil & Water Research Institute (Iran). Results revealed changes in certain soil characteristics as a result of the land leveling operations such that significant reductions were observed in phosphorus and potassium contents of the soil from Plot 1 (with low to moderate soil displacement) but none in that from Plot 2 (with high soil displacement). The operations were found to induce significant decreases in soil organic content in both plots. This is while soil EC increased and pH decreased in both plots but trace micronutrients such as iron, manganese, zinc, and copper in either plot remained unaffected as a result of land leveling operations. The relative reduction in organic carbon observed in this study was attributed to the non-standard land leveling of paddy fields and the use of high-quality topsoil for making access roads and plot borders, indicating that the consolidation project led to a relative decline in soil quality.