Abstract:

Tidal flat reclamation is one of the most important methods for coastal countries and areas to increase the land and reconcile the conflict between human and land Largescale reclamation activities have extremely severe impact on the tidalflat soil environment, and then affect the carbon, nitrogen, phosphorus, potassium and other soil nutrient cycle Studying the changes of soil environmental has important implications in this area The tidal flat land resource of Jiangsu Province is abundant and the reclamation activities have been lasting for many years, and these reclamation activities will continue to exist for a long period of time in the future Based on the distribution of soil pH value, organic matter content and available nutrients of reclamation soils with different reclamation years in Jiangsu Rudong coastal intertidal zones, the relationships between pH value, soil organic matter and available nutrients were analyzed The results indicated: firstly, soils of Rudong intertidal reclamation zones were slightly alkaline to alkaline, and available potassium was abundant while the contents of other soil available nutrients were below the average level of Rudong county With increasing reclamation years, a series of soil improvement measures were adopted, and pH value decreased and the surface soil nutrients increased Secondly, at the beginning of the reclamation, there was positive correlation between soil pH and organic matter, and negative correlation between soil pH and available phosphorus, however it was the opposite in the zone with longer reclamation years The correlation between pH and alkali solution nitrogen was negative, and pH was negatively related to available potassium except for the reclamation zone with 20 years Finally, in the reclamation zone that was reclaimed long years ago, the relationship between soil organic matter and available nutrients was much more significant than that in the initial reclaimed zones Tenyearreclamation was the turning point of the correlation between organic matter and alkali solution nitrogen, available potassium These results suggest that the tidal flat reclamation not only affected the distribution and absolute content of soil pH, organic matter and available nutrients, but also had a significant impact on the relationships among them With increasing reclamation year, the human activities such as cultivation, irrigation, fertilization, are deeper and deeper, and the soil gradually is evaluated from natural coastal saline soil to agricultural soils, and the relationship among soil elements gradually becomes closer to general farming soil