Phosphorus Retention And Loss In Three Types Of Soils With Implications For Geographical Pattern Of Eutrophication In China

Phosphorus (P) loss from soil to water bodies is an important process associated with eutrophication of lakes and reservoirs. Phosphorus concentration in China's waterbodies changes geographically, increasing substantially with latitude. It is assumed that the geographical pattern results from change in soil retention and loss features of P. To test this assumption, we designed a soil column leaching experiment to measure the P retention capacity of three common types of soils in China: red, black and loess. Results showed that red soil possessed a much higher P retention capacity than black and loess soils. Red soil retained P primarily through binding by aluminium and iron, with half of the total retained P contributed by iron binding. Phosphorus loss in all three soils was influenced by pH of the used acid solution and the leaching rate. Specifically, acidification tends to promote soil P loss, whereas leaching rate decreases P loss.