Behavior and environmental impact of soil dissolved organic matter

Dissolved organic matter(DOM) is defined as organic matter that becomes absorbed in water. Irrespective of the fact that considerable disagreements remain on the character,composition and classification of DOM in terrene ecosystems, research has nonetheless proven that DOM is an active and important chemical component of natural systems.Once DOM enters the soil, chemical processes such as adsorption,desorption,transfer, transformation, etc. occur and consequently induce significant impact on the soil and environment. On the one hand, DOM combines with soil colloids to form organic-inorganic combos which sequentially improve soil quality. On the other hand, DOM aggregates with nutrients and metal ions and combines with original soil colloids, making them more easily releasable into soil solutions. Besides, DOM produces nutrient ions through decomposition and thus enhances soil fertility. These processes do not only result in nutrient leaching risk causing loss of soil nutrients and water eutrophication, but also enhance heavy metal eluviation by DOM activation effect on heavy metal ions in the soil and consequently exacerbate soil heavy metal toxicity. Therefore, DOM has increasingly become the research focus in the fields of agrology,environmental science,ecology, etc. in recent years due to its myraid effects on soil and the environment.