Abstract: Rice seedlings in some paddy fields of Wulao Village, Wanghua District, Fushun City in the spring of 2017 wilted after irrigation with water from Yangbai River. In situ investigation of soil and irrigation water regarding salinity, polycyclic aromatic hydrocarbons (PAHs) and heavy metals was conducted, followed by experiment with factorial treatments of soil and irrigation water, to reveal the impacts of salinity and organic pollutants from soil and water on the growth of rice seedlings. The results showed that salinity of water and paddy soil exceeded the level of agricultural standard. The concentrations of heavy metal Hg and PAHs in some fields were higher than the standard level of agricultural land, which partially accounted for the rice wilting. Results from the crosssimulation experiment showed that the wilting rate of rice seedlings in contaminated field soil irrigated with water from Yangbai River, artificial saline water or tap water was 89.7%, 79.3% and 0.67%, respectively. In contrast, the wilting rate of seedlings in uncontaminated field soil irrigated with Yangbai River water, artificial saline water and tap water was lower, with wilting rate of 42.3%, 34.7% and 0% respectively. Organic contaminants discriminated the Yangbai River water and artificial saline water under the same salinity, and PAHs and salinity were the main indicators discriminating the contaminated and normal soil in study area. Our results indicated that salinity of paddy field soil was relatively high after longterm irrigation with lesssalty water from Yangbai River, but quickly increased to the unfavorable range of 0.25%-0.58% after a sudden rise in salinity of irrigation water (0.35%), leading to the wilting of rice seedlings. Organic contaminants (PAHs) accumulated in the topsoil further aggravated the wilting of rice seedlings under excess salinity in water and paddy soil.

Key words: dynamics of lake area, spatial pattern, Qinghai-Tibetan Plateau, GEOMOD model