Abstract: A pot experiment with arsenic-contaminated red soil was conducted to study the effects of applying pig dung and chicken manure on the growth and arsenic absorption of pakchoi (Brassica chinensis), and on soil available arsenic. Applying pig dung and chicken manure to the arsenic- contaminated red soil increased the biomass of pakchoi to some extent. Comparing with the control, applying pig dung increased the pakchoi biomass significantly (P<0.05). The soil available arsenic content after applying pig dung increased by 394.9%-1033.6% (P<0.05), and that after applying chicken manure increased by 30.4%-94.1%. Organic fertilization promoted the arsenic absorption of pakchoi, with the arsenic uptake after applying pig dung increased by 20.7%-53.9%. The application of pig dung and chicken manure to arsenic-contaminated red soil could somewhat increase the soil available arsenic content and the arsenic uptake by crops,and thus, increase the risks of agricultural product quality and environment.

Key words: pig dung, chicken manure, soil available arsenic, pakchoi (Brassica chinensis), soil total nitrogen, inverse distance weighting, ordinary Kriging, universal Kriging, geographically weighted regression.