[Residue and Degradation of Roxarsone in the System of Soil-Vegetable].

The field experiment was developed for simulating the residues, transformation and degradation in soil-vegetable system of Roxarsone contained in organic fertilizer. Under the treatment, the yield of Brassica chinensis decreased in low Roxarsone concentration with a decline by 15% to 32% compared with the control group; there had an accumulating role of vegetables to arsenic, and the root was the main part; total content of arsenic in the soil was positively correlated with the dose of the applied Roxarsone; total arsenic in soil first increased and then decreased with the planting time prolonged and peaked at 12.94 mg x kg(-1), while the level of inorganic arsenic in the soil stabilized after 30 d, which accounting for 66.75% to 98.56% of the total arsenic; there existed a positively significant correlation of total arsenic content between the Brassica chinensis and the soil as well as the arsenic enrichment factor of vegetables; the degradation rate of Roxarsone in soil was slow, there was still some Roxarsone remained in soil after 45 d when added the organic fertilizer which containing Roxarsone with the dose higher than 5 000 kg x hm(-2); Roxarsone could significantly increase the number of bacteria in the soil, and low concentration showed an inhibited role in the growth of fungi and actinomyces, while high concentration of Roxarsone promoted the growth.