Abstract: 【Objective】It is to prepare Pseudomonas stutzeri microsphere preparation with sodium alginate as carrier and establish the application conditions of the preparation for degrading indoxacarb in farmland soil. 【Method】The best formulation was obtained by the method of micro droplet embedding and single factor optimization, and the stability and degradation activity of the preparation were tested to determine the field application conditions. 【Result】The preparation was composed of 3% sodium alginate, 2% calcium chloride and 80 g?L^-1degrading bacteria with a particle size of 3.0 mm, high degrading activity and good stability. Scanning electron microscopy showed that the degrading bacteria were evenly distributed in the alginate microspheres, and the morphology of the bacteria was normal. The degradation rate of indoxacarb reached more than 95% in the soil with pH 5.0-9.0 and 10-40℃, and the release performance was not affected by the soil type. Field experiments showed that the half-life of indoxacarb in soil was significantly shortened to 7.9-8.8 d when the dosage of indoxacarb was 450 kg?hm^-2. 【Conclusion】When the concentration of sodium alginate was 3%, the concentration of calcium chloride was 2%, and the amount of entrapped bacteria was 80 g?L^-1, the size of the microspheres was uniform, the mechanical strength was moderate, and the mass transfer performance was good. The distribution of degrading bacteria in alginate microspheres was uniform and the morphology of bacteria was normal. The results showed that the release ability and stability of the preparation were good, little affected by environmental conditions, and good storage stability. The field experiment showed that the half-life of indoxacarb in soil could be significantly shortened to 7.9-8.8 d when the dosage of indoxacarb was 450 kg?hm^-2. The field application effect was good, which provided technical and product support for bioremediation of soil indoxacarb pesticide residue pollution, and had further optimization potential and broad application prospect.

Key words: pesticide residue, bioremediation, sodium alginate, degrading bacteria preparation, indoxacarb