Water release in composite coating of Caragana korshinskii seeds.

Aerial-seeding afforestation, as a quick, effective measure, has become an important approach for vegetation restoration and reconstruction in hinterland of Mu Us Sandy Land of northern China. However, the low survival rate of seedlings is a problem that needs to be resolved urgently. We selected Caragana korshinskii as the material, and set different combinations of coating agents by orthogonal experiment to pellet Caragana korshinskii seeds. After analysis of the germination rate, seedling growth, and the physical properties of each group, the optimum formula was obtained as 1.5% ethyecellulose, ratio of attapulgite clay to talc 2∶1, 10% super absorbent polymers, and the pelleting ratio 1. And the pelleted seeds had water-absorbing ability. After pelleting, eudragit, screened out as the film-forming agent, was coated outside of pelleted seeds as 10% thick film. The film was efficient and could be dissociative at the appropriate soil moisture content. Field planting experiment in Mu Us Sandy Land showed that the seedling rate was improved significantly by 22% after pelleting the Caragana korshinskii seeds with super-absorbing polymers. And the result was much better when coating the pelleted seeds with our film material. Therefore, this complex of film-coated seeds can provide new ideas for aerial seeding in Mu Us Sandy Land.