Application of UVA in Soil and Water Conservation: Preparation of Planting Materials for UVA

Taiwan is an island-type country with possible debris flow in the mountains. Therefore, strengthening soil and water conservation work to prevent natural disasters is a continuous and necessary work. However, people and machines are not easy to reach the bare land on the mountain, so the planting is difficult to do. In this study we intend to develop planting materials that can be carried and spread by UAV for the purpose of carrying out the work of bare ground planting in the mountains. A biodegradable polymer, polyacrylamide (PAM), was chosen as the matrix. By combining other materials, such as grass seeds, fertilizers and other additives, the seeding granules were produced for drone throwing. Because the matrix affects the distribution of the granules on the ground after throwing, in this study the morphology of PAM on silica surface was observed by an optical microscope (OM) and an atomic force microscope (AFM) to understand the interaction between the matrix and the ground. And in order to understand the effects of the matrix on the seed germination, ryegrass seeds were selected for the germination test. OM images show that the PAM film on the glass slide expands outward from the center and branches therefrom, showing a dense dendritic structure, and the closer to the center point, the more the dendritic structure. AFM images depict that the granular structure formed at the central portion is large, the pores between the granular portions are also large, and the granular structure formed at the interval portion is small and dense. PAM solutions on the glass slide do not immediately flow outward due to the large viscosity. However, the evaporation of water induces the stretch of PAM molecule, and makes it gradually deposits and adsorbs on the glass slide. All the facts give the evidences that PAM can be spread on silicon oxide and the adsorption effect is very good. The germination experiment showed that the planting granule formula used had no effect on the germination of ryegrass, and had the effect of promoting growth of the germinated young grass. Finally, the artificial and UVA throwing granule tests showed that the planting granules could successfully attached to the ground or slope, and the grass germinated and grew well.