| Since introduction covering technology of soil-film from Japan, it was in a rapid development in our country. At present, the covering area is over 14 million hectares, the consumption had reached 100 million tons.The covering area will be more than 20 million hectares in 2010. Currently the majority using of film is polyethylene or PVC, it is toxicity and hard to be degradated. The debris left in the soil can also not be degradated and not be absorbed by crops.People have given high light on the wasted film. In this test we produced soil-film by non-woven technology. We discussed the material selection of no pollution and all-degradable, program in proportion ,and the field performance test, then got the best program.We used wasted materials in industries such as flax and silk to produce soil-film. Flax is natural cellulose fibre, silk is natural protein fibre, they all could have natural degradation, and degradated products did not pollute the environment, the decomposed protein of silk could improve soil characteristics and soil nitrogenous content.We used two different methods to produce soil-film. The first was mixed. We produced it according to different proportion of flax and silk, unit gram and adhesive concentration by orthogonal analysis. Then we had some physics tests such as strength, thickness and other performance, got the best program, weight proportion of flax and silk was 96:4, unit gram was 35g/m~2, adhesive concentration was 8%. The performance of samples was broken strength 30N, thickness 0.1148mm, moisture regain 6.7%, water permeability 2,217g/(m~2·h).The second was impregnation process. We impregnated flax soil-film in silk solution with different concentrations. Then we had some tests after drying. The best sericin concentration was 15‰, broken strength was 33N, thickness was 0.1203mm, moisture regain was 3.9%, water permeability was 2,165g/ (m~2·h). Put these two soil-film to have covering testing in field, and compared with plastic film. Heat preservation tests showed that soil-film in natural fibre was better than plastic film, it had improved 5℃,but it was slight lower than plastic film. Emtropy preservation tests proved that it could reduce moisture evaporation that covered with non-woven cloth. Moisture evaporation with mixed non-woven cloth was 20% less than plot. Moisture evaporation with sericin was 26.2% less than plot, while plastic film was 49.5% less than plot, its emtropy preservation was obvious. Degradation tests proved that they all could be degradated in natural. After 60 days degradation, the degradation rates of soil-film by mixed and impregnation process were 18.1% and 20% respectively. We could see bundle flax fibre decomposed into single fibre through SEM. Infrared spectrogram showed that the large molecules chain was broken, the large molecules brought to depolymerization. It would not harden soil. Some degradated products could enhance soil nitrogen content of soil. After 60 days degradated, nitrogen content had increased 4.3% and 11.8% respectively.Tests shown that non-woven film with natural fibre in comparison with plastic film, the former was larger in thickness, higher in broken strength, better in water, permeability, heat and emtropy preservation, but it was less than the latter in these performance. While the latter could not be degradated and not increase soil fertility. Compared with these two non-woven soil film it had no obvious distinction in heat and entropy preservation. However the other performance of film impregnated with sericin solution was superior than mixed film, it had lower price, so it was well in popularization and application.
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