Abstract:
Biodegradable plastic film is an important way to solve the problem of plastic film residue pollu-tion. It has great potential for agricultural development, but different biodegradable plastic films were different in different ecological regions and affected its popularization and application. In this paper, comparative field experiments were carried out among three cultivation methods, 9 biodegradable films cultivation, ordinary PE (CK1) film cultivation and open field cultivation (CK2), from field degradability of plastic film, soil thermal insulation, crop growth, yield and its composition factors, residual plastic film coverage and so on. The result showed that the degradation of the selected four kinds of biodegradable plastic films GS05, GS09, GS10 and GS03 was slow at the early growth stage of maize and quicker in the middle and later stages, and the growth adaptability of maize was better. The soil temperature in the whole maize growth period at 10 cm soil layer from emergence to jointing stage, from tasseling to filling stage compared to CK1, decreased from 0.1˚C to 0.5˚C, from 0.5˚C to 1.0˚C and from 0.2˚C to 0.5˚C. The difference of maturity from harvest to maturity was improved by −0.9˚C - 0.6˚C. Emergence rate, plant height, stem diameter, panicle length, grain number perpanicle, 1000-grain weight compared to CK1 increased by −3.3 - 3.4 percentage points, −16.7 to −3.5 cm, −0.2 to −0.3 cm, −2.7 to 0.0 cm, −33.7 to −16.4, −17.3 to −7.0 g; maize yield was 12,664.5~14,493.0 kg/hm2, which was 0.6~13.1% less than that of CK1. The results showed that the effect of four biodegradable mulches and ordinary mulching film on maize yield was not significant, which was 86.3% - 113.1% higher than that of CK2, and the difference was significant. The coverage of the four kinds of biodegradable mulching films was 25.8%, 64.3%, 24.4% and 51.5% respectively when corn was harvested, which was 3.3%, 7.4%, 6.2% and 16.5%. These results indicated that the degradation characteristics of the four biodegradable plastic mulch basically accorded with the environmental requirements of maize growth in the high elevation irrigation area of northern China, and could replace the traditional mulching film.