Abstract:

In order to evaluate the farmland applicability and extension feasibility of biodegradable mulch film covering garlic, this study investigated soil temperature increase effect, soil moisture conservation effect and degradation property of four kinds of biodegradable mulch film, including 0.006 mm (A), 0.008 mm (B), 0.01 mm (C) and 0.01 mm (D), on the growth and development of autumn sowing garlic, with bare ground (CK₁) and two types of PE mulch film (CK₂ and CK₃) as the controls. The results showed that the order of the induction period of the four kinds of biodegradable mulch film was D>C>B/A, and the functional period ranged from 210 days to 140 days. Mulch film C and D could meet the requirements of autumn sowing garlic in southern Shandong for the functional period of mulch film being no less than 180 days. The soil moisture content of PE mulching was higher than that of biodegradable film mulching, and for the same type of mulch film, the greater the film thickness, the better the soil moisture conservation effect. Soil accumulated temperature decreased in the order of CK₃, D, C, B, A, CK₂, and CK₁. Compared with the bare land treatment, film mulching treatments increased the number of roots by about 30% and garlic yield by 28.06%-34.69%, but there was no significant difference among the film mulching treatments. The bolting stage of garlic covered with biodegradable mulch film was 2-3 days later than that covered with PE film. In conclusion, the biodegradable mulch film can increase soil temperature, preserve soil moisture and promote the growth of garlic, and the effects are equivalent to those of common PE mulch film. The biodegradable film can be used as an effective way to replace the common PE mulch film to solve the pollution problem in garlic fields.

Key words: garlic, biodegradable mulch film, temperature increase, soil moisture conservation, induction period