关键词: 地膜厚度, 一膜三年覆盖, 水分利用效率, 产投比, 地膜残留, 玉米

Abstract:  In order to study the effects of three-year mulching with different thickness of plastic film on soil water and heat effects, maize yield and film residue, field experiments were conducted with three-year mulching of plastic film. In the field experiment, four thickness levels of the mulch (0.008, 0.010, 0.012, 0.015 mm) were randomly designed. The results showed that: ① The mulch film with thickness of 0.012 mm and 0.015 mm had good effect of increasing temperature and preserving the moisture of the soil after many years. Compared with one-year mulching CK, water consumption during the growth period of film mulching with thickness of 0.012 and 0.015 mm only increased by 1.96% and 1.14%, and the soil temperature from corn sowing to jointing stage only decreased by 0.74 and 0.71 ℃. ② Under three-year mulching, the growth of crops was affected, and the yield and water use efficiency of maize reduced. Yield and water use efficiency under 0.008 mm thickness mulch were significantly lower than that of CK, 13.24% and 18.12%, but the efficiency under the thickness of 0.010, 0.012 and 0.015 mm was close to that of CK, and only decreased by 2.27%~4.09%, 2.85%~8.36%. ③ Under three-year mulching, the input cost effectively reduced, and the ratio of output to input of maize significantly increased by 13.73%, 25.00%, 26.47% and 25.49% compared with CK. ④ Three-year mulching significantly reduced the film residues, which was 55.74%~61.42% lower than CK, but the film with thickness of 0.008 and 0.010 mm was fragile and difficult to recover, making the residual coefficient of plastic film as high as 35.60% and 32.97%. When the film thickness increased to 0.012 and 0.015 mm, the residual coefficient decreased to 21.99% and 19.81%. In conclusion, the application of plastic film with thickness greater than 0.012 mm in multi-year mulching could ensure maize yield, improve water use efficiency and the ratio of output to input, and effectively reduce residual film pollution.

Key words: film thickness, three-year mulching, water use efficiency, ratio of output to input, film residues, maize