关键词: 玉米, 耐候地膜, 水热效应, 产量, 耐候性评价

Abstract:

Limited water and heat resources in the dry farming areas of central Gansu restrict maize growth and development. The technology of full-film double-ridge furrow sowing can solve the problem of water and heat constraints and make maize as a major local crop, but the technology also causes serious film residue pollution. To introduce the weather resistant and easily recycled plastic mulch film, a field experiment was conducted to investigate the effects of different PE mulch film (T1, T2, T3 and T4, among them, T1, T2 and T3 were weather resistant mulch film, T4 was traditional PE mulch film) and degradable mulch film T5 on soil water and heat conditions, maize photosynthetic properties and yield. The results showed that soil water content of T1, T2 and T3 were similar to that of T4 during the whole growing period of maize, but compared with T5, T2 could increase the soil water content of the 30-50 cm soil layer at the seedling stage. There was no significant difference of average soil temperature in 5 and 10 cm soil layer during the whole growth period, but the average soil temperature of T5 in 15 cm, 20 cm and 25 cm soil layers was 0.5-1.4 °C, 0.3-1.1 °C and 1.0-2.3 °C lower than that of T1, T2, T3 and T4, respectively. The leaf area index of T1, T2, T3 and T4 was significantly higher than that of T5 at jointing stage, big trumpet stage and filling stage. Compared to common plastic mulch film, T1 significantly improved the maize photosynthetic characteristics at big trumpet stage. Compared to that of T5, the grain yield of T1, T2, T3 and T4 was increased by 40.41%, 45.04%, 27.41% and 32.80%, respectively. There was no significant difference of the biological yield among the treatments, and there was no significant difference between weather resistance plastic film T1, T2 and T3 and traditional PE mulch film T4. After maize harvest, the longitudinal tensile load of weather resistant plastic film was significantly higher than that of T4, and the longitudinal tensile load, transverse tensile load and longitudinal fracture nominal strain of T1 were the largest, and its recovery was more easier than other plastic mulch film. Therefore, the application of T1 in dry agricultural areas of central Gansu can have similar hydrothermal effect with T4, and the yield of maize is also equivalent. In addition, film residue of T1 can be easily recycled after maize harvest, which reduces the pollution caused by film residue. However, due to the limited effect of temperature increase, the degradable film (T5) will reduce the yield of maize.

Key words: maize, weather resistant plastic film, hydrothermal effect, yield, weather resistance evaluation