不同降解地膜对河套灌区向日葵农艺性状及产量的影响

Effects of different degradable plastic films on sunflower agronomic traits and yield formation in Hetao irrigation area

针对地膜残留污染已经成为河套灌区主要的面源污染物的问题,试验以5种可降解地膜为供试材料,在内蒙古河套灌区向日葵主产区开展了田间试验。结果表明:与不覆膜的对照相比,覆膜均促进了向日葵的生长,并使其产量增加,增产幅度为3.4%~31.8%;由于配方不同,5种降解膜的降解特性以及对向日葵生长及产量的影响存在显著差异(P<0.05);快降膜和白降膜降解速度最快,诱导期分别为56d和58d,其次是中降膜和黑降膜,诱导期均为68d,慢降膜降解速度最慢,诱导期为78d;在全生育期内,除慢降膜外,其他降解膜均完全降解;从向日葵的生长发育情况看,与常规膜相比,降解地膜对向日葵出苗率和叶片数无影响,慢降膜增加了株高,快降膜和白降膜降低了株高、茎粗和花盘直径;从产量结果看,与常规膜相比,慢降膜、中降膜、黑降膜无显著差异(P>0.05),快降膜和白降膜减产达到了显著水平(P<0.05)。综合考虑,诱导期在68d以上、完全降解期在138d以内的中降膜和黑降膜与当地的气候条件和向日葵生长匹配较好,既可以获得较高产量,也可以完全降解无残留。

In order to solve the problem of the residual pollution of plastic film that has become the main non-point source pollutant in Hetao irrigation area,five kinds of degradable plastic films were tested in the field experiments in the main sunflower producing areas of Hetao irrigation area.The results showed that film mulching promoted the growth and yield formation of sunflower compared with non-film mulching with the yield increase ranging from 3.4% to 31.8%.The degradation characteristics of five biodegradable membranes and their effects on sunflower growth and yield formation were significantly different due to the different formulations (P<0.05).The results of surface coverage test showed that the degradation rate of fast film and white film was the fastest,with the induction period of 56 days and 58 days,respectively,followed by middle film and black film,with the induction period of 68 days,and slow film was the slowest,with the induction period of 78 days.All degradable membranes except slow film were completely degraded during the whole growth period.Compared with the ordinary PE film,the degradable plastic film had no effect on the emergence rate and the leaf number of sunflowers.Slow film increased the plant height,while fast film and white film decreased the plant height,the stem diameter,and the flower disc diameter.There was no significant difference in the yield of slow film,middle film,and black film compared with the PE film (P<0.05).The yield of fast film and white decreased significantly (P<0.05).In summary,the middle film and black film matched well with the local climate conditions and the sunflower growth,which could not only obtain higher yield but completely degrade without residue.