Effect of treatment patterns of used plastic film in field on oil flax physiological index and yield

Field experiments were conducted to investigate effective reuse patterns of used plastic films in field and its effect on oil flax production stability and yield. The study compared the influences of 5 used plastic film treatment patterns on oil flax leaf SOD activity, MDA content, Pro content, soluble protein content and yield components and yield. The 5 patterns included field-kept film and no-tillage sowing the next year (T1), field-kept film with earth mulching and no-tillage sowing the next year (T2), field-kept film with straw mulching the current year and no-tillage sowing after straw clearing the next year (T3), field-kept film with replacement by new plastic film and no-tillage sowing the next year (T4) and film collection with land preparation and new plastic film mulching just after harvest and sowing the next year (T5). The treatment of film collection just after seasonal harvest with land preparation and no-mulch sowing the next year (T6) was used as the control. The results indicated that keeping used plastic films in field till the next year had the same film mulching effect on soil temperature, moisture and nutrient. It did not only enhance SOD activity and soluble protein content, but also coordinately regulated MDA and Pro contents. It also increased per-plant capsule number, one-thousand-grain weight and crop yield. Yields of T1, T2, T3, T4 and T5 increased by 10.05%, 17.52%, 29.79%, 40.67% and 22.16%, respectively, over the control. The treatment of keeping film in the field until the next year with new plastic film mulching and no-tillage sowing the next year pattern (T4) was the optimal used plastic film treatment method in regions with plastic film mulching cultivation in China. It also offered the best choice for the highest oil flax yield.