Soil temperature and soil water potential under thin oxodegradable plastic film impact on cotton crop establishment and yield

摘要

Field experiments were undertaken to determine the effect of oxodegradable thin film on cotton establishment and lint yield. It was hypothesised that the use of thin oxodegradable plastic film would increase soil temperature and conserve seedbed water possibly reducing the risk in early planting, while not reducing lint yield or fibre quality of cotton. Experiments were conducted near Narrabri, NSW Australia during the 2010, 2012-2014 and the 2012 and 2013 seasons near Griffith, a cooler region in southern NSW with three or four thin oxodegradable plastic films with different formulations and break down rates being compared with a bare soil treatment. Planting depth soil temperature and soil water potential was monitored at three hourly intervals. Soil temperatures were elevated by 2-4 degrees C under the film compared with the bare soil that resulted in earlier (2-4 days) emergence of cotton under the film compared with bare soil. Soil also remained wetter beneath the film. Two films began to degrade at the time when cotton seedlings emerged (10-20 days), resulting in greater seedling survival (2-7 vs 12 plants/m). Seedlings were unable to penetrate four films on emergence and did not survive. When these films were slit to allow seedling growth, survival depended on subsequent environmental conditions; whether overcast/sunny or cool/warm conditions occurred. Using film that had been slotted prior to being laid in the field also increased soil temperature and conserved seedbed water. This enhanced (50-80%) emergence and survival of emerged seedlings, and overcame the need to slit film in the field.