Duration of plastic mulch for potato growth under drip irrigation in an arid region of Northwest China

摘要

Field experiments were conducted to examine the effect the duration of plastic mulching has on soil temperature, evapotranspiration, potato (Solanum tuberosum L.) growth and yields, and water use efficiency (WUE), under drip irrigation in an arid region of Northwest China in 2006 and 2007. The duration of coverage with 0.0075mm thick, transparent plastic mulch on potato beds varied from zero days (i.e. no cover) to the entire season. The average daily air temperature during the two growing seasons was adequate for potato growth, but there were days when the maximum air temperature was above 30pC. Daily mean soil temperature under the plastic mulch was 2-9pC higher than for non-mulching conditions. The mulch effect on soil temperature was greatest during the early growth and became less as the plant canopy increased. Differences in the air and soil temperature between years could explain the difference of potato growth under different mulch durations for the two growing seasons. Mulch reduced irrigation water required and evapotranspiration; however, extending mulch duration beyond 60 days had little effect on evapotranspiration. Both tuber yield and WUE demonstrated benefiting from early plastic mulching. Mulch cover for 60 days was favorable for potato production in both years compared to potatoes grown without mulch.