| In the movable rainproof shelter, spring maize (Longyu 58) was planted to study the effects of two irrigation modes including full irrigation (F) and regulated deficit irrigation (D), and three plastic film mulching durations including mulching till jointing stage (A), mulching till tasseling stage (B) and mulching all stages (C), on soil temperature at depths of 5, 10 cm and 15 cm, respectively, as well as growing cycle, dry mass, evapotranspiration and water use efficiency. Results showed that the leading factors for soil temperature at different growing stage varied. The temperatures at 5 cm were quite variable. Effect of increased temperature by plastic film mulching was mainly in 0 to 10 cm soil layer. The biggest difference in growth cycles between treatments (DB and FC) was 8 days. During the whole growth period, compared with mulching over all stages, the decreased soil temperature caused by mulching till jointing stage and mulching till tasseling stage contributed to the accumulations of dry mass by 16.3 g·℃-1 and 60.2 g·℃-1 in 2012, respectively, and 18.4 g·℃-1 and 61.8 g·℃-1 in 2013, respectively. Under the same irrigation mode, evapotranspiration became decreased with the increase of plastic film mulching duration. The evapotranspiration levels under regulated deficit irrigation at three kinds of plastic film mulching durations (A, B, C) were reduced by 7.1%, 6.6% and 4.3%, respectively, in 2012 and 6.3%, 6.2% and 5.4%, respectively, in 2013. Regulated deficit irrigation and mulching till tasseling stage could obtain high water use efficiency. The increments between extreme values (DB and FA) in two years were 0.12 g·mm-1 and 0.13 g·mm-1, respectively. In conclusion, in consideration of soil temperature, growing cycle and water use efficiency, the treatment by regulated deficit irrigation and mulching till tasseling stage had possible effects in increasing yield and saving water. |