膜上灌对春小麦苗期增温效应的研究

通过对河西内陆灌区膜上灌春小麦苗期在不同宽度的地膜覆盖下土壤温度观测得出:裸地对照的地温比膜上灌处理的日平均地温低1.8℃;0.75m窄膜覆盖的地温比1.25m宽膜覆盖的日均地温低0.92℃.在8:00、14:00和18:00,膜上灌各处理在0～25cm内的地温高于裸地,并且1.25 m宽膜覆盖的高于0.75 m窄膜覆盖的地温.随着土层深度的递增,早上8:00土壤表层和25 cm处的土壤温度,裸地分别为1.9和5.0℃,膜上灌处理的分别为3.3和5.3℃;中午14:00,表层至20 cm处的升温较快,裸地变幅在14～1℃,膜上灌处理的变幅在15.6～2.1℃;据18:00的观测结果,10 cm以上较午间降低,裸地温度降低3.6℃,膜上灌处理地温降低4.0℃;10 cm以下较午间升高,膜上灌处理的平均地温比裸地高0.5℃.

A Study on Temperature-Increasing Effect on Spring Wheat under Hole Irrigation in the Seedling Period

The conclusion of soil temperature of spring wheat under hole irrigation with different plastic film width in the Inland Irrigation District of HeXi was gained: the average soil temperature of bare field was lower by 1.8℃than that of hole irrigation,the average soil temperature of plastic mulching 0.75 m was lower by 0.92℃ than that of 1.25 m.At 8:00,14:00 and 18:00,the soil temperature of hole irrigation was higher than that of bare filed in 0～25 cm soil layer and that of 1.25 m was higher than that of 0.75 m.With the increase of soil layer,the soil temperature at soil surface and 25 cm and bare field was 1.9℃ and 5.0℃ at 8:00 respectively.At the same time,it was 3.3℃and 5.3℃ of hole irrigation.At 14:00,the increasing of soil temperature was obvious: the variation of bare field was 14～1℃ and it was 15.6～2.1℃ of hole irrigation.According to the result of 18:00,the temperature above the soil layer of 10 cm,was lower than that at 14:00 the temperature of bare field and hole irrigation descended 3.6℃ and 4.0℃ respectively.Soil temperature under the soil layer of 10 cm was higher than that of 14:00,and the average soil temperature of hole irrigation was higher by 0.5℃ than that of bare field.