| The oasis region of Minqin County which is surrounded by Tengger Desert and Badain Jaran Desert is located in lower reaches of the Shiyang River Basin. Because of scarce rainfall and lack of surface water resources, agricultural production in the region mainly depend on the exploitation of underground water. In recent years, over-exploitation of underground water which was resulted by gradual decay of surface water resources from upper reaches resulted serious ecological problems in this region. Therefore, it is an effective way to find a practical water-saving irrigation techniques which was used to increase water use efficiency to solve these problems. Cotton is a main cash crop in this area, and the development of cotton planting in this area could raise the income level of local farmers.The main research objective of this paper is to explore the water-saving mechanism and application pattern of alternate furrow irrigation and alternative drip irrigation mulched with plastic film. In this paper, effects of APRI on cotton were studied with the analysis of soil water temporal and spatial variation, physiological response of cotton leaf, water use characteristic, yield, quality, soil heat condition and water use efficiency and economic benefits. The main results are:(1) In order to ensure irrigation water to be fully absorbed by crops and to prevent the deep leakage, the suitable irrigation amount per time is 240～480 m3hm-2. In the alternate drip irrigation mulched with plastic film, the frequency of irrigation should not be too high to ensure the effects of ADI more efficient.When the irrigation amount per time was set to be 180 m3hm-2, the proposed irrigation cycle is 7～14 d.(2)The data of Furrow Irrigation in 2 years showed that APRI could significantly reduce cotton plant height and leaf area index as well as increase boll load percentage. Overall it reduced the vegetative growth and increased reproductive growth. After the irrigation, the effects of stomatal regulation of APRI showed a gradually weakening trend. (3) The results showed that the soil temperature of wetted side in the treatment of AFI was lower than that of dry side during the alternate wetting and drying cycles, and the isothermal map of the ridge transection gradually became bilateral symmetry before the next circle of irrigation. The changes of volumetic soil water content of different furrows showed the same trend with soil temperature, which indicated that soil temperature has relationship with volumetic soil water content. The soil temperature of the ridge in the treatment of AFI was a little higher than that of CFI in the first circle of watering, and the differences between them had a tendency to increase during the second and third circle of irrigation.(4) The data of Furrow Irrigation in 2 years showed that when the irrigation amount of cotton was set to be about 50%of local border irrigation, AFI showed higher seed cotton yield and higher percentages of seed cotton yield pre-frost than in the treatment of CFI. As a result, the economic values of AFI were also higher than that of CFI. When the irrigation amount per time was set to be 180m3hm-2 , the treatments of ADI whose watering circle were 15d and 20d during the period of flowering and bolling have higher seed cotton yield and pre-frost yield as well as better fiber quality than CDI. With the increase of irrigation amount, the lengths of fibers have a tendency to increase. ADI can significantly improve cotton fiber length.(5) The ratio of soil temperature between different furrows has significantly linear relationship with ratio of volumetic soil water content between different furrows. As a result of analyses, a method which used soil temperature as an index to decide the suitable irrigation time of AFI was primarily introduced.
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