Abstract: To explore new high-efficient water-saving irrigation methods in arid areas, field experiment was carried out to investigate the effects of alternate furrow irrigation in partial root zone on growth, yield and water use efficiency of cotton (Gossypium hirsutum L.) in an oasis region of Shiyang River Basin, Gansu province in 2004–2006. Planting with mulching and in furrows was applied with three partial root zone irrigation methods, i.e. conventional furrow irrigation (CFI, all furrows watered), fixed furrow irrigation (FFI, fixed one of every two furrows watered), and alternate furrow irrigation (AFI, neighboring two furrows alternatively watered) under three irrigation levels (225, 300, 450 m³ ha^-1 in 2004; 225, 300, 375 m³ ha^-1 in 2005; and 240, 360, 480 m³ ha^-1 in 2006) for each method in the three years. The results indicated that AFI shortened the cotton plant height, had no significant effect on reproductive growth such as bud and boll, and maintained the balance between vegetative and reproductive growth with reducing redundant growth. It regulated the distribution of photosynthesis products and ratio between root and shoot. AFI reduced ‘luxury’ transpiration without much reduction in photosynthetic rate, resulting in higher water use efficiency. In the three years, AFI always achieved the highest seed cotton yield under the three irrigation levels. Higher yield and reduced water loss also resulted in a higher water use efficiency (WUE) for the AFI treatment. Furthermore, percentage of pre-frost seed cotton yield under AFI was higher which meant better lint quality. Seed cotton WUE was improved by 17.22% and 18.59% as compared with CFI and FFI at the same irrigation levels of 37.5 mm in 2005. The results suggest that AFI should be a useful water-saving irrigation method in the arid region where cotton production is heavily dependent on irrigation.

Key words: Alternate furrow irrigation, Cotton (Gossypium hirsutum L.), Yield, Water use efficiency