Abstract: Field experiments show that during the intergrowth period of cotton and wheat, the light intensity in crown layer of cotton seedling growing on the ridge of wheat field is about 30% of that in the same layer of mono planted cotton seedling, which is below the light compensation point in most time. Light is the most important factor affecting the development of interplanted summer cotton. The diurnal mean temperature at 0,5,10,15 and 20 cm soil depth in wheat field ridge is respectively 5.1,4.0,4.6,5.0 and 4.9℃ lower than that in mono planted cotton field, and respectively 2.1,1.8,1.1,0.6 and 0.6℃ higher than that in cotton row interplanted with wheat. Other environmental factors on wheat field ridge are generally superior than those on cotton row interplanted with wheat, but inferior to those on mono planted cotton field.The growing period of cotton comes earlier on wheat field ridge than on cotton row interplanted with wheat, but later than that of mono planted summer cotton, and the biological and economic characters of cotton are superior on wheat field ridge than on cotton row interplanted with wheat, but inferior to mono planted summer cotton.

Key words: Interplanting summer cotton, Ecological environment, Growth and development, dry farming regions, dual-mulching of ridges and furrows.