棉花学报 Cotton Science 2006，18(1)：23～26
The Spatio-temporal Variability of Soil Available Nutrients of Cotton Fields in Xinjiang Abstract：A field experiment was conducted to study the spatio-temporal variability of the soil alkali-hydrolyzable nitrogen，available phosphorus and available potassium from the middle of February to the middle of November in oasis cotton fields(0～100 cm soil player) in south Xinjiang，which cotton lint yields was 1991 kg·hm-2.The results showed that the spatio-temporal variability of the soil alkali-hydrolyzable nitrogen and available potassium in 0～40 cm soil player were presented the similar trend，and that in 40～100 cm were not obviously changed. The contents of soil alkali-hydrolyzable nitrogen and available potassium in 0～40 cm soil layer were both increased gradually from the middle of February to the middle of June，attained the maximums between the middle of May and the middle of June，decreased dramatically from July to September，and then increased gradually from September. By contrast with June，alkalihydrolyzable nitrogen in 0～40 cm soil layer in July was decreased by 32.7～37.8 mg·kg-1. The contents of soil available phosphorus in plough-layer (0～20 cm) were not obviously changed during the whole experiment period，and the contents were between 27.1 mg·kg-1 and 34.3 mg·kg-1，and that of 20～60 cm were decreased dramatically from July to September，and reached the minimums at the middle of September. The contents of soil available phosphorus in 0～60 cm soil layer were increased gradually from April to July，attained the maximums at the middle of July，and that of 60～100 cm were always the lowest.
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