近30年我国棉花需水特征

利用1981—2010年我国棉花全生育期和各生育阶段降水资料,分析在不同年降水量保证率条件下,棉花全生育期降水和需水量的变化特征.结果表明: 我国棉花全生育期降水分布总体稳定少变,由南至北降水量递减;棉花全生育期需水量分布情况相似,新疆地区需水量较全国其他地方多;降水盈亏0毫米线在35° N附近,最大亏缺量在1000 mm左右,最大盈余量在800～1200 mm.各生育阶段需水量以下降趋势为主,尤其是开花-吐絮期更为明显,棉花全生育期需水量Kendall倾斜度为-3.6673～-0.3733.

Cotton water requirement character during recent 30 years in China.

Variation of precipitation in the whole growing period and water requirement of cotton under different levels of annual precipitation assurance from 1981 to 2010 were analyzed based on precipitation data during the whole growing period and each growing stage. The results indicated that the China’s precipitation distribution over the whole growing period, in general, was stable but decreased from south to north, and so was the distribution of water requirement, although it was higher in Xinjiang region. The precipitation deficit existed around the 35° N area, the maximum value was about 1000 mm, and the maximum surplus value was between 800 and 1200 mm. The water requirement declined during each growing stage, especially at flowering and boll opening stage, while the Kendall tendency varied from -3.6673 to -0.3733 in the whole growing period of cotton.