云南南亚热带地区气候资源与水稻、冬播玉米的适应性

Climate Resource and Adaptability of Rice and Winter-Sown Maize in Southern Subtropical Zone of Yunnan

云南南亚热带地区光能资源丰富 ,不仅表现在太阳辐射量高于我国华南和华东地区 ,而且辐射强度大 ,是籼型杂交水稻、冬播玉米等作物的高产区。全年热量资源充足 ,≥ 1 0℃积温在 6 0 0 0～ 75 0 0℃·d之间。但温度年较差小 ,日较差大 ,冬暖夏凉 ,一年四季都能种植玉米 ,是云南南亚热带地区玉米气候生态的一大特点。夏季高温强度不够 ,日照时数偏少是限制杂交水稻提高结实率和产量的主要因子。全年降水适中 ,但分布不均 ,地域差异大 ,干季降水量仅占全年总降水量的 1 0 %～ 1 5 % ,冬春干旱严重制约着冬播玉米以及水稻拔节前的生长发育。发展农田水利和灌溉是云南南亚热带地区夺取水稻、冬播玉米高产、稳产最重要的措施。

Yunnan Province has plenty of light resource in its southern subtropical zone where both hybrid rice and winter sown maize yield high.Besides,thermal condition is also very good with 6000 to 7500℃·d of ≥10℃ accumulative temperature for a whole year,smaller annual and greater diurnal temperature difference.Such climate as warm winter and cool summer can make maize be planted any time in a year,being typical of the southern subtropical climate zone for the crop.Not so high temperature in summer when sunshine is weak in some degree causes lower yield of the hybrid rice.Rainfall is distributed unevenly either in season or in space,though its annual total amount is proper,and within dry spring and winter seasons it is only 10% to 15% of the total,accordingly restricting growth of the winter sown maize and pre jointing rice.To develop water conservancy and irrigation therefore is the most important for achieving high and stable yields of rice and maize in this zone.