【摘要】 <正> 我国北方稻区太阳能资源十分丰富,日照百分率一般在50%以上,显著高于南方,而西北稻区达60—70%以上,居全国之首位。特别是水稻抽穗、灌浆期间,北方多为“天高云淡”的晴天,对后期干物质积累十分有利。北方水稻生育期间气候温和适宜,昼夜温差大,有利于降低呼吸强度、减少干物质消耗。大于10℃以上有效积温为2,200—5,100℃,基本满足一季早粳和双季麦茬稻对热量的需要。上述光、温气候因素,构成了北方稻作的优越环境,因此我国水稻高产纪录多出自北方的宁夏、新疆、辽宁以及江苏徐州等地。更多还原

【Abstract】 In the rice belt of North China the climate such as sunshine and the difference in temperatures between day and night is quite favourable for high yield of rice. Therefore, high yield records often come from this region. However,scanty rainfall and shortage of water resources limit rice cultivation. It seems that popularizing keng hybrid rice (japonica) and using both the irrigated and non-irrigated rice-planting methods may open a new prospect for rice culture in North China.Through investigation of rice production it has been found that keng hybrid rice has high yielding potential, wide adaptation and strong resistance to adversity. The hybrid rice has also proved to be highly effective in seed production and extremely profitable economically. All of these provide scientific basis for further expansion of hybrid rice in paddy field and irrigated upland field.The prospect for the exploitation of genetic potential of the hybrid rice is evaluated and discussed.更多还原