【摘 要】
：
一般来说,技术的改良促进了美国玉米产量的上升,但是其它几个因素也是应该考虑的。如提高大气中 CO_2是玉米增产的一个重要因素。在控制条件下提高 CO_2浓度时,有利于玉米增
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一般来说,技术的改良促进了美国玉米产量的上升,但是其它几个因素也是应该考虑的。如提高大气中 CO_2是玉米增产的一个重要因素。在控制条件下提高 CO_2浓度时,有利于玉米增强光合作用,同时水份利用率也增加了。另一个因素是气候的变化,然而,很难将它与技术的改变加以区别。本文试图根据玉米产量,对美国玉米带的气候和天气变异性的变
In general, technological improvements have contributed to the increase in US maize production, but several other factors should also be considered. Such as increasing atmospheric CO 2 is an important factor in increasing corn yield. Increasing CO 2 concentration under controlled conditions was beneficial to enhancing maize photosynthesis and water use efficiency. Another factor is climate change, however, it is difficult to distinguish it from technological changes. This article attempts to change the climate and weather variability of the US corn belt based on corn production
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