水分胁迫对黄淮海夏玉米农业气候资源利用的影响——Ⅱ.水分胁迫对区域生产力影响

IMPACTS OF WATER STRESS ON AGROCLIMATIC RESOURCES OF SUMMER MAIZE IN HUANGHUAIHAI PLAIN OF CHINA: IMPACT ON REGIONAL PRODUCTIVITY

在玉米抽雄期进行了水分胁迫实验 ,利用Licor 1 88B和Licor 6 2 0 0便携式光合作用测定系统测定了水分胁迫对玉米光合作用的影响状况 ,在此基础上建立了冠层光合生产力计算公式。计算结果表明 :当叶面积指数为 5时 ,水肥适宜状况下黄淮海地区夏玉米日总光合量变化在 95g·m- 2 至 1 0 5g·m- 2 之间 ,最高值出现在河南和山东两省交界处 ;当土壤湿度下降至田间持水量的 4 0 %时 ,该地区冠层光合日总量平均降低 5 0 %左右 ;水分胁迫对不同地区冠层光合日总量存在不同的影响 ,在夏玉米抽雄期水分胁迫对山东省玉米冠层光合日总量影响最大 ,水分增产潜力最高 ,此时为夏玉米水分关键期 。

Water stress experiment was conducted during head sprouting of summer maize in Huanghauaihai Plain of China, and the effects of water stress on photosynthesis of summer maize were revealed with Licor-188B and Licor-6200 partable Photosynthesis Analysisors, then a numerical model for simulating diurnal variation of canopy photosynthesis was established. Using the model to simulate daily photosynthesis of canopy, the results indicated that: 1) Given that the LAI was 5 0, the daily photosynthesis of canopy changed from 95g·m -2 to 105g·m -2 in Huanghuaihai Region under condition with suitable water and fertilizer, and the highest value was found in area adjacent boundary of Henan Province and Shandong Province. 2) When soil moisture reduced to 40% of field capacity, the daily photosynthesis of canopy declined about 50% in the region. 3) Maxium influence on daily photosynthes of summer maize was in Shandong Province. When soil moisture reduce to 40% of soil capacity, irrigation is necessary in heading stage of summer maize.