中文摘要：

采用旱棚盆栽试验,以郑单958为材料设置3个水分水平（正常水分W3、轻度水分胁迫W2、重度水分胁迫W1）和高氮N3（施纯氮315 kg hm–2）、中氮N2（施纯氮210 kg hm–2）、低氮N1（施纯氮105 kg hm–2）、不施氮N0四个控释尿素施氮水平,探讨控释尿素水氮耦合对夏玉米产量和光合特性的影响。结果表明,控释尿素水氮耦合对夏玉米产量和光合特性具有显著影响。相同水分条件下,夏玉米产量随施氮量增加而增加,W1条件下增产13.17%~20.96%,W2条件下增产13.93%~32.48%,W3条件下增产14.37%~21.83%。相同施氮水平下,产量也随水分增加而增加,W2N3、W3N2和W3N3的产量在所有处理中较高。水氮耦合对夏玉米穗位叶净光合速率的影响显著,W1条件下N3、N2和N1处理间差异不显著,均显著高于N0,W2、W3各施氮处理的净光合速率随施氮量增加而增加,W3各处理的平均净光合速率高于其他2个水分处理,W2N3比W3N3和W3N2前期略低,后期无显著差异。水氮耦合效应能有效减缓穗位叶的实际光化学效率ΦPSII、叶片光化学猝灭系数qP以及PSII反应中心的最大光能转换效率的下降速率,提高光能利用率。控释尿素水氮耦合能有效提高夏玉米花后穗位叶净光合速率,保证籽粒对营养物质的需求,提高穗位叶实际和最大光化学效率,从而提高夏玉米的产量,产量构成因素中增加千粒重和穗粒数的优势较大。综合产量与光合特性、荧光特性的表现,在田间持水量为75%±5%的土壤条件下,控释尿素施氮量以纯氮210 kg hm–2为最佳;在田间持水量为55%±5%的土壤条件下,控释尿素施氮量以纯氮315 kg hm–2为宜。

英文摘要：

A experiment using Zhengdan 958 （a summer maize eultivar planted widely in China）, with treatments of three water levels （normal water W3, mild water stress W2, severe water stress W1） and four amounts of controlled release urea nitrogen （N） （N3 was 315 kg ha-l, N2 was 210 kg ha^-1, NI was 105 kg ha^-1 and NO was no nitrogen） was carried out under the waterproof shed and potting conditions. The results showed there was significant influence of coupling water with controlled release urea on yield and photosynthetic characteristics in summer maize. Under the condition of same soil moisture, the yield showed a increasing trend with the amounts of N application increased. The yield increased by 13.17%-20.96% under severe water stress （W1）, by 13.93%-32.48% under mild water stress （W2）, and by 14.37%-21.83% under the condition of normal water （W3）. Under the same amounts of N application, the yield was also improved with the increase of the soil moisture. The yields of W2N3, W3N2, and W3N3 were the highest among these treatments. The coupling effects of water and controlled release urea were significant on the photosynthetic rate in ear leaf. The photosynthetic rates of N3, N2, and N1 had no significant differences in W1, and were higher than these of NO significantly. The photosynthetic rate of W2 and W3 treatments increased with the increase of N fertilizer application, the average photosynthetic rate in W3 was higher than that of W2 and Wl, that of W2N3 was slightly lower than that of W3N3 and W3N2 at early flowering, and no significant difference in the late stage. The coupling effects of water and con- trolled release urea nitrogen could effectively improve the efficiency of light energy utilization and slow down the decline rates of the actual photochemical efficiency of PSII, coefficient of photochemical quenching （qp） of leaf and PSII reaction center of light conversion. High photosynthetic rate, actual and maximal photochemical efficiency of ear leaf after flowering in summer m