水肥交互作用对黄土高原南瓜光合特性及其产量的影响

通过不同的灌水和施肥处理,研究水肥交互作用对南瓜光合特性日变化及产量的影响,结果表明：水分与施肥因子对南瓜叶片的光合特性和产量有重要影响,在水分胁迫的情况下,肥水交互作用不显著,在水分较低的情况下,二者表现互为限制条件的协同作用;在水分较高的情况下,肥水交互作用转变成顺序加和作用。其中单因素效应大小表现为：氮〉水〉磷,耦合效应大小表现为：氮与水耦合〉氮与磷耦合〉磷与水耦合。在水分适宜时,适宜的施肥量（施氮量50kg/hm^2、施磷量35 kg/hm^2）可以提高南瓜光合速率和产量,不施肥或施肥量过高都会影响南瓜光合速率和产量。

Influence of Water and Fertilizer Coupling on Photosynthetic Characters and Yield of Pumpkin In Loess Plateau

Effects of water and fertilizer coupling on photosynthetic characteristics and yield of pumpkin were investigated at conditions with different water and fertilizer treatments. The results showed that: the influence of water and fertilizer factors on the pumpkin photosynthetic characters and yield are great, water and fertilizer coupling was not significant under the water stress situation, water and fertilizer coupling was restricted eath other under the low water situation, water and fertilizer coupling was increased eath other under the high water situation. The ingle factor effect is: N>water>P, the coupling effect is: nitrogen and water coupling>nitrogen and phosphorus coupling>phophorus and water coupling. The appropriate fertilization level (nitrogen 50kg.hm-2, phosphorus 35 kg.hm-2) can increase the photosynthetic rate and yield of pumpkin when the water level was appropriated.