灌溉和施氮对甜叶菊(Stievia rebaudiana)光合作用和产量的影响

为了解水、氮供应水平对河西绿洲灌区甜叶菊(Stievia rebaudiana)光合作用和产量的调控效应,研究了灌溉量(常规灌溉,320mm;节水20%,灌溉256mm;节水40%,灌溉192mm)和施氮量(0、100、200、300kg·hm-2)对甜叶菊光合特性和产量的影响。结果表明:与不施氮相比,施氮可显著提高甜叶菊不同生育期光合速率和产量,施氮处理间光合速率和产量差异均不显著;灌溉量从192mm增加到320mm,甜叶菊产量随灌溉量的增加先增加后降低。施氮100、200、300kg·hm-2下甜叶菊产量分别较不施氮增产6.00%、9.17%、9.76%,256mm灌溉量和300kg·hm-2施氮量为甜叶菊高产的最优组合,产量达到4 177.50kg·hm-2。

Effects of Irrigation and Nitrogen Application on Photosynthetic Characteristics and Yield of Stevia rebaudiana

A field experiment was carried out to study the effects of irrigation quota (conventional, 320 mm; 20% water-saving, 256 mm; 40% water-saving, 192 mm) and nitrogen supply (0, 100, 200, 300 kg·hm^-2) on photosynthetic characteristics and yield of Stevia rebaudiana in the Hexi Oasis, Gansu, China. The results showed that the photosynthetic rate and yield of S. rebaudiana were all elevated remarkably by applying nitrogen fertilizer compared with 0 nitrogen fertilizer (CK), and the change of photosynthetic rate and yield of S. rebaudiana had no significant differences between treatments with applying nitrogen fertilizer. The irrigation anount increased from 192 mm to 320 mm, yield of stevia rebaudiana increased at first and then decreased with the increase of irrigation volume. Compared with nitrogen application level of 0 kg hm^-2, the S. rebaudiana yield of nitrogen application level of 100, 200 and 300 kg·hm^-2 increased by 6.00%、9.17% and 9.76%. The optimal combination was 20% water-saving irrigation and nitrogen application level of 300 kg·hm^-2, the yield of S. rebaudiana reached 4177.50 kg·hm^-2 under this combined treatment.