秸秆还田下不同水肥对玉米气孔形态特征及其分布格局的影响

Effects of Irrigation and Fertilization on the Morphological Traits and Distribution Pattern of Stomata of Maize Leaves Under Straw Returning

为确定黄淮海平原地区秸秆还田下玉米生长所需的最佳水肥量,通过布设秸秆还田下的大田水肥试验,探究了灌水量和施肥量对不同生育期玉米的气孔形态特征及其空间分布格局的影响。研究结果显示:(1)拔节期和灌浆期玉米远轴面的气孔密度均明显高于近轴面的气孔密度,表明玉米叶片的远轴面与近轴面对灌水量和施肥量的响应并不一致。(2)玉米拔节期气孔宽度、气孔面积和气孔形状指数均明显大于灌浆期,表明气孔形态特征在玉米不同生育期对水肥的响应存在明显差异,且玉米拔节期气孔对水肥的响应比灌浆期更敏感。(3)在玉米拔节期,灌水量750 m^(3)/hm^(2)和施肥量750 kg/hm^(2) (W_(750)F_(750))处理下玉米叶片的气孔分布最为规则,而灌浆期玉米气孔在灌水量750 m^(3)/hm^(2)和施肥量600 kg/hm^(2) (W_(750)F_(600))时呈现最规则的分布格局。结果表明,秸秆还田条件下,最优灌水量(750 m^(3)/hm^(2))和施肥量(600 kg/hm^(2))处理的玉米气孔形态特征及其空间分布格局最有利于提高其气体交换效率,从而增加黄淮海平原玉米叶片的净光合速率和粮食产量。

In order to determine the optimal amount of water fertilizer needed for maize growth under straw returning in Huang-Huai-Hai Plain,the effects of irrigation amount and fertilizer amount on stomatal morphology and spatial distribution pattern of maize in different growth stages were investigated through field water and fertilizer experiments under straw returning.The results showed that:(1)The stomatal density on the abaxial surface was significantly higher than that on the adaxial surface in both the jointing and filling stages,indicating that the responses of irrigation amount and fertilizer application amount were not consistent between the adaxial surface and the abaxial surface of maize leaves.(2)Stomatal pore area and stomatal shape index at the jointing stage were higher than those at the filling stage,indicating that the response of morphological traits of individual stoma to the irrigation and fertilization treatments was different between the jointing and filling stages,and stomatal morphology was more sensitive to water and fertilizer at jointing stage than at filling stage.(3)At jointing stage,the stomatal distribution of maize leaves was the most regular under 750 m^(3)/hm^(2) irrigation and 750 kg/hm^(2) fertilizer(W750F750).While at the grainfilling stage,The stomatal distribution pattern was the most regular with the irrigation amount of 750 m^(3)/hm^(2) and the fertilizer amount of 600 kg/hm^(2)(W750F600).The results indicated that the stomatal morphology and spatial distribution pattern of maize were most conducive to improving the gas exchange efficiency under the optimal irrigation amount(750 m^(3)/hm^(2))and fertilizer amount(600 kg/hm^(2)),thus increasing the net photosynthetic rate of maize leaves and grain yield in the Huang-Huai-Hai Plain.