水肥耦合调控对水稻光合特性的影响

Effect of Water and Fertilizer Coupling on Photosynthetic Characteristic in Rice

为探究水肥耦合调控对水稻的光合特性的影响,本研究采用淹水灌溉、节水灌溉、干旱胁迫3个灌溉模式为主因子,正交施肥处理作为副因子(纯N:0、69、138 kg/hm^2;P_2O_5:0、33.6、67.2 kg/hm^2;K_2O:0、54、108 kg/hm^2),于分蘖期、抽穗期、成熟期测定叶绿素含量,于灌浆期测定剑叶光合参数。研究表明,同一灌溉模式,施肥对叶绿素含量、光合速率、气孔导度影响程度不同,且均显著高于对照(p<0.05),与施肥量呈正相关,N_2P_2K_0或N_2P_1K_1最大;水分补偿效应在肥料空白组最明显,同时肥料充足补加水分也能显著提高叶绿素含量、光合速率、气孔导度等光合参数。产量结果表明,产量随施肥量的增加而增加,节水灌溉下N_2P_2K_0和N_2P_1K_1产量最高。因此,干旱胁迫水稻光合作用最弱,节水灌溉和淹水灌溉光合作用强差异小,但节水灌溉较淹水灌溉耗水少,则最佳灌溉方式为节水灌溉、施肥组合为N_2P_1K_1。

The effects of water and fertilizer coupling on the photosynthetic characteristics of rice were studied by three irrigation models including flood irrigation, water-saving irrigation, and drought stress were the main factors, and an orthogonal fertilizer treatment was used as the secondary factor（pure N： 0 kg/hm2, 69 kg/hm2, 138 kg/hm2, P2O5： 0 kg/hm2, 33.6 kg/hm2, 67.2 kg/hm2 and K2O： 0 kg/hm2, 54 kg/hm2, 108 kg/hm2）. The chlorophyll content was measured at the tillering, heading and maturing stages. The photosynthetic parameters of the blade were measured at the filling stage. In the same irrigation model, chlorophyll content, photosynthetic rate, stomatal conductance and fertilizer application were positively correlated, and that of N2P2K0 or N2P1K1 was the largest, which was significantly higher than that of F-fertilizer control（p0.05）. The water compensation effect was most evident in the blank fertilizer group. Adequate supplementation of fertilizer significantly increased photosynthetic parameters such as chlorophyll content, net photosynthetic rate, and stomatal conductance. Therefore, photosynthesis of rice under drought stress was the weakest, and the difference in photosynthesis between water-saving irrigation and flood irrigation was small. However, water-saving irrigation had less water consumption than flood irrigation, and the best irrigation method was water-saving irrigation and fertilization combined with N2P1K1.