施肥对不同种植模式下春玉米光合特性的影响

Effects of Fertilization on Photosynthetic Characteristics of Spring Maize in Different Planting Patterns

建立了一种密度与单作相同的超大宽窄行种植模式。通过小区试验,研究了该模式下施肥对春玉米单株叶面积、净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)及光响应曲线的影响,比较了该模式与单作模式玉米光合特性的异同。结果表明,随着施肥量的增加,Pn、Gs、Ci和单株叶面积都有增加趋势。间作玉米与单作玉米相比,玉米的单株叶面积表现为间作在生育前期小于单作,但在灌浆期及以后的生育时期单作下降较快,表现出间作明显大于单作;玉米叶片Pn生育前期单作较高,但生育后期间作明显高于单作。叶片光响应曲线及其拟合结果也表明,间作前期的最大净光合速率和表观量子效率均小于单作,生育后期大于单作。本试验表明,超大宽窄行种植模式有助于玉米生育后期光合条件的改善。

A super wide-narrow maize//soybean planting pattern with the same maize planting density as that in monocuhure pattern was established. Effects of fertilization on leaf area, net photosynthetic rate （Pn）, stomatal con- ductance （ Gs ）, intercellular CO2 concentration （ Ci ） and light response curve of spring maize in this pattern were investigated, and the difference in photosynthetic characteristics between the two patterns were studied as well. The re- sults showed that,Pn, Gs, Ci and individual leaf area all increased with the addition of fertilizer amount. Compared with the monoculture pattern, the individual leaf area of maize in intercropping pattern was smaller during early growth stages but larger from the grain filling stage and later. The Pn values were higher at early growth stages in monoculture pattern and at later growth stages in intercropping pattern. Leaf light response curve and its fitting re- sults also showed that the maximum net photosynthetic rate and the apparent quantum efficiency of maize were lower at early growth stages but higher at later stages in intercropping pattern. These results suggested that the photosyn- thetic conditions of spring maize were improved at later growth stages in the intercropping pattern. This study would provide theoretical support for innovation of maize planting.