施氮量对高密度种植下寒地春玉米光合生理及产量的影响

Effect of Nitrogen Application Rate on Photosynthetic Physiological and Yield of Spring Maize in Cold Region under Conditions of High Density Planting

以东农253为试验材料,种植密度为90000株/hm2,设置了0-N(不施氮)、70-N(195kg/hm2)、100-N(279kg/hm2)、130-N(362kg/hm2)四个氮肥处理,来研究施氮量对高密度种植下寒地春玉米光合生理及产量的影响。结果表明:四个氮肥处理的SPAD值(叶绿素含量)及Fv/Fm(PSII最大光化学效率)呈倒"V"趋势变化,均在灌浆期达到最大值,100-N处理功能叶片的SPAD值在灌浆期显著高于其他处理;100-N处理下的玉米功能叶片显著高于其他处理,光抑制最弱。吐丝期100-N处理的LAI(叶面积指数)数值最大,显著高于其他处理。灌浆期后100-N处理群体LAD(光合势)高于其他氮肥处理,并且总LAD也以100-N处理最高;100-N处理后底层和穗位层透光率均为最小。结果表明在黑龙江地区超高密度种植条件下以施氮100-N(279kg/hm2)处理为最适宜,玉米功能叶片的光合参数最佳,产量最高。

The experiment was carried out in Harbin area. Dongnong 253, a high-yield variety, was chosen as experimental material and planting density was 90000 plants/hm^2. Four nitrogen treatments, O-N （no N）, 70-N （195kg/hm^2）, 100-N （279kg/hm^2） and 130-N （362kg/hm^2） were set up to study the effect of different nitrogen treatments on leaf photosynthetic physiology and corn yield under high density planting. SPAD values （chlorophyll content） and F,/Fm （PSII maximum photochemical efficiency） were showed an inverted ＂V＂ trends under four nitrogen treatments, reaching maximum values in the filling stage. Take 100-N treatment as an example, leaf SPAD value was significantly higher than other treatments in filling period and photo-inhibition was the weakest. LAI （leaf area index） reached maximum value in silking period under 100-N treatment, significantly higher than other treatments. ARer filling stage, LAD of 100-N treatment groups was higher than other nitrogen treatment, and the total LAD showed the same results. The value of layer transmittance was lowest under 100-N treatment. 100-N （279kg/hm^2） nitrogen treatment was the most suitable for maize leaf photosynthetic function and reaching the highest yield under 90000 plants/hm^2 high density planting in Heilongjiang Province.