论文总字数：16548字

目 录

摘要 1

Abstract 2

1 引言 3

2 材料与方法 4

2.1 试验区概况 4

2.2 长宽法测量叶面积指数 4

2.2.1 长宽法测量方法 4

2.2.2 长宽法计算LAI 4

2.3 照片法测量叶面积指数 5

2.3.1 照片的收集 5

2.3.2 照片法测量LAI原理 5

2.3.3 采用Caneye软件处理照片步骤 6

2.4 玉米叶面积指数的模拟 6

3 结果与分析 7

3.1长宽法测定的玉米LAI 7

3.2 照片法测定的玉米LAI 7

3.2.1 自动模式下测定的玉米LAI 7

3.2.2 固定光圈模式下测定的玉米的LAI 8

3.3 总的LAI与长宽法LAI的比较与拟合 9

3.3.1 两种模式下总的LAI与长宽法LAI的比较 10

3.3.2 两种模式下总的LAI与长宽法LAI的拟合 10

3.4 长宽法玉米LAI的模拟 12

4 结论与建议 13

参考文献 14

致谢 17

玉米的叶面积指数测定及模拟

高马丹

, China

Abstract: Leaf area index (LAI) can provide structural quantitative information for the initial energy exchange description of the crown surface. It is the basis for the study of material circulation and energy metabolism, and it is also one of the main indicators for predicting the growth status of crops and forecasting yield. It is important to diagnose the status of crop growth. To explore the method of obtaining corn leaf area index, Caneye software was used to analyze corn canopy photos under different camera exposure patterns. The results were compared with the leaf area index of long-width method to evaluate the applicability of photometric method to determine leaf area index. The results show: (1)The LAI measured by the long-width method increased rapidly at the seedling and jointing stages with the day sequence. The LAI at the flowering stage, grain filling stage, and wax ripening stage maintained a balance, stabilized at 8.5 m²/m², and showed a slow decline in LAI during the mature period; (2)In the photo method, the LAI in the automatic mode and the LAI in the fixed aperture mode are basically the same as the LAI of the long-width method. The maximum LAI in the automatic mode is about 5.5 m²/m², and the maximum LAI in the fixed aperture mode is 5.8.About m²/m²; (3) Caneye software handles the camera's vertical tilt of 57° in automatic mode. After correcting it with the formula Y=1.33X 0.08X², a more accurate LAI can be obtained; (4)The cumulative effective accumulated temperature of corn growth period or the number of growing days of corn can be calculated by the daily average temperature. The piecewise function related to accumulated temperature or the segment function related to the days can be used to roughly estimate the LAI change of summer maize in Nanjing; (5)The LAI of maize can be obtained by using the formula Y=1.642 0.049T_d-0.825d, using both the effective accumulated temperature and the growing days as factors.

Key words: leaf area index (LAI); Caneye; length and width method; photo method

1 引言

玉米是农作物中主要的种植作物之一，我国的玉米生产水平还有很大的提高潜力。影响玉米产量的因素有很多，玉米的叶面积指数与种植密度、栽培措施、玉米品种、气象条件等对玉米的产量都有密切的关系，玉米的叶面积指数对玉米的产量的影响尤为显著^[1]。叶面积指数(leaf area index)又称为叶面积系数，是指单位地表面积上叶片总面积占地表面积的比例。即:叶面积指数=叶片总面积/地表面积^[2]。叶面积指数是农艺学中最常见的指标之一，是与生理过程相关的参数。植物的冠层覆盖和结构都与LAI有关，它们对作物与环境之间的相互作用有影响。叶面积指数是计算干物质累积最重要的生理参数，也是反应作物生长状况和进行产量预测的主要指标之一，对诊断作物生长状况具有重要意义^[3-6]。在一定的范围内，作物的产量随叶面积指数的增大而提高，当叶面积指数增加到一定的限度后，田间相互遮蔽，光照不足，光合效率下降，产量反而下降^[7]。研究玉米LAI的变化的影响可以帮助我们更好的了解玉米的生长状况和预测玉米的产量^[8]。因此准确的测定出玉米的LAI是对农业生产显得尤为重要，并且研究玉米叶面积指数动态变化模式有重要的应用价值。

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