基于光空间分布的棉花长势监测研究

发布时间：2018-04-30 15:02

本文选题：棉花 + 长势　；参考：《华中农业大学》2016年博士论文

【摘要】：掌握并发展能够快速、准确地监测作物长势技术,是及时采取合理的田间管理措施构建合理的群体结构及标准化的长势,最终获得高产优质高效的重要前提。作物冠层的光合有效辐射(Photosynthetically active radiation,PAR)与产量形成高度相关,同时PAR在作物冠层的空间分布情况直接影响了作物长势在不同时期的动态变化征。开展基于光空间分布的长势监测技术研究,对实现快速监测棉花长势,提升棉花生产轻简化栽培和机械化管理具有重要的现实意义和学术价值。因此,本研究于2014-2015年在中国农业科学院棉花研究所东场试验基地(36°06'N and 114°21'E)以转Bt基因常规抗虫棉鲁棉研28(SCRC28)为材料,设6个密度处理(15000、33000、51000、69000、87000、105000 plants/hm2)3个重复,以空间统计学方法为基础通过网格法取样和空间插值方法,分析了棉花冠层PAR截获率(Interception rate of PAR,Ir)的空间分布,及其与棉花生长发育的相关性,最终又探索了利用数字图像快速获取冠层Ir的方法。主要研究结果如下:(1)不同密度棉花冠层Ir在成铃初期、成铃中期和吐絮期的半变异函数表明,Ir具有良好的空间结构性和空间自相关性,随着生育进程的持续同一密度处理棉花冠层Ir的自相关范围几乎都增大。进一步分析三个生育期不同密度棉花冠层Ir在不同点、面、区域的分布结果表明,垂直方向上Ir随着高度的增加而呈下降趋势;水平方向上,在生育前期和后期越靠近行间Ir越小,越靠近棉株Ir越大。而在生育中期棉花冠层中下部的Ir在水平方向上的变化较小,特别是在高密度群体冠层内。(2)棉花冠层Ir与叶面积(Leaf area index,LAI)呈指数关系,在生育前期随着LAI的快速增加冠层Ir也快速增加,而当LAI增加到一定范围后冠层Ir缓慢增加最终维持在一定水平;现蕾至开花前,密度越小果枝发生速度越快,随着累计Ir增加速度的加快果枝的发生速度先增加后下降;开花后,整个生育期内光截获达到峰值前累计光截获所占的比例越大第一朵白花上果枝数(Nodes above first position white flowers,NAWF)为5时所需天数越短而霜前花率越多;冠层Ir越多群体干物重越重,然籽棉产量却未必高,这可能与生殖器官的脱落和棉铃的空间分布有关。(3)进一步分析不同密度棉花冠层内生殖器官在成铃初期、成铃中期和吐絮期的空间分布及其与冠层内Ir空间分布的相关性表明:随着种植密度的增加单株上生殖器官的数量减少,大量的生殖器官在成熟前发生了脱落,从下部果枝到上部果枝脱落发生的位置越来越靠近主茎,且种植密度越大同一等位果枝上脱落的位置离主茎越近;垂直方向上的冠层中部、下部的累计Ir和水平方向上冠层外围的累计Ir均与成铃概率呈极显著的负相关;垂直方向上冠层中部和水平方向上冠层内围的累计Ir与脱落概率的关系最为密切,都呈开口向上的二次抛物曲线。可见作物冠层Ir与棉花的长势密切相关。(4)两年间六个密度处理棉花冠层数字图像的红色(Red,R),绿色(Green,G),蓝色(Bule,B),光强度(Intensity,I和V),Y通道(Y channel,Y),I2通道(I2 channel,I2)和Q通道(Q channel,Q)颜色特征值在整个生育期都呈开口向上的二次抛物线,色调值(Hue,H和H2)则呈开口向下的二次曲线,饱和度(Saturation,S和S2)两年间整个生育期的变化趋势则居于两种曲线之间。两年间只有H和H2值的变化趋势与冠层Ir的变化趋势一致且各密度处理的模拟方程的R2均达到了0.8以上,可知除H和H2值外其他颜色特征受外界环境的影响较大。冠层Ir与各模型颜色特征的相关性结果表明H和H2值与冠层Ir高度线性相关,因此H和H2值可以用来量化棉花冠层的冠层Ir,且该结论也得到了验证。综上所述,冠层内Ir与棉花长势息息相关,可以用来监测棉花长势,而数字图像中的色调值可以快速获取冠层光截获,这将为实现方便、快速、准确监测作物长势提供了可靠的理论基础。
[Abstract]:To master and develop fast and accurate monitoring of crop growth technology is an important prerequisite for building a reasonable group structure and standardization in time, and finally obtaining high yield, high quality and high efficiency. The Photosynthetically active radiation (PAR) is highly related to the yield of crop canopy. At the same time, the spatial distribution of PAR in crop canopy has a direct impact on the dynamic change of crop growth in different periods. It is of great practical significance and academic value to carry out the research on the monitoring technology based on the spatial distribution of optical space. It is of great practical significance and academic value to realize the rapid monitoring of cotton growth, improve the cotton production and simplify the cultivation and mechanized management of cotton production. In this study, 2014-2015 years at the east field test base of the Chinese Academy of Agricultural Sciences Cotton Research Institute (36 06'N and 114 degree 21'E), the Bt gene conventional insect resistant cotton and cotton lougan 28 (SCRC28) was used as the material, and 6 density treatment (1500033000510006900087000105000 plants/hm2) was set up by 3 repetitions, and the grid method was taken as the basis of the spatial statistics method. The spatial distribution of PAR Intercepting Rate (Interception rate of PAR, Ir) in cotton canopy and its correlation with cotton growth and development were analyzed with spatial interpolation method. Finally, the method of fast obtaining canopy Ir by digital image was explored. The main results were as follows: (1) the cotton canopy Ir at the same density was in the early bell stage, the middle bell and the opening of the cotton. The semi variation function of the period showed that Ir had good spatial structure and spatial autocorrelation. With the continuous same density of the growth process, the autocorrelation of cotton canopy Ir increased almost all. Further analysis of the distribution of different density cotton canopy Ir at different points, surface and region showed that the vertical direction of Ir along the vertical direction of the three growth stages. In the horizontal direction, the smaller the Ir, the closer to the cotton plant Ir, the smaller the Ir in the middle and lower part of the cotton canopy, especially in the high density canopy. (2) the cotton corolla layer Ir and the leaf area (Leaf area index, LAI) are exponentially closed. In the early stage of birth, with the rapid increase of LAI, the canopy Ir also increased rapidly. When LAI increased to a certain extent, the canopy Ir slowly increased and finally maintained at a certain level. Before bud to flowering, the smaller the density, the faster the fruit branch was, the faster the growth rate of the fruit branch increased and then descended as the cumulative Ir increased. The greater the proportion of light interception in the period of harvest, the greater the proportion of light interception before the peak, the more the number of Nodes above first position white flowers, NAWF is 5, the more days the required days and the more flower rate before the frost; the more canopy Ir, the heavier the dry matter, but the yield of the seed cotton is not necessarily high, which may be associated with the abscission of the reproductive organs and the cotton bolls. Spatial distribution is related. (3) further analysis of the spatial distribution of the reproductive organs in the canopy of cotton with different density, the spatial distribution of the middle bell at the middle of the bell, and the correlation with the spatial distribution of Ir in the canopy show that the number of reproductive organs on the single plant decreases with the increase of planting density, and a large number of reproductive organs fall off before maturity. The location of the lower branches of the lower fruit branches to the upper branches is getting closer and closer to the main stem, and the greater the planting density is, the closer the location of the same allelic branch is to the main stem; the accumulative Ir in the central part of the vertical direction, the cumulative Ir and the horizontal direction on the periphery of the canopy, is negatively correlated with the probability of the bell, and the vertical direction is in the canopy. The cumulative Ir of the canopy inner circumference in the Department and the horizontal direction is most closely related to the falling probability, and the two parabolic curves of the opening upward are shown. The crop canopy Ir is closely related to the cotton growth. (4) six density treatments for cotton canopy digital images are red (Red, R), green (Green, G), blue (Bule, B), and light intensity (Intensity, I and V) for two years. ), the Y channel (Y channel, Y), the I2 channel (I2 channel, I2) and the Q channel (Q channel, Q) show the two parabola of the opening upwards during the whole growth period. The tone value is the two curve of the opening downward. The variation trend of the whole growth period in two years is between the two curves. Only the variation trend of H and H2 values was consistent with the variation trend of the canopy Ir and the R2 of the simulated equations of each density treatment reached more than 0.8. It was known that the other color characteristics except the H and H2 values were greatly influenced by the external environment. The correlation between the canopy Ir and the color characteristics of the models showed that H and H2 values were linearly related to the height of the canopy Ir, so H and H2 were found. The value can be used to quantify the canopy Ir of the cotton canopy, and the conclusion is also verified. To sum up, the Ir in the canopy is closely related to the cotton growth, and can be used to monitor the cotton growth, while the tone value in the digital image can quickly capture the canopy light interception. This will provide a reliable reason for the convenience, rapid and accurate monitoring of the crop growth. On the basis.

【学位授予单位】：华中农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S562

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