基于暗通道先验和区间插值小波变换的图像去雾霾方法

针对在雾霾天气条件下采集到的图像质量退化,影响现代化农业精准作业的问题,该文提出一种基于暗通道先验理论和区间插值小波变换的图像去雾新方法。该文将暗通道先验模型和区间插值小波变换相结合,期望能有效滤除雾霾信息,恢复景物颜色特征,使图像更加清晰。结果表明:经过该方法处理后,图像整体较明亮,图像的对比度和清晰度都得到提高,达到滤除图像中雾霾的效果。主观上符合人眼的观察感受,图像的层次感突出,景物细节纹理也保持较好,彩色图像的色彩饱和度被很好地保持住,图像的失真度较低,逼近景物的真实颜色。去雾效果与暗通道先验算法对比,该文算法标准差数值在R通道平均提高25.44%;G通道平均提高27.90%;B通道平均提高26.24%。因此,采用该方法可以实现图像去雾,为进一步准确获取图像信息奠定基础,适应于现代精准农业的应用。     

苹果采摘机器人视觉系统的暗通道先验去雾方法

针对雾霾严重气候条件下苹果采摘机器人视觉定位困难的问题,提出一种把暗通道先验（dark channel prior,DCP）原理应用于苹果图像去雾的调参和改进方法。给出了一种获取大气光系数 A 的方法,首先把计算得到的暗通道图结果存入矩阵,求暗通道图中的前1/1000个最大元素所在位置,并存储在与暗通道矩阵相同大小的新矩阵中;根据新矩阵中的位置信息获得 R 通道矩阵相应位置的值,最后求取这些值的平均值作为 A 的取值。根据工程需要,该研究取去雾强度ω恒为1。通过与多尺度 Retinex（multiscale retinex,MSR）方法、自适应直方图均衡化（adaptive histogram equalization, AHE）等常规方法以及其他文献的暗通道去雾使用方法进行对比试验,结论是该文的方法能获得更好的主观视觉效果。在结果图像的对比度方面,该研究使用的方法能得到平均对比度64.04,与计算速度较快的直方图均衡化方法的35.46相比,提升了81%;R 通道对比度为68.525,与直方图均衡化方法得到的 R 通道对比度36.425相比提升了88%;该方法得到的图像直方图整体上呈现中间高两边低的形状特点,表明相对其他去雾方法,该文的方法能得到较好的去雾图像质量。时间复杂度方面,改进后的 DCP 方法计算640×480的图像耗时在33～37 ms 之间,基本能满足实时要求。分割定位精确度方面,该文方法的综合定位精度为94.8%,高于其他方法。试验证明使用该文方法能在去雾的效率和性能方面得到较好的平衡,是一种可以用于实际采摘作业的可行方法。     

双背景光自适应融合与透射图精准估计水下图像复原

针对水下图像普遍存在低对比度、低亮度和颜色失真,以及现有的水下图像复原方法恢复结果不自然、亮度不均和主体色调偏红等问题。该文提出了双背景光自适应融合与透射图精准估计水下图像方法。采用基于水下光衰减特性和背景光平坦性的双背景光自适应融合策略以提高估算的融合背景光准确度,通过新型水下暗通道先验、反向饱和图和三通道光谱衰减系数估算出更加精准的水下图像透射图,最后将估算出的融合背景光与精准透射图应用于水下成像模型得到复原后的水下图像。在广东罗非鱼良种场水产养殖数据集和水下图像增强基准数据集的试验结果表明：对比暗通道先验、最大强度先验、基于模糊和光吸收、蓝绿通道去雾、基于背景光统计模型和透射图优化5种水下图像复原方法,在主观恢复效果评价中,该文方法能有效纠正水下图像失真、亮度偏暗和主体色调偏红等问题;在7个客观评价指标中,该文方法在6个指标中取得最好值,其中全参考图像质量评价指标中的峰值信噪比、结构相似性、均方误差和视觉信息保真度等数值比次好水下图像复原方法分别提升了0.52%、2.1%、3.4%和0.86%;无参考图像质量评价指标中的自然图像质量评价指标和水下图像质量评价数值比次好水下图像复原方法分别提升了2.4%和7.4%。该文方法在解决传统水下图像复原方法中存在的亮度不均和颜色偏红等问题具有一定优势,可以为水下图像复原方法提供技术借鉴。     

基于对比度受限直方图均衡化的水下海参图像增强方法

针对水下图像受到水下复杂光照的影响导致图像对比度差的现象,采用对比度受限自适应直方图均衡化方法(contrast-limited adaptive histogram equalization,CLAHE)对水下海参图像进行增强处理,算法首先将原始图像分割成若干个子区域并且大小相同,再选取特定值对每个子区域的直方图进行截取,并将截取下的像素均匀分配到每个灰度级,最终得到限定对比度直方图。并通过研究算法中的相关参数,得到适用于水下海参图像增强的参数值,取得了更好的增强效果。通过评价函数均方差(mean squared error,MSE),峰值信噪比(peak signal to noise rate,PSNR)和信息熵(information entropy)对比CLAHE方法和其他一些方法,结果显示CLAHE算法在水下海参图像提高质量和保持图像细节方面表现出更好的性能,为以后水下机器人的识别定位提供了方便。     

基于优化SIFT算法的无人机遥感作物影像拼接

针对作物遥感影像因对比度低所导致的使用尺度不变特征变换算法(scale-invariant feature transform,SIFT)提取特征点数目少,拼接效果不理想的情况,提出了一种基于图像锐化的自适应修改采样步长的非极小值抑制拼接算法,该算法在图像预处理中引入锐化滤波器对平滑后的图像进行卷积,增强图像细节,增加特征点提取数目,同时通过基于尺度的自适应修改采样步长,使图像特征点分布更加均匀,根据低对比度作物遥感影像的成像特性,采用非极小值抑制,提高图像匹配效率。在查找匹配点的过程中,引入最优节点优先算法(best-bin-first,BBF)查找最近邻与次近邻,采用随机抽样一致算法(random sample consensus,RANSAC)优选特征点。通过试验验证,该文改进后的算法相比于标准SIFT算法,在处理低空作物遥感影像时,特征点提取数目平均增加77.5%,特征点匹配对数平均增加15对,对于标准SIFT算法无法匹配的低对比度作物遥感影像,提取到了8对以上的匹配点对,满足了拼接条件。该改进算法相对于标准SIFT算法更适于低对比度遥感影像的拼接。     

基于改进湍流模型和偏振成像技术的水下退化图像复原方法

为了满足工厂化水产养殖中过程控制的信息化要求,该文提出一种基于改进湍流模型结合偏振成像技术,具有较强鲁棒性的水下退化图像复原方法。考虑内外尺度对波结构函数影响,结合折射率谱,改进水下湍流退化模型以提高复原算法先验知识的完备性;基于改进的退化模型和水下前向散射光的偏振特性,利用偏振成像技术提取退化图像中的噪声特征;基于退化图像噪声特征,采用约束最小二乘滤波法进行退化图像复原;最后,对复原效果进行相应比较,结果表明在强湍流条件下本算法具有更为理想的复原效果。该研究可为复杂水流条件下水下退化图像复原方法研究提供参考。     

基于扫描滤波的农机具视觉导航基准线快速检测方法

针对基于机器视觉的自动导航系统现有导航线提取算法易受外界环境干扰和处理速度较慢等问题,该文提出一种基于图像扫描滤波的导航线提取方法。首先获取不同农作物的彩色图像,使用2G-R-B算法对彩色图片进行灰度化处理,得到作物行和土壤背景对比性良好的图片。使用Otsu方法对图像进行分割,得到二值化的图像后,再采用腐蚀-中值滤波-膨胀的滤波方法对图像进行去噪处理。然后使用该文提出的扫描滤波导航线提取算法,将图像分成左右两部分,使用等面积三角形对两部分分别进行扫描后,再对扫描的结果进行滤波,从而提取作物行,得到导航线。试验结果表明,采用该方法处理一幅640×320像素的图像只需要76ms,可满足农机具实时导航的要求;与传统导航线提取算法相比,该算法计算速度快,适应能力强。     

基于噪声类型及强度估计的狭叶锦鸡儿叶切片图像盲去噪

狭叶锦鸡儿叶切片显微图像在获取过程中不可避免的受到噪声污染,会对后续处理造成不良影响。针对现有噪声类型未知,去噪算法存在速度慢、效果不理想等问题,该文提出图像噪声类型估计-强度估计-去噪这一处理过程,实现对狭叶锦鸡儿叶切片显微图像降噪目的。首先采用平滑区直方图重构和拟合法确定噪声类型;然后在此基础上,应用基于图像块的SVD(singular valuable decomposition,SVD)域图像噪声强度估计法对噪声标准差进行估计;最后在确定噪声类型和强度基础上,采用几何均值滤波(geometric mean filtering,GMF)和三维块匹配滤波(block-matching and 3-D filtering,BM3D)对图像进行联合去噪。试验结果表明:该文噪声类型估计法估计出切片图像噪声类型为加性高斯噪声,高斯函数对随机选取的15幅狭叶锦鸡儿叶切片图像平滑区域直方图数据点拟合优度2R均值为0.996,平均均方根误差RMSE(root mean squared error,RMSE)为0.144 6;采用该文噪声强度估计法估计出的切片图像噪声标准差???[2.5,4.0],处理标准差较小噪声,该文算法处理精度、运行速度和稳定性等方面存在明显优势;GMF-BM3D算法在较好去除图像噪声同时,极大的保留了图像纹理、边缘和细节等信息,同时极大的提高了算法运行速度,处理后的图像BRISQUE(blind/referenceless image spatial quality evaluator,BRISQUE)值为10左右,相当于原图BRISQUE值的1/2左右。与传统BM3D算法相比,去噪效果相当,但耗时约相当于传统BM3D算法的1/9。与小波去噪算法(wavelet threshold,WT)算法相比,虽速度相对较慢,但去噪后图像BRISQUE值比使用WT法低4左右。因此,该算法较好实现了对狭叶锦鸡儿叶切片图像准确降噪,为其后续处理提供了可靠技术支持。     

基于杂交小波变换的农产品图像去噪算法

针对现有图像去噪方法去噪效果不明显、易丢失细节特征等缺陷,提出了一种基于杂交小波变换的农产品图像去噪算法。该方法综合了小波去噪能较好保留图像细节特征和Wiener滤波器可得到最优解的优势,分别以经小波变换、Wiener滤波处理后的图像作为杂交小波变换初始种群的父本和母本,并以最大类间方差作为适应度函数来评价个体的优劣,通过杂交和变异操作实现基因重组,提取出小波变换与Wiener滤波在图像去噪中的优势基因;经过有限次的杂交代数最终得到兼有父本和母本优势的子代图像。试验中用红枣和小麦图像对算法进行测试,去噪后红枣和小麦的图像峰值信噪比（PSNR）分别为178.44和183.24,好于邻域平均法（176.76和175.16）、中值滤波法（174.79和173.13）、维纳滤波（172.75和173.48）和高斯滤波（167.50和165.60）等常规去噪方法,并且在视觉效果上同时兼有噪声低和边缘清晰等优点,表明该方法用于农产品图像去噪是有效的、可行的。     

无人机航拍林业虫害图像分割复合梯度分水岭算法

针对林业信息监测方式实时性差、监测范围有限等问题,为更加实时、准确地对林业虫害信息进行监测并计算监测样地中虫害区域比例,该文在搭建面向林区虫害监测的多旋翼无人飞行器航拍监测系统基础上,提出了一种基于复合梯度分水岭算法的图像分割方法。该方法引入全局直方图均衡化消除了图像暗纹理的影响,并采用形态学混合开闭重构滤波完成了图像样本的去噪处理。计算灰度图像各像素点的复合梯度实现了非相关区域(道路及裸地)的提取,最终利用分水岭算法实现了监测图像虫害区域的分割提取。利用该文所提算法对8幅虫害侵蚀程度不同的监测图像进行分割,并与传统分水岭算法、K-means聚类算法进行对比试验。试验结果表明,该文算法虫害区域提取的平均相对误差率分别降低6.56%、3.17%,平均相对极限测量精度分别改善7.19%、2.41%,能够相对准确地将虫害区域从监测图像中分割出来,可为后续林业虫害监测与防护提供参考。     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

Enhanced establishment and growth of giant cardon cactus in an eroded field in the Sonoran Desert using native legume trees as nurse plants aided by plant growth-promoting microorganisms and compost

To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB; the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants, no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi, enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant. In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after 30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as compost or PGPB can either amplify the effect or else attenuate it.     

Karyotypic and genome size variation in Cajanus cajan (L.) Millsp. (pigeonpea) and some wild relatives

Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value.     

Effect of some fungicide seed treatments on the survival of Bradyrhizobium japonicum and on the nodulation and yield of soybean [Glycine max. (L) Merr.]

Several commercial fungicide seed treatments were evaluated for their possible effect on the survival of Bradyrhizobium japonicum on seeds and on the nodulation and yield of soybeans in a greenhouse and a field experiment. quinolate Pro (carbendazim and oxine copper), Vitavax 200FF (carboxin and thiram), and Monceren (pencycuron) had a small effect or no effect on the survival of B. japonicum and on the nodulation and yield of soybeans. They can thus be considered compatible with soybean seed inoculation. Germipro UFB (carbendazim and iprodione), Apron 35J (metalaxyl), and Tachigaren (hymexazol) decreased B. japonicum survival and the nodulation and yield of soybeans and thus cannot be considered compatible with soybean seed inoculation.     

Einfluss der düngungsmethoden auf die entwicklung von zuckerrübenkrankheiten

Während neunjähriger (1994-2002) Untersuchungen in der Versuchsanstalt Ba?cyny (Fahlerde, Fall-Gleyboden, ausgebildet aus leichtem Lehmboden) wurde der Befall mit Krankheiten an der Zuckerrübe in Abhängigkeit von der Düngungsmethode bewertet. Folgende Methoden wurden angewendet: A - Mineraldünger, B - Stalldung und Mineraldünger, C - Stroh-, Gründung und Mineraldünger, D - Kompostdünger und Biopräparate (ökologische Düngung). Auf den Objekten A, B, C wurden bei konstanter Phosphor-Kalium-Düngung die Stickstoffgaben von 0 bis 180 kg.ha^?1 differenziert. Auf dem ökologischen Objekt D ohne Mineraldünger wurden statt Stickstoff die Biopräparate P₅₀₀ und P₅₀₁ verabreicht. Der geringste Befall von Krankheiten wurde an der Zuckerrübe auf jenem Objekt festgestellt, das mit Kompost und den Biopräparaten gedüngt worden war. Im Rahmen der konventionellen Düngungsmethoden wurde allgemein die höchste Intensität der Krankheiten an der mit Stroh, Gründung und Mineraldünger gedüngten Zuckerrübe beobachtet. Ausnahmen von dieser Regel bildete das Vorkommen von echtem Mehltau und Keimlingsfäule. Auf den Objekten A, B, C nahm die Intensität der Krankheiten mit der Steigerung der Stickstoffgabe zu. Auch die auf Objekt D verabreichten Biopräparate stimulierten die Entwicklung der Krankheiten. The effect of various fertilization methods on the diseases of sugar beet was estimated on the basis of nine-year studies (1994-2002) conducted in the Experimental Production Farm in Ba?cyny on loess-based, sedimentary-gley, light-clay soil. The following fertilization methods were applied: A - mineral fertilization, B - mineral and manure fertilization, C - straw, green manure and mineral fertilization, D - ecological compost and biodynamic preparations fertilization. In the objects A, B and C fertilized with phosphorus and potassium, various doses of nitrogen ranging from 0 to 180 kg/ha^?1 were used. In the ecological object D, where mineral fertilization was not used, biodynamic preparations P₅₀₀ and P₅₀₁ were applied instead of nitrogen. The lowest ratio of the diseases of sugar beet was observed in the object fertilized with the compost and biodynamic preparations. In view of the conventional fertilization methods, generally the highest incidence of diseases was noted in the sugar beet fertilized with straw, green manure and mineral fertilizers. The exception was the occurrence of powdery mildew and the black leg. In objects A, B and C the incidence of the diseases increased with the increase in nitrogen doses. The applied biodynamical preparations in the object D stimulated the development of diseases too.     

Prospects for control of Pythium damping-off of lettuce with Trichoderma,Gliocladium and Enterobacter spp.

Summary Damping-off of lettuce (Lactuca sativa) caused by Pythium ultimum was studied in pots containing a non-sterile potting mix in the glasshouse. Fifty P. ultimum sporangia g^-1 compost reduced the plant stand to 15% and shoot dry weight to 18%, but this reduction was totally prevented by applying Trichoderma harzianum at 2×10⁵ viable propagules g^-1 potting mix. Gliocladium virens and Enterobacter cloacae also alleviated the damping-off. E. cloacae did not adversely affect the action of the fungal antagonists. The co-existence of the bacterial and fungal antagonists was revealed on the root surface and inner surface of the testa by scanning electron microscopy, indicating the compatibility of the biocontrol agents.     

细菌、真菌及植物氮营养信号研究进展

氮素吸收代谢是所有生物生命活动的核心部分,因此,各种生物对氮的吸收与同化过程都有精细的调节。这种调节依赖于生物对体内氮素状况信号及体外（生长介质中）氮素信号的感受。过去几十年中,在细菌、真菌中已经对氮素营养信号有了较好的研究,而植物中则相对缓慢,但也有了一定的认识。本文重点比较细菌、真菌及植物中氮信号系统的组成,以期为进一步认识植物中的氮信号接受与转导系统提供启示。     

Potential of wild species for genetic enhancement of some semi-arid food crops

Discovery and incorporation of genes from wild species provide means to sustain crop improvement, particularly when levels of resistance in the cultigens are low and virulent strains of pests and pathogens overcome the host plant resistance. The extent of utilization and the potential of the wild genepool for genetic enhancement were reviewed in five important food crops viz. sorghum, pearl millet, chickpea, pigeonpea and groundnut grown in the semi-arid tropics. Introgression from compatible wild germplasm in the primary gene pool resulted in transfer of new cytoplasmic male sterility systems in pearl millet and pigeonpea, development of high protein, cleistogamous flower and dwarf pigeonpea lines and foliar disease resistant groundnut cultivars. Utilization of wild species in secondary and tertiary gene pools has been generally limited due to sterility, restricted recombination or cross incompatibility. Nevertheless, these species are extremely important as they contain high levels of resistance to several important biotic and abiotic stresses. Several of them, like those belonging to the Parasorghum section and the rhizomatous Arachis species are sources of multiple resistances and hold great promise to sustain crop productivity.     

“绿色革命”以来大气CO2浓度升高对C3作物营养品质的影响

自20世纪60年代"绿色革命"以来,育种技术和农耕技术的发展促进了农作物产量的大幅提升,然而作物的营养品质出现下降趋势。在相似的遗传背景下,大气CO_2浓度升高会使单位体积农作物产品的营养元素含量下降,因此"绿色革命"至今,农作物产品的营养元素下降可能受大气CO_2浓度升高影响。通过植物生长箱模拟"绿色革命"初期和目前的大气CO_2浓度水平(310μmol/mol和400μmol/mol),针对主要C_3作物水稻、小麦和大豆,研究"绿色革命"以来大气CO_2浓度升高对其籽粒的C、N、Fe、Zn元素含量的影响,结果表明:CO_2浓度升高对3种作物籽粒的C元素含量几乎没有影响,变化幅度在±1.5%之间;籽粒的N、Fe、Zn元素含量普遍呈现下降趋势,但均未达到显著水平。