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1.
为提高冬小麦花期长势遥感监测的精确性与普适性,在集丘陵地、河滩地及平原地为一体的冬小麦种植区域设计了田间试验,利用卫星影像信息结合地面GPS定点试验数据,在分析利用遥感技术监测冬小麦花期LAI和生物量两个主要群体长势指标可行的基础上,对卫星遥感光谱信息与冬小麦花期的主要生理生化指标(叶片叶绿素含量、叶片类胡萝卜素含量、叶片水分含量和叶片氮素含量)进行了综合分析.结果表明,NDVI(归一化植被指数)与LAI、叶片氮素含量和叶片水分含量的相关性较好,RVI(比值植被指数)与生物量和叶片类胡萝卜素含量的相关性较好,GVI(绿度植被指数)与叶片叶绿素含量的相关性较好,且均达到显著水平.说明NDVI、RVI及GVI是较为理想的可用于监测冬小麦花期生理形态指标的敏感遥感指数.进一步以这些敏感遥感指数作为因变量建立了冬小麦花期生理形态指标的遥感监测模型.利用本模型可以反演多个生理形态指标,便于对冬小麦花期的长势情况进行综合分析与判断.  相似文献   

2.
关中冬小麦叶片氮素含量高光谱遥感监测模型   总被引:2,自引:0,他引:2  
为给黄土高原大范围的冬小麦氮素营养遥感监测提供理论依据,通过田间试验,研究了冬小麦叶片氮素含量遥感监测的最佳生育时期、最敏感波段及其他最优光谱参量。结果表明,灌浆期是利用高光谱遥感监测冬小麦叶片氮素营养状况的最佳生育时期;在拔节、抽穗和灌浆期680nm波段光谱反射率R680均能较好地反映冬小麦叶片氮素含量,基于光谱位置以及叶面积指数的光谱参量也能较好地反映冬小麦叶片氮素含量。拔节期、抽穗期和灌浆期分别以680nm波段光谱反射率R680、绿峰反射率Rg和植被指数(SDr-SDb)/(SDr+SDb)对小麦叶片氮素含量的拟合效果最佳,其回归方程分别为Y=27.54-280.247 X+1456.245 X2、Y=8.632 X-0.24和Y=25.83 X1.012。  相似文献   

3.
基于GeoEye-1高分遥感影像的冬小麦氮肥推荐应用   总被引:1,自引:0,他引:1  
为给大区域范围的冬小麦氮素营养遥感诊断及其精准施肥决策提供参考,将GeoEye-1高分辨率遥感影像数据与氮肥优化算法(NFOA)相结合,开展了冬小麦氮肥推荐应用研究。首先,基于多年地面实测冬小麦冠层高光谱数据,利用光谱响应函数生成GeoEye-1卫星遥感模拟数据,计算得到归一化植被指数NDVI,并结合当季估产指数INSEY构建了冬小麦潜在产量预测模型;通过定义可表征小麦氮素丰缺的氮素响应指数RINDVI,结合潜在产量模型,计算得到氮素需求量;最后,利用GeoEye-1高分辨率遥感影像数据进行验证分析,将氮素推荐模型与高分辨率遥感数据相结合生成施肥推荐处方图,实现了冬小麦的氮素营养诊断及施肥推荐。结果表明,当季估产指数INSEY可很好地估算冬小麦的潜在产量(r2=0.606,RMSE=0.704t·hm-2),基于GeoEye-1高分遥感影像提取NDVI预测的潜在产量与实测产量显著相关(r2=0.722,RMSE=0.451t·hm-2)。氮素响应指数RINDVI与氮营养指数NNI的倒数也显著相关(r=0.915),可以用RINDVI来诊断冬小麦氮素的丰缺状态。以上结果说明,在没有地面实测小麦氮含量、生物量、地面光谱等数据的情况下,利用高分辨率遥感数据与气象数据构建模型可估算冬小麦的潜在产量,并能实现对冬小麦的氮营养诊断及生成推荐施肥处方。  相似文献   

4.
SPOT-5与HJ遥感影像用于冬小麦氮素监测的效果对比   总被引:2,自引:0,他引:2  
为探讨HJ遥感影像对冬小麦氮素监测的适用性,利用同期获取的SPOT-5和HJ-1B遥感影像,结合同步地面取样测试,从传感器的光谱响应、监测模型精度以及叶片氮含量空间填图3个方面,对冬小麦氮素的遥感影像监测效果进行了分析与评价.结果表明,两类遥感影像的3个波段反射率及植被指数与小麦叶片氮含量均密切相关,其中,SPOT-5影像的最优模型植被指数为GNDVI(绿色归一化植被指数),HJ-1B影像的最优模型植被指数为NDVI(归一化植被指数),SPOT-5影像在监测精度上优于HJ-1B影像,但差别不大.填图结果表明,除地块较破碎地带外,利用HJ-1B影像反演填图所得的小麦叶片氮含量在空间分布上与SPOT-5影像结果比较一致.说明利用SPOT-5与HJ遥感影像监测小麦氮素营养状况都是可行的,而HJ遥感影像在一定精度要求范围内能够替代SPOT-5等遥感影像的监测效果.  相似文献   

5.
为解决大田冬小麦叶片叶绿素含量估测模型精度低、通用性弱的问题,在获取冬小麦拔节期和抽穗期冠层红光波段反射率(BRred)和近红外波段反射率(BRnir)的基础上,计算归一化差值植被指数(NDVI)、差值植被指数(DVI)、比值植被指数(RVI)、土壤调节植被指数(SAVI)、改进型比值植被指数(MSR)、重归一化植被指数(RDVI)、II型增强植被指数(EVI2)和非线性植被指数(NLI)等8个植被指数。经统计分析,选择与叶片叶绿素含量(SPAD值)相关性较好的5个遥感光谱指标(NDVI、MSR、NLI、BRred和RVI)作为输入变量,建立了冬小麦叶片叶绿素含量的BP神经网络估测模型(WWLCCBP),并对估测模型进行精度验证。结果表明,WWLCCBP估测模型在拔节期估测的决定系数(r2)为0.84,均方根误差(RMSE)为5.39,平均相对误差(ARE)为9.87%。抽穗期的估测效果与拔节期较为一致。将WWLCCBP和高分六号影像...  相似文献   

6.
为进一步深化作物长势遥感监测机理与方法,给大田管理及时提供信息与技术,结合2011-2013年定点观测试验,以HJ-1A/1B数据为遥感影像源,研究了返青期冬小麦主要生长指标、籽粒品质参数和产量间及其与遥感变量间的定量关系,分别构建及评价基于HJ-1A/1B影像遥感变量的返青期叶面积指数、生物量、SPAD值和叶片含氮量监测模型。结果表明,返青期,归一化植被指数(NDVI)、比值植被指数(RVI)、蓝光波段反射率(B1)和RVI可分别作为监测冬小麦叶面积指数、生物量、SPAD和叶片含氮量的敏感遥感变量,所构建的遥感监测模型可靠且精度较高,模型的决定系数(R2)分别为0.62、0.56、0.46和0.58,均方根误差(RMSE)分别为0.42、452.3 kg·hm-2、4.39和0.54%。同时,对冬小麦不同等级主要生长指标进行遥感监测并制图,量化表达了主要生长指标区域空间分布。  相似文献   

7.
通过分析不同施氮水平下夏玉米叶片色素含量与冠层光谱反射率及其衍生的比值植被指数(RVI)、归一化植被指数(NDVI)、正交植被指数(MTVI2、MCARI2、SAVI、MSAVI)以及叶绿素吸收比值指数(CARI)之间的关系,建立夏玉米叶片叶绿素a(Chla)、叶绿素b(Chlb)、叶绿素a+b(Chl a+b)和类胡萝卜素(Car)含量估算模型。结果表明:NDVI与夏玉米叶片色素含量的相关性最好,RVI、RVI、CARI位居其次。通过逐步回归分析确立的夏玉米叶片Chla、Chlb、Chl a+b及Car含量的估算模型R2分别为0.790 8、0.832 4、0.808 8和0.761 7,说明利用冠层NDVI可以对夏玉米叶片Chla、Chlb、Chl a+b和Car含量进行可靠的监测。  相似文献   

8.
陆洲  罗明  谭昌伟  徐飞飞  梁爽  杨昕 《麦类作物学报》2020,40(10):1257-1264
为进一步探究利用中低分辨率影像监测小麦苗情的机理,丰富小麦长势动态监测的模式,结合2017-2018年定点观测试验,以GF-WFV数据为遥感影像源,研究了孕穗-开花期冬小麦主要长势变化量参数和产量及其与植被指数变化量间的定量关系,以逐步回归方法筛选目标长势变化量参数,分别构建及评价基于GF-WFV影像遥感植被指数变化量的孕穗-开花期叶片含氮量变化量和叶绿素含量变化量监测模型。结果表明,冬小麦叶片含氮量变化量(ΔLNC)和叶绿素含量变化量(ΔCHL)与产量密切相关,而孕穗-开花期的归一化植被指数变化量(ΔNDVI)、比值植被指数变化量(ΔRVI)分别与ΔLNC和ΔCHL相关性最好,因此选择这两个植被指数变化量作为敏感参量构建冬小麦长势监测模型。经验证,基于ΔNDVI和ΔRVI构建的长势线性模型可靠且精度高,其决定系数分别为0.70和0.64,均方根误差分别为0.39%和0.08 mg·L-1FW。基于预测模型和实测数据分级量化表达冬小麦长势的空间分布状况,能够很好实现了基于GF-WFV时相影像长势不同等级的遥感监测。  相似文献   

9.
夏玉米长势卫星遥感动态监测指标研究   总被引:1,自引:0,他引:1       下载免费PDF全文
李军玲  张弘  曹淑超 《玉米科学》2013,21(3):149-153
通过野外样点布设获取地面农学参数平均株高、群体密度、干物重和叶面积指数,经过频数统计分析,获得夏玉米一、二、三类苗苗情农学指标。结合MODIS遥感数据,进行农学参数和归一化植被指数(NDVI)的相关分析,结果显示,NDVI和平均株高、叶面积指数以及生物量都呈显著正相关,其中NDVI和叶面积指数关系最为显著(各生育期R2>0.623),因此可通过建立叶面积指数和NDVI的关系确定夏玉米长势遥感指标,为大面积遥感监测夏玉米长势提供科学依据。  相似文献   

10.
小麦花后15 d主要苗情参数多光谱卫星遥感定量监测   总被引:1,自引:0,他引:1  
为进一步探究小麦关键期苗情多光谱遥感监测机理与方法,提高多光谱遥感监测的定量化水平和可信度,结合两年定点观测试验,以环境减灾卫星HJ-CCD数据为多光谱遥感影像源,研究了小麦花后15 d主要苗情参数、籽粒品质参数和产量与多光谱卫星遥感变量间的定量关系,分别构建并评价基于HJ-CCD影像遥感变量的小麦花后15 d叶面积指数、生物量、SPAD和叶片含氮量的监测模型.结果表明,小麦花后15d时,结构加强色素植被指教(SIPI)、近红外波段光谱反射率(B4)、绿波段光谱反射率(B2)和归一化植被指数(NDVI)可分别作为监测小麦叶面积指数、生物量、SPAD值和叶片含氮量的敏感遥感变量,所构建的遥感监测模型可靠且精度较高,模型的决定系数(R2)分别为0.84、0.81、0.73和0.83,均方根误差(RMSE)分别为0.89、2 425.2 kg·hm-2、3.17和0.27%.同时,对小麦不同等级的主要苗情参数进行遥感监测并制图分析,量化表达了小麦主要苗情参数的区域空间分布.  相似文献   

11.
Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.  相似文献   

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14.
Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.  相似文献   

15.
Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.  相似文献   

16.
Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X1 (also called RXact).  相似文献   

17.
Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).  相似文献   

18.
The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.  相似文献   

19.
Summary Methods were developed for clean-up of potato tuber extracts on solid phase extraction CN-cartridges and for analysis of steroidal glycoalkaloids by reversed phase HPLC. The alkaloids α-solanine, α-chaconine, α-solasonine and α-solamargine could be separated on C8 or C18 reversed phase columns using a mobile phase of acetonitrile/Tris-buffer (3∶2, v/v). The analysis time of tuber extracts containing these alkaloids was less then 4 min, if the pH of the mobile phase was adjusted to 7.4 and run at a flow rate of 0.5 ml/min.  相似文献   

20.
Novel food and non-food uses for sorghum and millets   总被引:7,自引:3,他引:4  
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.  相似文献   

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