vegetation index Articles
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Determination of dry matter yield from legume–grass swards by field spectroscopy
An efficient and accurate detection of dry matter (DM) yield of legume–grass mixtures can facilitate a targeted and site-specific management of legume-based swards. The major objective of this study was to examine the relationship between spectral signatures of legume–grass swards and DM yield across a wide range of legume species (white clover [Trifolium repens L.], red clover [T. pratense L.], ...
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Inter-annual variability and interaction of remote-sensed vegetation indexand atmospheric precipitation in the Aral Sea region
The remotely sensed Normalized Difference Vegetation Index(AVHRR NDVI) and precipitation data were analysed in the Aral Sea region in Central Asia during two recent decades. Both variables exhibited pronounced seasonal variation, with maximum precipitation in March and maximum NDVI in May–June. The regions of synchronous seasonal and interannual variability between the vegetation indexand ...
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A simple spectral index using reflectance of 735 nm to assess nitrogen status of rice canopy
Spatial distribution of canopy N status is the primary information needed for precision management of N fertilizer. This study demonstrated the feasibility of a simple spectral index (SI) using the first derivative of canopy reflectance spectrum at 735 nm (dR/d|735) to assess N concentration of rice (Oryza sativa L.) plants, and then validated the applicability of a simplified imaging system ...
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Spatial analysis of early wheat canopy normalized difference vegetative index
Efficient use of real-time canopy sensors requires knowledge of the scale (resolution) of variation in the measured canopy property. Knowing the amount of needed optical data requires estimation of the optimal combination of physical sensor density (number of sensors along the applicator boom) and sensor output density (sensor readings per unit distance along the travel path). The objective of ...
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Regional-scale assessment of soil salinity in the Red river valley using multi-year MODIS EVI and NDVI
Received for publication April 15, 2009. The ability to inventory and map soil salinity at regional scales remains a significant challenge to scientists concerned with the salinization of agricultural soils throughout the world. Previous attempts to use satellite or aerial imagery to assess soil salinity have found limited success in part because of the inability of methods to isolate the effects ...
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EVI vs NDVI: What’s the difference?
The wine industry has been using aerial imaging to measure vine vigor for decades. It is becoming more and more common for vineyard managers to use vigor maps to support their decision making in the field. These maps most often use the Normalized Difference Vegetation Index (NDVI) to measure vine vigor. NDVI has been the standard in the wine industry since the Mondavi Project in 1992. NDVI is a ...
By VineView
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Active sensor reflectance measurements of corn nitrogen status and yield potential
Active sensor reflectance assessments of corn (Zea mays L.) canopy N status are advocated to direct variable N applications and improve N use efficiency (NUE). Our goals were to determine: (i) growth stage and (ii) sensor vegetation index with greatest sensitivity in assessing N status and grain yield. Variable crop N was generated by supplying N at different amounts and times in three field ...
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Assessing vegetation response to drought in the Laohahe catchment, North China
In order to better understand the relationship between vegetation vigour and moisture availability, a correlation analysis based on different vegetation types was conducted between time series of monthly Normalized Difference Vegetation Index (NDVI) and Palmer Drought Severity Index (PDSI) during the growing season from April to October within the Laohahe catchment. It was found that NDVI had ...
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Data with Drew: Vegetation Indices
The cameras we use on fixed wing and drone aircraft capture visual picture images (RGB), near infrared images (NIR), and thermal images. A formula is used to analyse the NIR data returned and provides Pollen Systems with two main metrics to measure plant vigor: NDVI (Normalized Difference Vegetation Index) and NDRE (Normalized Difference Red Edge). These vegetation indices are each unique ways to ...
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Assessment of pasture biomass with the normalized difference vegetation index from active ground-based sensors
Calculating forage availability is challenging for managers of grazing systems due to the spatial heterogeneity of swards. Remote sensing applications may help to overcome this problem through estimates of biomass made with reflectance data. The objectives of this study were to (i) estimate herbage mass using an active, on-the-go, ground-based, narrow band sensor to calculate the normalized ...
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Spatial mapping of complex turfgrass sites: site-specific management units and protocols
Site-specific management units (SSMUs), similar in soil, plant, and irrigation requirements, are foundational to efficient management in precision agriculture. This concept is applied to management of complex turfgrass sites to improve irrigation practices. An experimental mobile unit mapped two golf fairways' turfgrass (Paspalum vaginatum SW.; ‘Salam’) in Naples, FL in summer 2006 on a 2.5 m ...
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Peanut response to planting date and potential of canopy reflectance as an indicator of pod maturation
Determining when to dig peanut (Arachis hypogea L.) is complicated because of its indeterminate growth habit. Pod mesocarp color is often used an indicator of pod maturation. However, this process is time consuming and is usually based on a relatively small subsample of pods from peanut fields. Research was conducted during 2003–2005 to determine if reflectance of the peanut canopy, using ...
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Nondestructive measurement of grapevine leaf area by ground normalized difference vegetation index
Vine leaf area index has a great impact on berry quality. This study was conducted to determine whether vine leaf area index could be estimated, and mapped through normalized difference vegetation index (NDVI) ground-based measurements. The NDVI measurements were performed using a Greenseeker (N-Tech Industires, Ukiah, CA and Oklahoma State Univ., Stillwater), pointed sideways at the vertical ...
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Spatial analysis of early wheat canopy normalized difference vegetative index: determining appropriate observation scale
Efficient use of real-time canopy sensors requires knowledge of the scale (resolution) of variation in the measured canopy property. Knowing the amount of needed optical data requires estimation of the optimal combination of physical sensor density (number of sensors along the applicator boom) and sensor output density (sensor readings per unit distance along the travel path). The objective of ...
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Evaluating multiple indices from a canopy reflectance sensor to estimate corn n requirements
With the increasing cost of fertilizer N, there is a renewed emphasis on developing new technologies for quantifying in-season N requirements for corn (Zea mays L.). The objectives of this research are (i) to evaluate different vegetative indices derived from an active reflectance sensor in estimating in-season N requirements for corn, and (ii) to consider the influence of the N:Corn price ratio ...
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Developing Nitrogen fertilizer recommendations for corn using an active sensor
Producers often overapply N fertilizer to corn (Zea mays L.) because of the uncertainty in predicting the economic optimum nitrogen rate (EONR). Remote sensing represents a potential opportunity to reduce this uncertainty with an in-season assessment of crop N status. This study examines the relationship between EONR and reflectance from a ground-based sensor, and considers its potential for ...
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Normalized difference vegetation index and soil color-based management zones in irrigated maize
Spectral vegetation indices such as the normalized difference vegetation index (NDVI) have been shown to be useful for indirectly obtaining crop information such as photosynthetic efficiency, productivity potential, and potential yield. The objectives of this study were (i) to examine the relationships among NDVI determined early in the growing season, soil color-based management zones (SCMZ), ...
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Community forest management in Sikkim Himalaya towards sustainable development
Sikkim state is rich in biodiversity with a vibrant traditionally strong conservation ethics in place. This work aimed to understand the diverse systems of community forest management and their status with special reference to the nature of institutions governing them. As such, prolific and luxuriant state of the forests is perceptible through remote sensing data based on derivations of ...
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Corn and soybean mapping in the united states using modis time-series data sets
Monitoring and mapping of U.S. croplands has long been a primary goal of many users of earth observation satellite data. The advantages of using low spatial and high temporal resolution data are (i) increased ability to monitor the phenological change of crop plants, and (ii) the possibility of generating consistent large area crop cover maps. This study investigates the potential of 500-m MODIS ...
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Nitrogen recommendations for corn: An on-the-go sensor compared with current recommendation methods
Precision agriculture technologies provide the capability to spatially vary N fertilizer applied to corn (Zea mays L.), potentially improving N use efficiency. The focus of this study was to evaluate the potential of improving N recommendations based on crop canopy reflectance. Corn was grown at four field sites in each of 2 yr in Centre County, Pennsylvania. Preplant treatments included: zero ...
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