Remote Sensing and Environmental Plant Physiology What is Remote Sensing? KRReddy@pss.msstate.edu Department of Plant and Soil Sciences Mississippi State University Mississippi State, MS Remote Sensing • Remote sensing is defined as the art and science of obtaining information about an object without in direct physical contact with the object. • It is a scientific technology that can be used to measure and monitor important biophysical characteristics and human activities on Earth. Remote Sensing Includes …. • Remote sensing often involves collection of diverse pieces of information or data for a particular site, field or a target. • The data is combined and interpreted to provide useful information concerning the site or the target. • Geographic Information Systems (GIS),Geographic Position Systems (GPS) and geo(spatial)-statistics are sometimes used to organize spatial data. Scientific Principles • Sunlight strikes the Earth’s surface and certain wavelengths are either absorbed, reflected or transmitted. • Various materials absorb sunlight over specific wavelength intervals resulting in absorption features in reflectance spectra. • The location and shape of these unique absorption features provide information on the chemical composition of materials. A-Energy source or Illumination B-Radiation and atmosphere C-Interaction with target D-Recording energy of target by sensor E-Transmission, reception & processing F-Interpretation & Analysis G-Application 1 Spectral Characteristics of the Vegetation • A healthy leaf intercepts incident radiant flux directly from the Sun or from diffuse skylight scatted on to the leaf. Spectral Characteristics of the Vegetation Energy Balance • Using the energy balance equation, we can keep track of what happens to all the incident energy. • The general equation for interaction of spectral radiant flux on and within the leaf is Incident radiant flux = reflectance + transmittance + absorbance Reflectance = Incident radiant flux - (Absorbance + Transmittance) Percent reflectance = (target / reference) * 100 Typical Reflectance, Transmittance and Absorption Characteristics of Big bluestem Leaf Peep through Spectrally Cotton Leaves and Spectral Images Typical reflectance spectrum of cotton leaf 0.7 Internal tissue strongly reflective, biomass content 0.6 Reflectance COTTON Moisture content of vegetation, contrast between vegetation types 0.5 Typical Leaf Spectrum and Atmospheric Water Absorption Bands 589 0.4 700 0.3 0.2 Chlorophyll 0.1 Phenolics 0 400 800 1200 1600 Wavelength (nm) 2000 2400 760 800 2 What causes the reflectance to change? Reflectance and leaf structure Absorption Spectra of Chlorophyll a, b Beta Carotene, and other pigments Incident radiation Reflected radiation WAX LAYER UPPER EPIDERMIS PALISADE LAYER CHLOROPLASTS MESOPHYLL CELLS SUB-STOMATAL CAVITY GUARD CELLS LOWER EPIDERMIS What can we measure? • Cellulose, Pigments (chlorophyll, carotenoids), lignin, nonstructural carbohydrates, protein, oil etc. • • Greenness per surface area Canopy coverage What can Remote Sensing Contribute? • • • • • Site-specific history for field Stand establishment Early detection of disease Presence of buried structures, tracks Phenology or Developmental stages (e.g., bloom) What can Remote Sensing Contribute? • • • • • • Topography for site-specific management Soil properties for site-specific management Plant properties to estimate insect populations for site-specific management Site-specific identification of water stress? Sites with late-season nutrient deficiency Site-specific identification and management of weeds. Remote Sensing Multi-spectral or Hyperspectral 3 What is Multispectral Imaging? What is Hyperspectral Imaging? • Collection of reflected, emitted, or backscattered energy from an object or area of interest in multiple bands (less than 10) or regions of the electromagnetic spectrum. • Collection of reflected, emitted, or backscattered energy from an object or area of interest in multiple bands (from 10 to hundreds) or regions of the electromagnetic spectrum with each channel covering a narrow and contiguous portion of the light spectrum. • Multispectral imaging allows the analyst to perform reflectance spectroscopy on few spatial elements of the image scene. • Hyperspectral imaging allows the analyst to perform reflectance spectroscopy on each spatial element of the image scene. Multispectral / Hyperspectral Comparison Hyperspectral Imaging - Rationale Principal objective is to identify and map specific vegetation, rock, and soil types. • Many disciplines require Alunite as seen by Multispectral and Hyperspectral systems quantitative results. systems under sample the spectrum. Landsat TM reflectance • Multispectral imaging AVIRIS • Identification of vegetation types, rock and soil types requires high-resolution spectra. 4 bands @ 80 m Landsat 4, 5 • Space-based Sensors (raw data) 7 bands @ 30 m SPOT GER 4 bands @ 20 m, Pan @ 10 m 63 bands @ 10 m AVIRIS 224 bands @ 20 m 1990 HYDICE 1998 PROBE-1 210 bands @ 1-3 m 128 bands @ 3 m 3 • Aerial-based Sensors (raw data) • Value-added reseller (processed data) Millions of Dollars 1,000 900 800 700 600 500 400 300 200 100 0 Space Aerial VAR VAR Landsat 1, 2, 3 AERIAL 1972 2 Global Remote Sensing Market SPACE Hyperspectral Remote Sensing is one part of an Inevitable Progression in Technology 1 wavelength (µm) Greater Spectral and Spatial Resolution 4 Sensors Remote Sensing Includes …. Ground-based • • • • • Satellite imagery Aerial photography Radar and Lidar Tractor-mounted sensors Hand-held instruments or sensors GER Radiometer -Typical Spectra GER ASD FieldSpec Space/ Aerial PHOTOGRAPHY Satellite RADAR, LIDAR CASI MEIS II ITD RDACS ASD FieldSpec Radiometer -Typical Spectra Well-watered and well-fertilized 0.7 0.6 CORN SORGHUM Reflectance 0.5 SOYBEAN COTTON 0.4 0.3 0.2 0.1 0 400 900 1400 1900 2400 2900 Wavelength (mm) Remote Sensing Examples: • High-resolution black-and-white or color photography. • Radar (RAdio Detection And Ranging, active microwave) and LIDAR (laser radar). Lidar is an acronym which stands for LIght Detection And Ranging. • Sonar (Transmission of sound waves through water column and then recording the energy backscattered from the bottom or from objects within the water column. High-Resolution Black-and-White Photography • Identification of landscape features 5 Remote Sensing – Radar and LIDAR High-Resolution Color Photography • Identification of landscape features • • • • • • Topography Tree height Canopy water content Vegetation type Biomass by component Canopy structure Remote Sensing – Images to Information Remote Sensing - LIDAR http://www.csc.noaa.gov/products/sccoasts/html/tutlid.htm Light Detection and Ranging (LIDAR) is a remote sensing system used to collect topographic data. This technology is being used by the National Oceanic and Atmospheric Administration (NOAA) and NASA scientists to document topographic changes along shorelines. These data are collected with aircraft-mounted lasers capable of recording elevation measurements at a rate of 2,000 to 5,000 pulses per second and have a vertical precision of 15 centimeters (6 inches). After a baseline data set has been created, follow-up flights can be used to detect shoreline changes. Spatial res olution Satellites • ADEOS • CORONA • COSMOS Sensors TOMS Optical X LOW M EDIUM HIGH VERY HIGH >2KM 2KM -100M 100M -10M <10M Radar X X TK-350 X X X KVR-1000 • EARTH PROBE • ENVISAT • ERS TOMS • JERS • LANDSAT • • • • • • • • • METEOR 3 METEOSAT NIMBUS 7 NOAA ORBVIEW2 RADARSAT RESURS-F RESURS 01 SPOT • SRTM X X X X AMI-SAR X ATSR X GOME • IKONOS • IRS-1C X X X X X X X X PAN X X LISS-III X WIFS X SAR X X TM X X RBV X X ETM+ X MSS X TOMS X X MSR X X X X SEAWIFS X SAR Large area Inventories X Regional Crop Mapping X X OPS AVHRR X X X X TOMS Remote Sensing – Agriculture In the beginning … X X X X X X X KFA-1000 X MSU-SK X HRV X X HRVIR X X X VGT X X X X X 6 Remote Sensing – Agriculture Today, We do Several Things Estimating Grain Yield of Maize Landsat-TM Data Mean grain yield measured for 22 fields in October 1995 = 9.36 t/ha Mean of corresponding satellite derived yield = 9.18 t/ha • Pest Management (Insects and weeds) • Irrigation Scheduling • Crop Growth Monitoring • Nutrient Management • Stress Detection • Invasive Species Detection • Natural Resource Management and Applications Estimating Grain Yield of Maize 5-7 7-8 8-9 9-9.5 9.5-10 t/ha t/ha t/ha t/ha t/ha Analyses of deviations: RMS-error=1.38t/ha R²=0.50 Estimating Crop Yield in Hungary Crop maps for the 6 counties in Hungary derived from multitemporal high-resolution satellite data (Landsat TM and IRS-1C LISS III.) from the early May-August period of 1997. Estimating Crop Yield in Hungary Winter wheat yields per county and Hungary Winter barley yields per county and Hungary COSH Central Statistical Office, Hungary Maize yields per county and Hungary Sunflower yields per county and Hungary FOMI RSC FOMI Remote sensing Center Winter wheat yield forecast for the 6 counties in Hungary using our developed Landsat/IRS + NOAA AVHRR model. 7 Remote Sensing and Biodiversity Typical Spectra - Species Differences Well-watered and well-fertilized Remote Sensing and Weed Species 25 Cocklebur 0.5 Sicklepod Ipomea Reflectance 0.4 Reflectance 0.75 Prickly Sida Sesbania 0.3 0.2 0.1 0.50 0.0 400 Corn Sorghum Cotton 0.25 Total Chlorophyll (µg cm-2) 0.6 1.00 20 15 10 5 0 900 1400 Wavelength (nm) 1900 2400 Ipomea Cocklebur Prickly Sida Sesbania Sicklepod Weed species Soybean 0.00 500 1000 1500 2000 2500 Wavelength, nm Interpretation and Analysis – Data Types Spectral Space Feature Space Band 2 Image Space Interpretation and Analysis – Interpretation Analog Digital Band 1 1. Image space: Display of data in relation to one another in a geometric or geographic sense, and provides a way to associate each pixel with a location on the ground. 2. Spectral space: High degree of spectral detail or response to the type of material on the ground (grass, trees, soil, water etc.). 3. Feature space: Provides pattern recognition. 1. 2. 3. 4. 5. 6. 7. Tone Shape Size Pattern Texture Shadow Association 1. Preprocessing 2. Image Enhancement 3. Image Transformation 4. Image Classification and Analysis 8 Interpretation and Analysis – Analysis Single Bands (Any given band) Simple Ratios (Band1/Band2) Indices (Band1-Band2)/(Band1+Band2) Fourier transformation Wavelet decomposition Principle Component Analysis Supervised Classification Unsupervised Classification Hyperspectral Technology Applications Statistical Packages SAS GENSTAT MATLAB Software Tools Arc View Arc Info IDRISI ENVI IMAGINE Agriculture Applications Agriculture and Forestry • Geology • Environmental • Marine and inland waters • Civil – vegetation type identification, assessment of vegetative stress, crop yield, resource monitoring – mapping of minerals and rock types for mineral and hydrocarbon exploration – detection of spills, baseline studies, land use planning – mapping of shoreline materials, bathymetry, water quality – Transportation corridors, city planning Forestry Applications 1. 2. 3. 4. 5. 6. Crop type classification Crop condition assessment Crop yield estimation Mapping of soil characteristics Mapping of soil management practices Compliance monitoring (farming practices) Geological Applications 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. • Surface deposit / bedrock mapping lithological mapping structural mapping sand and gravel (aggregate) exploration/ exploitation mineral exploration hydrocarbon exploration environmental geology geobotany baseline infrastructure sedimentation mapping and monitoring event mapping and monitoring geo-hazard mapping planetary mapping 1) Reconnaissance mapping: • forest cover type discrimination • agroforestry mapping 2) Commercial forestry: • clear cut mapping / regeneration assessment • burn delineation • infrastructure mapping / operations support • forest inventory • biomass estimation • species inventory 3) Environmental monitoring • deforestation (rainforest, mangrove colonies) • species inventory • watershed protection (riparian strips) • coastal protection (mangrove forests) • forest health and vigor Hydrology Applications 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. wetlands mapping and monitoring, soil moisture estimation, snow pack monitoring / delineation of extent, measuring snow thickness, determining snow-water equivalent, river and lake ice monitoring, flood mapping and monitoring, glacier dynamics monitoring (surges, ablation) river /delta change detection drainage basin mapping and watershed modeling irrigation canal leakage detection irrigation scheduling 9 Sea Ice Applications 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Land Use Applications 1. 2. 3. 4. 5. ice concentration ice type / age /motion iceberg detection and tracking surface topography tactical identification of leads: navigation: safe shipping routes/rescue ice condition (state of decay) historical ice and iceberg conditions and dynamics for planning purposes wildlife habitat pollution monitoring meteorological / global change research Mapping Applications 1.planimetry 2.digital elevation models (DEM's) 3.baseline thematic mapping / topographic mapping Need More Visit Remote sensing tutorial sites http://rst.gsfc.nasa.gov/ http://www.vtt.fi/aut/rs/virtual/ http://www.remotesensing.org/ http://www.research.umbc.edu/~tbenja1/ http://dynamo.ecn.purdue.edu/~biehl/MultiSpec http://www.cla.sc.edu/GEOG/rslab/images.html http://www.cla.sc.edu/geog/rslab/rsccnew/fmod1.html http://www.ccrs.nrcan.gc.ca/ccrs/eduref/tutorial/tutore.html http://www.agso.gov.au/education/remote_sensing/TOC.html 6. 7. 8. natural resource management wildlife habitat protection baseline mapping for GIS input urban expansion / encroachment routing and logistics planning for seismic / exploration / resource extraction activities damage delineation (tornadoes, flooding, volcanic, seismic, fire) legal boundaries for tax and property evaluation target detection - identification of landing strips, roads, clearings, bridges, land/water interface Ocean and Coastal Monitoring Applications •Oil spill • Ocean pattern identification: • mapping and predicting oil-spill extent • currents, regional circulation and drift patterns, shears • strategic support for oil spill • frontal zones, internal waves, emergency response decisions gravity waves, eddies, • identification of natural oil seepage upwelling zones, shallow water areas for exploration bathymetry •Shipping • Storm forecasting • navigation routing • wind and wave retrieval • traffic density studies • Fish stock and marine mammal • operational fisheries surveillance assessment • near-shore bathymetry mapping • water temperature monitoring •Intertidal zone • water quality • tidal and storm effects • ocean productivity, • delineation of the land /water interface phytoplankton concentration • mapping shoreline features / beach and drift dynamics • aquaculture inventory and • coastal vegetation mapping monitoring • human activity / impact Early Sensitive Indication of Particular Stresses Mild Intensity of stress Severe Development of Stress 10 Remote Sensing – Atmospheric Carbon Dioxide Remote Sensing environmental limitation of crop growth, development and yield 0.6 360 ppm CO2 720 ppm CO2 ¾ Atmospheric Carbon Dioxide ¾ Solar Radiation ¾ Temperature ¾ Water (indirect) ¾ Wind ¾ Nutrients (N, P, K) ¾ Ozone, UV-B etc., ¾ Growth Regulators Remote Sensing environmental limitation of crop growth, development and yield Reflectance 0.5 0.4 0.3 0.2 0.1 0 0 500 1000 1500 2000 2500 3000 Wavelength (nm) Crop Growth and Development - Environment Response to Temperature 4-week old cotton seedlings ¾ Atmospheric Carbon Dioxide ¾ Solar Radiation ¾ Temperature ¾ Water (indirect) ¾ Wind ¾ Nutrients (N, P, K) ¾ Ozone, UV-B etc., ¾ Growth Regulators Environment Factors Temperature: 20 25 30 35 40 Remote Sensing and Environment Thermal Imagery http://wwwghcc.msfc.nasa.gov/irgrp/lst_goes_UHEI.html ¾ Strongly Affects: -- Phenology -- Vegetative growth, LAI, LAD -- Fruit Growth and Retention -- Respiration -- Water-loss and Water-Use ¾ Moderately Affects: -- Photosynthesis on a canopy basis 11 Remote Sensing and Environment Thermal Imagery Relationships between NDVI and plant height, the number of nodes, LAI or biomass 1.0 0.9 0N 50 N 100 N 150 N NDVI 0.8 0.7 0.6 0.5 Y = 0.944(1-e 2 R = 0.99 0.4 -0.030x -0.057x ) Y = 1.48(1-e 2 R = 0.97 ) 0.3 0.2 0 20 40 60 80 100 0 5 0.8 0.7 NDVI 15 20 Col 10 vs Col 7 Col 10 vs Col 7 x column 2 vs y column 2 Col 14 vs Col 8 Col 18 vs Col 8 Col 22 vs Col 8 0.9 Thermal image of a cotton canopy that was part of a water and nitrogen study in Arizona. Blues and greens represent lower temperatures than yellow and orange. The image was acquired with a thermal scanner on board a helicopter. Most of the blue rectangles (plots) in the image correspond to high water treatments. 10 MSN (No. plant-1) Plant Height (cm) 1.0 0.6 0.5 0.296 0.4 Y = 0.231X0.215 2 R = 0.94 Y = 0.669X R2 = 0.97 0.3 0.2 0 1 2 3 0 Remote Sensing environmental limitation of crop growth, development and yield 200 400 600 800 Above Ground Biomass (g m-2) LAI Water Water plays essential roles in plants as a: ¾ Constituent ¾ Atmospheric Carbon Dioxide ¾ Solar Radiation ¾ Temperature ¾ Water (indirect) ¾ Wind ¾ Nutrients (N, P, K) ¾ Ozone, UV-B etc., ¾ Growth Regulators ¾ Solvent ¾ Reactant in various chemical processes ¾ Maintenance of turgidity The physiological importance of water is reflected in its ecological importance. The distribution plants over the earth’s surface is controlled by the availability of the water (amount and seasonal distribution of precipitation) where ever temperature permits growth. Environment Factors Water Deficits: ¾ Strongly affects: -- Vegetative growth, LAI, LAD -- Fruit Growth and Retention -- Water-loss and Water-Use -- Photosynthesis ¾ Moderately affects certain phenological events: -- Phenology (leaf development) 12 Environment - Water Role of water in cotton Sensitivity to water deficit Leaf GR LAI Stem GR Cell expansion Vegetative yield height Root GR Water deficit Mesophyll Resistance Canopy Rate of photosynthesis Photosynthesis Stomatal Resistance Rate of Transpiration Cell division & differentiation Rate of squaring Node production Seasonal transpiration bolls Economic shedding yield Boll GR Sequence of events Remote Sensing – Water Stress Plant water status Remote Sensing – Water Stress Indices to Define Water Status Plant water status is usually defined by measuring leaf water content Relative Leaf Water Content = (FW-DW)/(TW-DW) Relative Water Content = (FW-DW)/FW As it is the seat for the major plant events like photosynthesis, transpiration, respiration Relative Drought Index = WSDact / WSDcrit Leaf Water Content = FW-DW Irrigation is provided to crop plants to maintain the plant water status so as not to limit growth and development processes Equivalent Water Thickness = (FW-DW)/A (g cm-2) or cm Fuel Moisture Content = (FW-DW)/FW or DW Leaf water potential (ψW) = ψs + ψp + ψg 13 Leaf water potential – indicator of plant health Remote Sensing – Water Stress LWP is measured as negative pressure in bars or MPa. The LWP depends on - soil moisture (in the root zone) - resistance to move from root surface to water conducting vessels - resistance to flow through xylem - resistance from xylem to leaf cells - resistance to water loss from stomates depending on degree of opening Leaf water potential is measured using: - Psychrometer - Cryoscopic osmometer - Pressure probe - Pressure chamber Identifying the hyperspectral reflectance index Co-ordination of measurements ¾ Simple correlation analysis between leaf physiological parameters and spectral reflectance ¾ Linear regression analysis to determine the relation between leaf water potential and reflectance ratios LWPR = Xij / Xij where i and j indicate the reflectance values in a given spectrum and at a given leaf water potential 10:00:00 10:02:00 10:02:15 10:02:30 Photosynthesis Hyperspectral reflectance Fresh weight Leaf water potential LWPI = (Xij - Xij) / (Xij+ Xij) Diurnal trends of leaf water potential and transpiration rate in cotton Leaf water potential -0.5 -0.2 10 Leaf water potentail (MPa) 8 -0.6 -0.8 6 -1.0 4 -1.2 2 -1.4 -1.6 0:00 4:00 8:00 12:00 16:00 20:00 0 0:00 Transpiration rate (mm) -0.4 Leaf water potential (MPa) 12 0.0 y = -0.0017x - 0.0614 R2 = 0.9976 -1.0 y = -0.0036x + 0.7141 R2 = 0.9877 -1.5 -2.0 y = -0.003x + 0.1888 R2 = 0.9818 -2.5 -3.0 480 8 540 9 600 10 660 11 720 12 780 13 840 14 Time of day (h) Time of Day 14 Leaf water potential vs. Photosynthesis Hyperspectral reflectance spectra of 90 leaves 0.7 50 0.6 40 0.5 35 Reflectance Photosynthesis (µmol m-2 s-1) 45 30 25 20 P n = 39.29-0.097*0.7732 LW P R 2 = 0.78 P < 0.001 15 10 0.4 0.3 0.2 5 0.1 0 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 Leaf water potential (MPa) 0 500 1000 1500 2000 2500 3000 Wavelength (nm) Hyperspectral reflectance ratio vs. Leaf water potential Prediction of weekly measured data leaf water potential 0.0 -0.5 Predicted LWP (MPa) Reflectance Ratio (1689/1657) 1.00 0.99 0.99 y = 0.005x + 0.9954 R2 = 0.6636 0.98 -1.0 -1.5 -2.0 y = 0.9091x - 0.1827 R2 = 0.6263 -2.5 -3.0 0.98 -2.5 -2.0 -1.5 -1.0 -0.5 -3.5 -3.5 Leaf water potential (MPa) 34 Reflectance Predicted Pn (µmol m-2 s-1) -2.5 -2.0 -1.5 -1.0 -0.5 0.0 Observed LWP (MPa) Photosynthesis prediction using LWP and hyperspectral ratio y = 0.9272x + 2.0227 R2 = 0.6444 r = 0.80 32 -3.0 30 28 26 Indices reported in literature – Vegetative indices Reflectance Ratio WS Treatments R750/R650 -0.718 R935/R661 -0.736 R695/R760 0.609 R605/R760 0.54 (R750-R650)/(R750+R650) -0.713 (R935-R661)/(R935+R661) -0.728 (R850-R680)/(R850+R680) -0.727 (R900-R680)/(R900+R680) -0.728 (R790-R670)/(R790+R670) -0.739 (R531-R570)/(R531+R570) 0.835 (R550-R530)/(R550+r530) 0.449 R900/R970 -0.75 Time of day 24 24 26 28 30 32 34 LWP Predicted Pn (µmol m-2 s-1) 15 Remote Sensing environmental limitation of crop growth, development and yield Indices reported in literature – Water indices Reflectance Ratio WS Treatments Time of day R750/R550 0.901 R695/R420 -0.904 R710/R760 -0.906 R970/R900 -0.74 (R415-R435)/(R415+R435) 0.857 (R790-R720)/(R790-R720) 0.848 ¾ Atmospheric Carbon Dioxide ¾ Solar Radiation ¾ Temperature ¾ Water (indirect) ¾ Wind ¾ Nutrients (N, P, K) ¾ Ozone, UV-B etc., ¾ Growth Regulators R1450/R900 R970/R902 R790/R760 0.942 0.7 1689/1657 0.901 -0.928 Cotton and Nitrogen Physiology and Spectral Properties Photosynthesis - Variability Among Species Response to Leaf Nitrogen Photosynthesis, mg CO2 m-2 s -1 3 Maize Sorghum Cotton Sunflower 2 Rice Soybean 1 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Leaf Nitrogen, g m-2 Environment - Nitrogen Cotton Nitrogen •Cotton - Physiology Nitrogenand Experiment Spectral Properties •Physiology•Leaf andReflectance Spectral Properties 0.6 •0.6 Control •Control Nitrogen deficit •Nitrogen •-•Deficient 1.0 0.8 0.6 Reflectance •Reflectance Environmental Productivity Idices for Nitrogen 1.2 Stem Growth 0.4 •0.4 Photosynthesis 0.2 •0.2 Leaf Development 0.4 0.2 Leaf Growth 0.0 1.00 1.25 1.50 1.75 2.00 Leaf Nitrogen, g m-2 leaf area 2.25 0.0 •0.0 2.50 •500 500 •1000 1000 •1500 1500 •2000 2000 •2500 2500 •nm nm Wavelength, 16 Cotton Leaf N Concentration vs. R517/R413 Cotton Leaf Chlorophyll vs. Reflectance Ratios (Field N and Pix Studies) (Field N and Pix Studies) 2.5 2001 0.4 2001 2001 R551/R915 N study MC study 2.0 1.5 R517/R413 1.0 N study MC study 0.2 Y = -0.2784X + 2.0559 r2 = 0.69, n = 120 Y = -0.0176X + 1.9947 r2 = 0.78, n = 120 2002 0.3 Y = -0.0043X + 0.4549 Y = -0.00029X + 0.4821 2 2 r = 0.67 0.5 2002 2002 r = 0.83 0.1 2001 2002 0.6 R708/R915 2.0 1.5 1.0 0.5 0.4 Y = -0.3303X + 2.3375 r2 = 0.73, n = 156 Y = -0.0205X + 2.2225 r2 = 0.65, n = 156 0 10 20 30 40 50 60 1.0 3.0 0.2 20 4.0 2 r = 0.88 30 -2 Leaf N (g kg ) Y = -0.00045X + 0.7552 2 r = 0.76 2.0 -1 Y = -0.0077X + 0.7667 0.3 0.5 Leaf N (g m ) 40 50 350 500 650 800 950 Chlorophyll (mg m-2) SPAD reading n = 120 (5 times × 4 N treatments × 3 reps × 2 studies ) Correlation Coefficient ( r ) between Leaf Pigments, Leaf N Content, Phenolics, or Specific Leaf Weight (SLW) and Leaf Hyperspectral Reflectance. Corn Nitrogen Experiment Physiology and Spectral Properties 1.0 1.0 0.8 Correlation Coefficient (r) 0.6 1.0 0.8 Chl a Chl b Carot T.Chl 0.6 0.6 0.4 0.4 0.2 0.2 0.2 0.0 0.0 0.0 -0.2 -0.2 -0.2 -0.4 -0.4 -0.4 -0.6 -0.6 -0.6 -0.8 -0.8 0.4 -0.8 570 nm -1.0 300 720 nm Chl a/b Phenolic 0.8 Leaf N (%) Leaf N (mg/m2) Chl/Carot SLW -1.0 -1.0 700 1100 1500 1900 2300 2700 300 700 1100 1500 1900 2300 2700 300 700 1100 1500 1900 2300 2700 Wavelength (nm) Dotted lines represent significant levels at P = 0.05, n = 36) Relationship between Leaf N Content and Leaf Net Photosynthesis (Leaf N Was Expressed on Both a Dry Weight % and a Leaf Area Basis). Linear Regression of Leaf Pigment Concentrations with a Specific Reflectance Ratio •1.000 50 30 30 Y = 7.068X + 11.62 R2 = 0.551 Y = 21.601X + 8.448 R2 = 0.793 10 10 1.0 1.5 2.0 2.5 3.0 Leaf N (%) 3.5 4.0 0.4 0.6 0.8 1 1.2 Leaf N (g m-2) 1.4 1.6 • 0% N • 0% NL • 20% N •100% N •0.997 •0.996 •0.995 •0.9996 •0.9994 •0.9992 •y = -9E-05x + 0.9999 •2 •R • = 0.6128 •y = -0.0001x + 1.0001 •2 •R • = 0.5978 •0.994 •0.9990 •0 •10 •20 •30 •40 •50 •2 •1.000 •4 •6 •8 •0.9990 Carotenoids Total Chl. •0.999 •R756/R758 20 20 •0.998 •R764/R765 •R756/R758 40 0% NL Reflectance Ratio Leaf Pn (µmol m-2 s-1) 20% N 0% N Chl. b •0.9998 100% N 40 •1.0000 Chl. a •0.999 •0.9980 •R756/R759 50 •0.998 •0.997 •0.996 •0.9960 •y = -0.0007x + 1.0003 •2 •R • = 0.5347 •0.9950 •y = -8E-05x + 1.0001 •2 •R • = 0.639 •0.995 •0.9970 •0.9940 •10 •20 •30 •40 •50 •2 •4 •6 •8 Leaf Pigment Concentration (µg cm-2) 17 Linear Regression of Leaf N Content with a Specific Reflectance Ratio •0.80 •1.15 •1.05 •1.00 •0.95 Y = 0.0369X +0.8949 R2 = 0.750 •0.90 •0.0 •1.0 •2.0 •3.0 •4.0 •5.0 •6.0 •0.70 •0.60 •0.50 •0.40 Y = -0.2168X + 0.7437 R2 = 0.510 •0.30 •0.4 •0.6 •0.8 •1 •1.2 •1.4 Leaf N (%) •1.6 Leaf N (g m-2) Sorghum Leaf Chlorophyll or N vs. Reflectance Ratio (Pot Study) 0.5 1.4 R712/R1088 1.2 0.3 1.1 0.2 Y = 0.0003 X + 1.0124 r2 = 0.662 1.0 Y = 0.0047 X + 0.1591 r2 = 0.676 1.04 0.6 1.00 500 650 800 15 25 35 45 55 Leaf N (g kg-1) Crop N sensitive bands (nm) Algorithm† N r2 Reference Corn 555, 715 Chl = [(R712/R1088) – 0.845] ÷ (-0.00086) 36 0.59 Zhao et al., 2003a N = [(R575/R526) – 1.016] ÷ (-0.0017) 36 0.69 555, 710 555, 715 0.4 Chl = [(R708/R915) – 0.722] ÷ (-0.00040) 156 0.76 N = [(R517/R413) – 1.9947] ÷ (-0.0176) 120 0.78 Chl = [(R1075/R735) – 1.012] ÷ (0.00030) 21 0.66 N = [(R405/R715) – 0.159] ÷ (0.0047) 21 0.68 0.96 0.92 Y = -0.00086X + 0.845, r 2 = 0.59 Nitrogen, Physiology and Spectral Properties – Various Crops Sorghum 0.8 Y = -0.0017X + 1.016, r 2 = 0.687 0.0 Leaf chlorophyll (mg m-2) Cotton 1.08 0.2 0.1 350 1.0 0.4 R405/R715 R1075/R735 (B) (A) 100% N 20% N 0% N 1.3 0.9 200 Corn Leaf Chlorophyll or N vs. Reflectance Ratio (SPAR Study) R575/R526 R505/R645 R550/R1280 •100% N • 20% N • 0% N • 0% NL •1.10 † Chl Sorghum Nitrogen Experiment Physiology and Spectral Properties 0.88 0 100 200 300 400 Chlorophyll (mg m-2) 500 0 10 20 30 40 50 Leaf N (g kg-1) Nutrient Deficiency – Potassium Zhao et al., 2004b Zhao et al., 2004c = chlorophyll (mg m-2); N = leaf nitrogen (g kg-1); R = reflectance and subscript values are the wavelengths (nm). 18 Environment Factors Environment - Nutrients Potassium - Cotton Growth and Development Environmental Productivity Indices 1.6 Environmental Productivity Indices for Growth and Development Fertilizers Deficits - Potassium: ¾ Strongly Affects: -- Leaf growth, LAI, LAD -- Fruit Retention ¾ Moderately Affects: -- Photosynthesis -- Stem growth 1.4 Stem Elongation 1.2 Photosynthesis 1.0 0.8 0.6 Leaf Initiation Rates 0.4 Leaf Growth 0.2 0.0 -0.2 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Leaf Potassium, % Cotton Potassium Experiment Physiology and Spectral Properties Remote Sensing environmental limitation of crop growth, development and yield 70 60 Sufficient K Medium K Low K Reflectance, % 50 40 30 20 10 0 400 500 600 700 800 900 1000 ¾ Atmospheric Carbon Dioxide ¾ Solar Radiation ¾ Temperature ¾ Water (indirect) ¾ Wind ¾ Nutrients (N, P, K) ¾ Ozone, UV-B etc., ¾ Growth Regulators Wavelength, nm Atmospheric CO2 and UV Radiation Physiology and Spectral Properties UV-B Radiation Effect on Cotton Leaf Anatomy 19 Environment Factors UV-B Radiation – Phenology EPI Factors for various Developmental Processes 1.2 Ultraviolet-B Radiation: 1.0 ¾ Strongly Affects: -- Photosynthesis -- Stem growth UV-B index 0.8 Node addition 2 2 y = -0.0003x + 0.0014x + 0.9997 R = 0.4619 0.6 Leaf are a e xpansion 2 ¾ Moderately Affects: -- Leaf growth -- Leaf aging ¾ No Effects: -- Phenology 2 0.4 y = -0.0015x + 0.0102x + 0.9914 R = 0.8136 0.2 Ste m e longation 2 2 y = -0.0023x + 0.0105x + 0.9926 R = 0.9331 0.0 -4 0 4 8 12 16 20 UV-B treatments (kJ m-2 d-1) Hyperspectral Reflectances of Cotton Leaves Exposed to Different UV-B and CO 2 Treatments Breakdown of spectral reflectances of cotton leaves into specific waveband regions with known properties exposed to different UV-B and CO2 treatments 0.20 0.6 0.15 0 kJ 8 kJ 16 kJ 360 ppm 0.5 0.4 0.60 Chlorophyll reflectance 0.55 0.10 0.50 0.05 0.45 Internal tissue reflectance 0.3 Reflectance Reflectance 0.2 0.1 0 0 500 1000 1500 2000 2500 3000 0.6 0.5 0.00 500 525 550 575 600 625 650 675 700 0.40 750 0.35 0.20 0.30 0.15 850 950 1050 1150 1250 720 ppm 0.4 0.3 0.2 0.25 0.10 Leaf water reflectance 0.1 0 0 500 1000 1500 2000 2500 0.20 1550 3000 Wavelength(nm) 1600 1650 1700 1750 1800 1850 0.05 2000 2050 2100 2150 2200 2250 2300 2350 2400 Wavelength (nm) Deviation of Spectral Reflectances of Cotton Leaves Exposed to Different UV-B Treatments from Control at Squaring and Flowering Stages Reflectance deviation from control (0 kJ UVB) treatment 0.08 Remote Sensing environmental limitation of crop growth, development and yield 0.08 At squaring 0.06 At flowering 0.06 0.04 0.04 0.02 0.02 0.00 0 kJ UVB 8 kJ UVB 16 kJ UVB 0.00 -0.02 -0.02 0 kJ UVB -0.04 -0.04 8 kJ UVB -0.06 16 kJ UVB -0.08 -0.06 -0.08 400 900 1400 1900 2400 400 Wavelength (nm) 900 1400 1900 2400 ¾ Atmospheric Carbon Dioxide ¾ Solar Radiation ¾ Temperature ¾ Water (indirect) ¾ Wind ¾ Nutrients (N, P, K) ¾ Ozone, UV-B etc., ¾ Growth Regulators 20 Remote Sensing and Plant Growth Regulators Environment Factors Growth Regulators - Mepiquat Chloride (PIX): ¾ Moderately Affects: -- Leaf, stem and branch growth and LAI ¾ Slightly Affects: -- Photosynthesis Mepiquat Chloride (PIX) - Growth EPI Factors Mepiquat Chloride (PIX) and Cotton Growth and Remote Sensing 1.2 80 MC Application Rate (g a.i. ha-1) (A) 70 Leaf growth 0.8 Reflectance (%) 1.0 50 40 30 20 Photosynthesis 0.6 10 0 (B) 2 0.4 Stem growth 0.2 0.0 Reflectance Difference (%) PIX and EPI Indices 0 25 50 100 60 0 -2 -4 -6 -8 -10 0.00 0.01 0.02 0.03 -12 300 400 Mepiquat Chloride, mg g-1 dry weight Mepiquat Chloride (PIX) and Cotton Growth and Remote Sensing • As expected, application of MC decreased plant growth, increased leaf chlorophyll concentration, and decreased leaf reflectance. • Reflectance values at 420, 545, 810, and 935 nm separated MC-treated plants from untreated plants under favorable growth conditions, but we were unable to distinguish the different application rates of MC. • Forward stepwise regression and discriminant analysis suggested that changes in leaf reflectance from MC application were due to increased chlorophyll and nitrogen concentrations. 500 600 700 800 900 1000 Wavelength (nm) Remote Sensing environmental limitation of crop growth, development and yield ¾ Atmospheric Carbon Dioxide ¾ Solar Radiation ¾ Temperature ¾ Water (indirect) ¾ Wind ¾ Nutrients (N, P, K) ¾ Ozone, UV-B etc., ¾ Growth Regulators 21 Remote Sensing and Environment Thermal Imagery Remote Sensing – Atmospheric Carbon Dioxide 0.6 360 ppm CO2 720 ppm CO2 Reflectance 0.5 0.4 0.3 0.2 0.1 0 0 500 1000 1500 2000 2500 Wavelength (nm) 3000 Thermal image of a cotton canopy that was part of a water and nitrogen study in Arizona. Blues and greens represent lower temperatures than yellow and orange. The image was acquired with a thermal scanner on board a helicopter. Most of the blue rectangles (plots) in the image correspond to high water treatments. Nitrogen, Physiology and Spectral Properties – Various Crops Hyperspectral reflectance ratio vs. Leaf water potential Reflectance Ratio (1689/1657) 1.00 Crop N sensitive bands (nm) Algorithm† N r2 Reference Corn 555, 715 Chl = [(R712/R1088) – 0.845] ÷ (-0.00086) 36 0.59 Zhao et al., 2003a N = [(R575/R526) – 1.016] ÷ (-0.0017) 36 0.69 Cotton 555, 710 Chl = [(R708/R915) – 0.722] ÷ (-0.00040) 156 0.76 N = [(R517/R413) – 1.9947] ÷ (-0.0176) 120 0.78 Chl = [(R1075/R735) – 1.012] ÷ (0.00030) 21 0.66 N = [(R405/R715) – 0.159] ÷ (0.0047) 21 0.68 0.99 0.99 Sorghum 555, 715 y = 0.005x + 0.9954 R2 = 0.6636 Zhao et al., 2004b Zhao et al., 2004c 0.98 † Chl = chlorophyll (mg m-2); N = leaf nitrogen (g kg-1); R = reflectance and subscript values are the wavelengths (nm). 0.98 -2.5 -2.0 -1.5 -1.0 -0.5 Leaf water potential (MPa) Cotton Potassium Experiment Physiology and Spectral Properties Hyperspectral Reflectances of Cotton Leaves Exposed to Different UV-B and CO 2 Treatments 0.6 70 0.3 0.2 40 Reflectance Reflectance, % 0.4 Sufficient K Medium K Low K 50 0 kJ 8 kJ 16 kJ 360 ppm 0.5 60 30 20 10 0.1 0 0 500 1000 1500 2000 2500 3000 1000 1500 2000 2500 3000 0.6 0.5 720 ppm 0.4 0.3 0.2 0 0.1 0 400 500 600 700 800 Wavelength, nm 900 1000 0 500 Wavelength(nm) 22 Remote Sensing and Insect Infestation Genotype Study – Nematode Damage – MSU North Farm NDVI Jul 08, 2002 Genotype Study North Farm, MSU Aug 10, 2002 Aug 21, 2002 Can we identify insect pest damage? Field Study Environmental Factors, Crop Growth and Remote Sensing • Treatments • • • • N study treatments (0, 50, 100, and 150 lbs/A) PIX study treatment (0, 8, 16, and 32 oz./A) Irrigation study (Irrigated, Non-irrigated) Genotype study (38 genotypes) • Measurements • • • • • • Location and Field Map for 2001 Field Study (North Farm, MSU) Leaf and canopy hyperspectral reflectance (weekly) Growth analysis (Plant height, nodes, LAI, biomass) (5 times) Pigments and phenolics (weekly) Yield and yield components Photosynthesis Leaf mineral nutrient contents Questions We Try to Answer • Which index or ratio is the best to estimate cotton growth and yield? • Which growth stage is the best date to use the index in estimating cotton yield? Irrig. Plots Pix Plots Nitrogen Plots • Which function can be used to estimate crop physiology, growth and yield? The image was taken on July 17 (First Flower Stage) 23 Indices 6/25 7/3 7/24 7/31 8/15 8/22 NIR/R (R750/R650) 0.524 0.354 0.421 7/10 0.589 0.391 0.202 0.009 (R750/R550) 0.647 0.482 0.403 0.199 0.295 0.433 0.219 (R935/R661) 0.523 0.364 0.480 0.673 0.523 0.040 0.150 NDVI (R750 R650) 0.501 0.394 0.653 0.723 0.372 0.234 0.047 (R935 R661) 0.497 0.401 0.815 0.752 0.508 0.080 0.189 (R850 R680) 0.475 0.389 0.763 0.747 0.434 0.183 0.152 (R900 R680) 0.477 0.390 0.774 0.760 0.466 0.142 0.180 (R790 R670) 0.476 0.391 0.676 0.768 0.416 0.173 0.131 12 24 30 30 30 30 Sample size (n) 30 Relationship between NDVI at One Week Prior to First Flower and Seedcotton Yield in 2001 N D V I [(R 9 3 5 -R 6 6 1 )/(R 9 3 5 + R 6 6 1 )] Correlation Coefficient (R) of Seedcotton Yield with Several Published Indices 0.92 Irrigation Study PIX Study N Study 0.91 0.90 0.89 0.88 0.87 Y = 3.27×10-5X+0.763 R2 = 0.665 0.86 0.85 0.84 2500 3000 Planting date: 5/14; Squaring date: 6/24; First flower: 7/17 3500 4000 4500 Seedcotton Yield (kg ha-1) Relationship between NIR and Plant Height or the Number of Mainstem Nodes (n =96) Relationship between NIR or NDVI and Biomass (n =96) 25 9.0 8.0 8 8.0 7 7.0 4 3 2 Y = 2.379Ln(X) - 4.006 1 R = 0.63 0 2 R = 0.67 15 30 45 60 75 6 90 105 120 135 150 Plant Height (cm) 8 10 12 14 16 18 20 22 4.0 3.0 100 200 300 400 500 600 700 800 900 1000 20 15 10 Y =21.6(1-0.99X) R2 = 0.76 5 Mainstem Nodes (no. plant-1) 5.0 Y =6.62(1-0.98X) R2 = 0.69 0.0 25 Y = 0.331X + 1.197 6.0 1.0 30 3.0 0.0 0 Y = 17.1(1-0.99 ) R2 = 0.0.78 0 4.0 7.0 2.0 X 5.0 1.0 0 10 5 2.0 2 15 0 0 0 NDVI [(R935-R661)/R935+R661)] 5 6.0 NIR (R935/R661) 6 NIR (R750/R550) 9.0 NIR (R750/R650) 9 N IR (R 7 5 0 /R 5 5 0 ) N IR (R 7 5 0 /R 5 5 0 ) 20 100 200 300 400 500 600 700 800 900 1000 0.95 0.90 0.85 0.80 0.75 0.70 0.65 Y =0.9X/(12.34+X) R2 = 0.63 0.60 0.55 0.50 0 100 200 300 400 500 600 700 800 900 1000 100 200 300 400 500 600 700 800 900 1000 Biomass (g m-2, from 5-time harvest data) Relationship between NIR or NDVI and Leaf Area Index (n =150) 25 Relationship between NIR or NDVI and Leaf Area Index (n =96) 8 25 9.0 8.0 7 Y = -39.9+54.9(1-0.22X) R2 = 0.68 5 4 Y = -5.65+12.27(1-0.21X) R2 = 0.56 3 0 0 1 2 3 4 5 6 0 1 2 3 4 5 6 15 10 X Y = -50.0+71.0(1-0.23 ) R2 = 0.70 5 0 0.75 0.70 0.65 X Y = -0.359+1.25(1-0.156 ) R2 = 0.62 0.60 0.55 0 1 2 3 4 5 6 1 2 3 4 5 15 10 X Y = -1.4+25.5(1-0.51 ) R2 = 0.72 0 0 1 2 3 Leaf Area Index (from LAI-2000 instrument) 4 5 6 4.0 3.0 6 20 5 0.50 0 5.0 Y =2.11+5.11(1-0.47X) R2 = 0.74 0.0 25 0.80 6.0 1.0 30 0.85 7.0 2.0 Y = 0.17+18.79(1-0.51X) R2 = 0.0.73 0.90 NIR (R935/R661) NDVI [(R935-R661)/(R935+R661)] 20 10 0 0.95 25 15 5 2 30 NIR (R935/R661) 5 NIR (R750/R550) 10 6 0 NDVI [(R935-R661)/R935+R661)] 15 20 NIR (R750/R650) NIR (R750/R550) NIR (R750/R650) 20 1 2 3 4 5 6 0.95 0.90 0.85 0.80 0.75 0.70 0.65 Y = 0.59+0.32(1-0.0.44X) R2 = 0.67 0.60 0.55 0.50 0 1 2 3 4 5 6 0 1 2 3 4 5 6 Leaf Area Index (from 5-time harvest data) 24 Changes in Plant height, the number of mainstem nodes, leaf area index, and above ground biomass during cotton growth under field conditions in 2001. 80 60 40 20 0.90 10 5 0.85 0 -2 Above ground Biomass (g m ) 0 15 NDVI Mainstem Nodes (no. plant-1) 0N 50 N 100 N 150 N 100 Plant Height (cm) 0.95 20 120 4 Lead Area Index Changes in NDVI of different treatments during field cotton growth 3 2 1 0 20 40 60 80 800 0.80 600 0N 50 N 100 N 150 N 400 0.75 200 0 0.70 20 40 Days after Emergence 60 80 40 60 80 100 Days after Emergence Days after Emergence Relationships between NDVI and plant height, the number of nodes, LAI or biomass Relationships between NDVI and plant height, the number of nodes, LAI or biomass 1.0 120 0.6 0.5 Y = 0.944(1-e 2 R = 0.99 0.4 -0.030x -0.057x ) Y = 1.48(1-e 2 R = 0.97 ) 0.3 0.2 0 20 40 60 80 100 0 5 15 1.0 0.7 0.5 0.296 Y = 0.231X0.215 2 R = 0.94 Y = 0.669X R2 = 0.97 0.3 60 0N 50 N 100 N 150 N 40 600 0.6 0.4 80 1 2 LAI 3 0 200 400 16 2 Y = 6.12-1.29X+2.94X 2 R = 0.99 14 12 10 8 6 4 2 5 Y=e R2 = 0.95 4 400 200 0 600 800 Above Ground Biomass (g m-2) 0.2 2 Y = 2.35-1.22X+1.54X R2 = 0.99 3 2 1 0 0.2 0 18 7.25X Biomass (g m-2) 0.8 100 0 Col 10 vs Col 7 Col 10 vs Col 7 x column 2 vs y column 2 Col 14 vs Col 8 Col 18 vs Col 8 Col 22 vs Col 8 0.9 Y = 4.24-171X+266X2 2 R = 0.99 20 20 MSN (No. plant-1) Plant Height (cm) NDVI 10 20 Mainstem Nodes (No. plant-1) 0.7 Plant Height (cm) NDVI 140 0N 50 N 100 N 150 N 0.8 Leaf Area index 0.9 0.4 0.6 NDVI 0.8 1.0 -1 0.2 0.4 0.6 0.8 1.0 NDVI What’s Next? Remote Sensing (RS): Provide spatial variable data for crop health and yield, and soil conditions, and some predictive capabilities. Crop Simulation Models and Decision Support Systems(CSM-DSS): Provide predictive capabilities and verification of RS features. RS and CSM-DSS: Deliver site-specific input management or optimization. 25