Precision Agriculture Class Notes PDF 2023

Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai Lecture No. 1: Precision Agriculture: Concepts and tec...

Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai Lecture No. 1: Precision Agriculture: Concepts and techniques Precision Agriculture: The precision agriculture is information and technology based agriculture, which identify, analyze and manage the variability of the in order to increases resource use efficiency, productivity and profitability. Synchronization It is also defined as the application of technologies and principles to manage spatial and temporal variability associated with all aspects of agricultural production. In other words, precision farming is the matching of resource application and agronomic practices with soil attributes and crop requirements as they vary across a field. The major aims of precision farming are: 1. Handling the variability in field at the narrowest level as possible. 2. Optimize the resource use efficiency. 3. Reduce the adverse effect of excessive use of agro-inputs on the ecosystem thereby reduce the foot print. 4. Productivity enhancement through precise and timely application of resources. 5. Enhance profitability through use of one resource. Component of precision farming: The basic and fundamental components of precision farming are information (data base), technology and management. These components are discussed under heads. 1. Data base: Under field conditions both soils and crops vary spatially and temporally. The information related to soil properties, crop characteristics, weed and insect population and harvest data are important to develop database necessary for realizing the potential of precision farming. Of these, entire crop yield monitoring is the most important component of precision farming technology and is the logical starting point for precision farming. It gives the farmer something to look at and start raising questions about his practices. Establishment of soil related characteristics within a field through regular soil sampling is another important database. In precision farming a decision has to be made on how to sample and how often to sample and what property to look for so that interpretation from database can be made with greater confidence. 2. Technology: The recent information technology and space technologies for monitoring yields and sensing soil related variables are new tools available to make precision farming a success. When measuring soil and crop characteristics, satellite based positioning system like Global Positioning System (GPS) can be used to identify the location where the data are taken. Organization of these data into usable form such as different layers of field maps, can be achieved through personal computer (PC) and Geographic Information System (GIS). Remote sensing techniques can also be utilized to detect soil related variables, pest incidence and water stress. The basic idea of precision farming is not only to measure the field variability, but also able to apply inputs at varying rates almost instantaneously in real time according to the needs. The variable rate application (VRA) machinery could be used to handle field application of inputs such as seed, fertilizers and pesticides at the desired location in the field at the right amount, at the right time and for the right reasons. These technology are explained below: (Four R’s: Right amount, method, time and place). A) Global positioning system:  The Global Positioning System (GPS) is a U.S.-owned utility that provides users with positioning, navigation, and timing (PNT) services.  This system consists of three segments: the space segment, the control segment, and the user segment. The U.S. Air Force develops, maintains, and operates the space and control segments. The space segment consists of constellation of 24 operating satellites that transmit one-way signals that give the current GPS satellite position and time.  The control segment consists of worldwide monitor and control stations that maintain the satellites in their proper orbits through occasional command maneuvers, and adjust the satellite clocks. It tracks the GPS satellites, uploads updated navigational data and maintains health and status of the satellite constellation (group arrangement). 1 Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai  The user segment consists of the GPS receiver equipment, which receives the signals from the GPS satellites and uses the transmitted information to calculate the user's three- dimensional position and time.  The GPS satellites provide service to civilian and military users. The civilian service is freely available to all users on a continuous, worldwide basis. The military service is available to U.S. and allied armed forces as well as approved Government agencies.  The outstanding performance of GPS over many years has earned the confidence of millions of civil users worldwide. It has proven its dependability in the past and promises to be of benefit to users, throughout the world, far into the future. B) Geological information system:  A geographic information system (GIS) is a conceptualized framework that provides the ability to capture and analyze spatial and geographic data.  The GIS applications are computer-based tools that allow the user to create interactive queries (user-created searches), store and edit spatial and non-spatial data, analyze spatial information output, and visually share the results of these operations by presenting them as maps.  Geographic information systems are utilized in multiple technologies, processes, techniques and methods. It is attached to various operations and numerous applications, which are relate to engineering, planning, management, transport/logistics, insurance, telecommunications and business. For this reason, GIS and location intelligence applications are at the foundation of location-enabled services that rely on geographic analysis and visualization.  GIS provides the capability to relate previously unrelated information, through the use of location as the “key index variable”. Locations and extents that are found in the Earth’s space time, are able to be recorded through the date and time of occurrence, along with x, y, and z coordinates; representing, longitude (x), latitude (y), and elevation (z). All Earth- based, spatial–temporal, location and extent references, should be relatable to one another, and ultimately, to a “real” physical location or extent. This key characteristic of GIS, has begun to open new avenues of scientific inquiry and studies. C) Remote sensing: The remote sensing is the process of detecting and monitoring the physical characteristics of an area by measuring its reflected and emitted radiation at a distance (typically from satellite or aircraft). Special cameras collect remotely sensed images, which help researchers to sense things about the Earth. Some examples are:  Sonar systems on ships can be used to create images of the ocean floor without travel to the bottom of the ocean.  Cameras on satellites can be used to make images of temperature changes in the oceans.  Tracking clouds to help predict the weather or watching erupting volcanoes, and help watching for dust storms. D) Variable rate applicator: It is a method of applying varying rates of inputs in appropriate zones throughout a field. The goals of VRA are to maximize profit to its fullest potential, create efficiencies in input application, and ensure sustainability and environmental safety. The variable rate applicator management zones illustrate the natural variability of a field and are used to manage the VRA of inputs across the field. E) Yield monitoring system: These are the sensor based technology which are attached to the combine harvester and helps in measurement of the per unit area yield which can be mapped. These maps help in determining the potential of the area and development of crop cultivation zones. 2  Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai 3. Management: For successful management of precision agriculture, large data need to be handled constructively and for that, different technology provider/ agency need to be searched. These selected agencies will play a role of management. Hire experts Steps in precision farming: Practical steps include a cyclic process of:  Characterization: measure extent, scales and dynamics of variation,  Interpretation: assess significance, identify major causes of uncertainty and formulate management targets.  Management: apply inputs at the appropriate scale and in a timely manner and (d)  Monitoring the outcome in a continuous learning process of change: This may be accomplished in discrete steps (mapping approaches), as dynamic process executed in real-time (sensing approaches and modeling approaches) or as combination of both is also possible. Methods of precision farming: There are two methodologies for implementing precision farming. Each method has unique benefits and can even be used in a complementary or combined fashion. Sr. Particular Map based Sensor based No. Grid Sampling- lab analyses Real time sensors- feedback control 1. Methodology site specific maps and use of measures and use of variable rate variable rate applicator applicator 2. GPS/DGPS Very much required Not necessary Laboratory analyses 3. Required Not required (Plant and soil) 4. Mapping Required May not required 5. Time consumption More Less Cost of soil testing and Lack of sufficient sensors for getting 6. Limitations analyses limits the usage crop and soil information 7. Operation Difficult Easy 8. Skills Required Required 9. Sampling unit 2 to 3 acres Individual spot Popular in Developing 10. Relevance Popular in Developed countries countries Economic feasibility of precision farming (Indian perspective): 1. Hire basis precision agriculture service provider. 2. Government policy and support. 3. Availability of instruments for precision agriculture (VRA, seneors based combine harvester). 4. Training of individual farmers and/ or skilled work force for precision agriculture 5. Land holding and diversity of crop cultivation. 6. Precision farming is important because: (i) Nutrient variability within a field can be very high affecting optimum fertilizer rates, (ii) Yield potential and grain protein can also vary greatly even within one field, affecting fertilizer requirement, (iii) Increasing fertilizer use efficiency will become more important with increasing fertilizer costs and environment concerns, (iv) Irrigation at critical stages is very important and (v) Pest and stress management at early stages helps the farmer to get maximum yield. 3 Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai 7. There is a vast scope for implementing map based precision farming for major rice-wheat cropping system of northern India, as this system is practiced in nearly 8 to 10 m. ha. 8. At the same time, large corporate farms, co-operative agriculture farm and contract farming area are the few important niche for precision agriculture. Constraints: 1. Making the interpretation process more automatic, generic and mechanistic as against empirical, 2. Location-specific remote sensing solutions for integrated crop management program, 3. Developing simple and robust technologies and methodologies, 4. Evaluation at multiple sites with standardized methodologies providing proof of economic and environment benefits and 5. Customization of the precision farming technology to the actual Indian field conditions. The major issues and concerns of precision farming area are as follows: 1. Large diversity of types of crops grown and cultivation practices (example of soil test crop response approach, changes in plant geometry, pattern of nutrient requirement in time dimensions, purpose of crop cultivation, market imperfection low returns on investment) 2. Fragmented land holding and presence of marginal farmers: (Total number operation holding in India is 1464.54 lakh out of which 68.45 % are marginal (< 1 ha) and 17.62 % are small (1-2 ha.); inherited fragmentation of land 3. Difficulty in information collection and maintenance of database at individual farm level (knowledge, facility and enthusiasm of stake holder) 4. Production oriented agriculture emphasizing the yield improvement through resource endowments under subsidized rate 5. Topography of agricultural land and ineffective management of natural resources 6. Risk bearing ability (Income from agriculture and non-agricultural sectors; crop insurance schemes, family requirements and capital availability, rainfed area; climatic factors) 7. Cost effectiveness of technology and their practical feasibility 8. Education level of farmers and social criteria for selection of farmers 9. Difficulties in mechanization of farm (land holding, capital formation, inequitable distribution of resources) 10. Lagging behind in research and development; human resource, capital and policy orientation and regulation authority (give the example of contract farming- Potato in UP Cluster bean in Maharashtra; Tomato in IGP, Central and southern India) 11. Farmer perception and thinking process; going back to organic farming; lack of precision agriculture technology for such situation specific agricultural technology 12. Ultimately it is a dynamic concept (same applicable for agriculture too- give example of Solapur Soghum to cotton to sugarcane to fruits to greenhouse cultivation) which needs to be taken in to consideration before any investments. = = *#* = = Geo-informatics- definition, concepts, tool, techniques and application in agriculture  The term geoinformatics consists of two words, geo (Earth) and informatics (the study of information processing). Hence, geoinformatics can be understood as the union of Earth sciences and Informatics.  The geoinformatics broadly deals with the use of information technology for collection, analysis, storage, retrieval, representation and dissemination of information about the Earth.  Geoinformatics can be defined as the science and technology that deals with the geoinformation, its acquisition, creation, storage, processing, presentation and dissemination. In geoinformatic the meaning of special information/data is wider and it indicates its capacity to be linked to a location on earth. 4  Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai  The geoinformatics uses the modern scientific and technological advancements for better utilization of space to have for sustainable human growth.  The term ‘geoinformatics’ is believed to have come in existence just few decades back as a result of the integration of three disciplines, namely photogrammetry, remote sensing and geographic information systems.  The science and technology which develops and uses information science infrastructure to address the problems of geography, geosciences and related branches of engineering is termed as geoinformatics. Components of geo-informatics: The concept of geoinformatics is revolved around: i) Geology: Study of physical structure and substance of earth. Their history and the processes which act on them. ii) Geodesy: Branch of mathematics which deal with the space and area of earth or large portion of it. The study of geodesy began with mere curiosity and the never-ending human inquisitiveness to explain the Earth’s unknown through logic. It has been a great challenge for researchers to accurately represent the 3-dimensional Earth into 2-dimensional map forms. The underlying concept of geodesy helps in discussing datums, map projections and coordinate systems. iii) GIS: geological information system iv) GPS: Global Positioning System (GPS) is a constellation of about 24 satellites which are orbiting the earth every 12 hours at an altitude of ~20,200 km. These satellites broadcast signals, which are used to derive precise timing, location and velocity information. The derived information can then be clubbed with other systems, such as communication devices, computers, and software to perform a variety of functions. With equipment ranging from hand-held receivers to rack-mounted electronics, the signals of GPS can be used by anyone, anytime, anywhere in the world. GPS technology consisting of space, control and user segments enable people to precisely know where they are on the surface of the earth. Real world applications of GPS fall into following five broad categories:  Location: determining a basic position  Navigation: getting from one location to another  Tracking: monitoring the movement of people, animals and goods  Mapping: creating maps of the world One of the applications of GPS gaining momentum is the Location Based Services (LBS), which are geo- information services that can provide location aware information based on the user’s current position. The LBS are primarily used in emergency services. However, these are also used to provide information on nearby public resources (such as fuel stations, bus stops, ATM machines, etc.), for map and navigation services (such as in vehicles), and even for locating friends though your mobiles. v) Carto-graphy: The science and practice of drawing maps; Cartography is generally considered to be the science and art of designing, constructing and producing maps. It includes almost every operation from original field work to final printing and marketing of maps. It is also treated as a science of human communication. International Cartographic Association defines Cartography as the discipline dealing with the conception, production, dissemination and study of maps. Map is a drawing of the whole or part of the surface of the Earth on a plane surface to a particular scale. It is a manually or mechanically drawn picture of the Earth showing the location and distribution of various natural and cultural phenomena. vi) Geography: The study of physical features of earth and its atmosphere vii) Computer science: (Principles and uses of computers): Comprises of both the computer technologies, i.e. hardware and software. The important role of information derives from our 5  Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai necessity to manage more and more numerous and complex data in every field. Computer science culture is now more prevalent contributing in improvement of our activities and research. The application and usage of computer science to geoinformatics is common in data acquisition, processing, product generation, data visualisation, dissemination, etc. viii) Remote sensing: Scanning of earth by satellite of high-flying aircraft in order to obtain information about it; Remote sensing is the collection of data about an object from a distance and it is used to monitor or measure phenomena found in the Earth’s lithosphere, biosphere, hydrosphere and atmosphere. Humans and many other types of animals accomplish this task with aid of eyes or by the sense of smell or hearing. Remote sensing is usually done with the help of mechanical device known as remote sensor. This device has greatly improved ability to receive and record information about an object without having any physical contact with them. Often, these sensors are positioned away from the object of interest by using helicopters, planes, and satellites. Most remote sensing devices record information about an object by measuring an object’s transmission of electromagnetic energy from reflecting and radiating surfaces. The simplest form of remote sensing uses photographic cameras to record information from visible or near infrared wavelengths of the electromagnetic spectrum. The sun is the principal source of energy and when the energy (in the form of electromagnetic radiation) reaches the earth’s atmosphere, it undergoes the process of reflection, absorption and transmission. The earth’s surface consists of different natural and man-made features which reflect, absorb, store and emit earth’s radiation at different wavelengths in different percentages, depending upon their physical and chemical properties. The remote sensing sensors record different amount of radiation that is reflected or emitted from different earth surface features and reproduce it in form of an image. The remote sensing may of two types: 1. Passive remote sensing: Solar energy is used; 2. Active remote sensing: Remote sensors such as radars send radiation themselves and collect the signal returned back to them from earth surface features. Based on the factors, such as portion of the electromagnetic spectrum used and the number of bands, sensors are generally categorized into optical and microwave: a) Optical sensors: These operate in the region between 0.3 and 15 μm of the electromagnetic spectrum. b) Microwave sensors: These operate in the microwave region of the electromagnetic spectrum (EMS) (wavelength of 1 millimeter to 1 meter; and frequency varies from 30 MHz to 300 GHz). ix) Photo-grammetry: Art, science and techniques of obtaining information about the object using photograph, energy or other phenomenon. Although, both maps and aerial photographs present a ‘bird’s eye-view’ of the earth, aerial photographs are not maps. Maps are orthogonal representations of the Earth’s surface, meaning that they are directionally and geometrically accurate (at least within the limitations imposed by projecting a 3-dimensional object into 2-dimensions). Aerial photographs, on the other hand, display a high degree of radial distortion. In other words, the topography is distorted and until corrections are made for the distortion, measurements made from a photograph are not accurate. Nevertheless, aerial photographs are a powerful tool for studying the Earth’s environment. x) Spatial decision support systems (SDSS): These are designed to help growers to solve complex spatial problems and to make decision concerning to irrigation scheduling, fertilization, use of crop growth regulators and other chemicals. Spatial decision support systems have evolved in parallel with decision support systems (DSS). In addition, in order to effectively support decision- 6  Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai making for complex spatial problems, a SDSS will need to:  Provide for spatial data input  Allow storage of complex structures common in spatial data  Include analytical techniques that are unique to spatial analysis  Provide output in the form of maps and other spatial forms SDSS provide a framework for integrating: 1. Analytical modeling capabilities 2. Database management systems 3. Graphical display capabilities 4. Tabular reporting capabilities 5. The decision-maker's expert knowledge. xi) Yield mapping: The soil sampling and yield mapping tend to be the first stage in implementing precision farming. Yield maps are produced by processing data from an adapted combine that has a vehicle positioning system integrated with a yield recording system. Massey Ferguson were the first company to produce a commercial yield mapping combine. This combine has a Differential Global Positioning System (DGPS) fitted to it that can be identified by the GPS receiver on the roof of the cab and the differential aerial above the engine. The output from the combine is a data file that recorded every 1.2 seconds the position of the combine in Longitude and Latitude, with the yield at that point. This data set can then be processed by various geo-statistical techniques into a yield map. xii) Crop simulation models: Simulation: An approximate imitation of operation of a system or process Model: Representation of complex processes in living/ non-living things in to simple mathematical equations. These models predict the likely yield response to different levels of a particular input. Such models offer a cost effective way in which agronomic knowledge accumulated from numerous previous experiments, usually with treatments of uniformly applied inputs on small and relatively homogenous plots, can be extended to larger spatially-variable fields. Crop simulation models are needed to help consultants, researchers, and other farm advisors determine the pattern of field management that optimizes production or profit. However, the effective use of these tools requires their evaluation in fields to be optimized, their integration with other information tools such as GIS, geostatistics, remote sensing and optimization analysis. Crop simulation models like CERES (maize, wheat, rice, sorghum, barley, and millet) CROPGRO (soybean, peanut, dry bean, and tomato), SUBSTOR (potato), CROPSIM (cassava), and CANEGRO (Sugarcane) models has been developed by researchers from several countries. These models respond to weather, soil water holding and root growth characteristics, cultivar, water management, nitrogen management and row spacing/plant population. InfoCrop is one such Indian model. xiii) Variable rate technology: The variable rate technology is the most advanced component of precision farming technologies, provides "on-the-fly" delivery of field inputs. A GPS receiver is mounted on a truck so that a field location can easily be recognized. An in-vehicle computer, which contains the input recommendation maps, controls the distribution valves to provide a suitable input mix by comparing to the positional information received from the GPS receiver. Current commercial VRT systems are either map-based or sensor-based. The map based VRT systems require a GPS/DGPS geo-referenced location and a command unit that stores a plan of the desired application rates for each field location. The sensor-based VRT systems do not require a geo-referenced location but include a dynamic control unit, which specifies application through real time analysis of soil and/or crop sensor 7  Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai measurements for each field location. New VRT systems like the manure applicator being developed at Purdue University may soon enable precise application of manure in cropping systems. There are two methods of VRT such as: 1) The first method, Map-based, includes the following steps: grid sampling a field, performing laboratory analyses of the soil samples, generating a site-specific map of the properties and finally using this map to control a variable-rate applicator. During the sampling and application steps, a positioning system, usually DGPS (Differential Global Positioning System) is used to identify the current location in the field. 2) The second method, Sensor-based, utilizes real-time sensors and feedback control to measure the desired properties on-the-go, usually soil properties or crop characteristics, and immediately use this signal to control the variable-rate applicator. = = *#* = = Crop discrimination: Concept and significance in GPS/ Precision farming Crop Discrimination: It is the act of differentiation of something/ objects with considering the one or few characteristics or attributes. The word discrimination is mostly used in the context of unjustified or illogical differentiation mainly between human being and sometimes also between any other living things. In case of precision farming, the term discrimination is second step after identification of variability. The discrimination is essential in precision agriculture because of the following: 1. To categories the vegetation based on different criteria 2. To set the management zones 3. To quantify the amount of input need to be applied based on the characteristics of discrimination 4. Significant application in weed management and ecological studied 5. To identify the specific stress on crop growth as well as identification of response to the applied inputs/ treatments in terms of vegetation growth and crop yield. 6. To see the effect of natural calamities on the natural vegetation 7. Monitoring of desert, locust attack affected area, etc. Different crops show distinct phonological characteristics and timings according to their nature of germination, tillering, flowering, boll formation (cotton), ripening etc. Even for the same crop and growing season, the duration and magnitude of each phonological stage can differ between the varieties, which introduce data variability for crop type discrimination with imaging systems. Agricultural crops arc significantly better characterised, classified, modelled and mapped using hyperspcctral data. Crop discrimination is a necessary step for most agricultural monitoring systems. Radar polarimetric responses from various crops strongly relate to the types and orientations of the local scatterers, which make the discrimination still difficult using the polarimetric synthetic aperture radar (PolSAR) technique. Feature Extraction: The process of defining image characteristics or features which effectively provides meaningful information for image interpretation or classification is known as feature extraction. The ultimate goals of feature extraction are:-  Effectiveness and efficiency in classification.  Avoiding redundancy of data.  Identifying useful spatial as well as spectral features.  Maximizing the pattern discrimination For crop type discrimination, spatial features are useful. Crops are planted in rows. either multiple or single rows, as per the crop types for convenience and to maximize yields 8  Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai Different spatial arrangement of the crops gives better spatial information, but it requires high spatial resolution images. In spatial image classification, spatial image elements are combined with spectral properties in reaching a classification decision. Most commonly’ used elements are texture, contexture and geometry (shape). Significance of texture in classification:  As it is possible to distinguish between regular textures manifested by man made objects hence, this texture characteristic is used to discriminate between divergent objects.  The grey value relationship is obtained from segmentation both by conventional texture analysis and grey level co-occurrence matrix (GLCM).  The GLCM can be viewed as two dimensional histogram of the frequency with which pairs of grey level pixels occur in a given spatial relationship, defined by specific inter-pixel distance and a given pixel orientation. Local Binary Pattern (LBP):  It is a simple yet very efficient texture operator which labels the pixels of an image by thresholding the neighbourhood of each pixel and considers the result as a binary number. Due to its discriminative power and computational plainness, LBP texture operator becomes a popular approach.  The spatial feature extraction for crop type discrimination works well if we have high spatial resolution satellite imagery. Rather than this, spatial information is also useful in spectral based classification for visual interpretation in supervised learning. Spectral Features for Crop Classification: 1. Band selection:  Band selection is one of the important steps in hyperspectral remote sensing.  There are to conceptually different approaches of band selection like unsupervised and supervised. Due to a availability of hundreds of spectral bands, there may be same values in several bands which increase the data redundancy,  To avoid the data redundancy and to get distinct features from available hundreds of bands, we have to choose the specific band by studying the reflectance behaviour of crops. 2. Narrow band vegetation indices:  Spectral indices assume that the combined interaction between a small numbers of wavelengths is adequate to describe the biochemical or biophysical interaction between light and matter.  Vegetation properties measured with hyperspectral vegetation indices (HVIs) can be divided into three main categories. (1) Structure, (2) biochemistry and (3) plant physiology/stress. Importance of Hyperspectral Remote Sensing:  The spectrum allows us to study very specific characteristics of agricultural crops  Non-imaging sensors gave spectral signatures with approximate 1-10 nm sampling rate which is very effective for distinct feature identification.  Narrow band vegetation indices play an important role for mapping plant biophysical and biochemical properties of agricultural crops.  It gives detailed information about crops but it is necessary to select appropriate bands Attributes of crop discrimination: Soil organic carbon, vegetative cover on soil surface, etc. = = *#* = = Yield Mapping: Concept The crop yield is not same at all area if recorded at narrow scale (per meter square) even after applying the same input and at same level of management. This might be due to inherent soil variability or due to improper methods of input application leading to non-uniform application of resources. This variation in 9  Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai yield at different point in a field is measured by using different procedure and is called as yield monitoring. The maps are prepared from this data which are the yield map. The yield mapping refers to the process of collecting and plotting of georeferenced data on crop yield and characteristics, such as moisture content, while the crop is being harvested. In present day, a range of sensors are available for mapping crop yields. The equipment was introduced in the early 1990s and is increasingly considered a conventional practice in modern agriculture. This concept of yield monitoring is more common in area where the crops are harvested by using combines as the sensors are effectively fit over the combines harvesters and these harvesters at geo- referred (GPS tractors are available). Yield monitors are a rather recent development and allow farm equipment such as combine harvesters or tractors to gather a huge amount of information, including grain yield, moisture levels, soil properties, and much more. Yield monitors work in three very simple steps: the grain is harvested and fed into the grain elevator which has sensors that read moisture content of the grain. After that process as the grain is being delivered to the holding tank, more sensors monitor the grain yield. The basic components of a grain yield mapping system include: 1. Grain flow sensor – determines grain volume harvested 2. Grain moisture sensor – compensates for grain moisture variability 3. Clean grain elevator speed sensor – used by some mapping systems to improve accuracy of grain flow measurements 4. GPS antenna – receives satellite signal 5. Yield monitor display with a GPS receiver – georeference and record data 6. Header position sensor – distinguishes measurements logged during turns 7. Travel speed sensor – determines the distance the combine travels during a certain logging interval (Sometimes travel speed is measured with a GPS receiver or a radar or ultrasonic sensor.). Each sensor has to be properly calibrated according to the operator’s manual. The calibration converts the sensor’s signal to physical parameters. A proprietary binary log file is created during harvest to record the output of all sensors as a function of time. This file can be converted to a text format or displayed as a map using the yield monitor vendor’s software. Processing Yield Maps The yield calculated at each field location can be displayed on a map using a Geographic Information System (GIS) software package. The raw log file, however, contains points recorded during turns and the sensor measurements do not correspond to the exact harvest locations because grain flow through a combine is a delayed process (unless real-time correction is applied). To eliminate these obvious errors, the raw data is shifted to compensate for the combining delay, and the points corresponding to the header up position are removed. Settings for grain flow delay are combine- and sometimes even crop-specific, but typical values for grain crops range from about 10 to 12 seconds. Shifting of raw data to correct for grain flow delay as well as deletion of points that represent header status up and start-and end-pass delays is the primary data filtering procedure built into software supplied with yield mapping systems. Yield history evaluation: Evaluating the temporal (year-to-year) variation of yield distribution within the field is an essential step in defining field areas with potentially high and low yields. Several approaches can be used to evaluate temporal effects on yield. One approach is to calculate the relative (normalized) yield for each point or grid cell. Normalized yield can be defined as the ratio of the actual yield to the field average: 10  Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai Potential applications:  Yield maps represent the output of crop production.  This information can be used to investigate the existence of spatially variable yield limiting factors.  The yield history can be used to define spatially variable yield goals that may allow varying inputs according to expected field productivity.  The yield monitoring and mapping helps in site-specific management of different inputs.  The yield maps are also show the effect of input application and management.  The yield monitoring are important for the soil properties which are corrected as per the requirement by following the site specific recommendations in single or two years. Significance and consideration of yield mapping: Map averaging or smoothing is usually done to aid data interpretation. A long yield history is essential to avoid drawing conclusions that are affected by the weather or other unpredictable factors during a particular year. Typically, at least five years of yield maps are desired. Yield Monitoring is an aspect of precision agriculture that helps to provide farmers with adequate information to make educated decisions about their fields. When growing conditions in a field vary considerably, such as irrigated and dryland areas or different crops or varieties grown in different areas, normalization should be done separately for those areas, with the resulting relative yields recombined into one data file for the whole field. Fundamental Pieces of a Yield Monitor: The yield monitors have variances between each model, although there are some defining pieces of equipments that are used in the yield monitoring process. These sensors are key components of the yield monitoring process and help to provide further knowledge for the farmer, as well as more accurate results when collecting data. Mass flow sensor: A mass flow sensor is a sensor that helps to provide the yield monitor with enough information to establish a grain yield measurement. The mass flow sensor works by using a load cell which is fixed to the top of a clean grain elevator. When the harvested grain is fed through the combine it eventually will hit up against this load cell, this is then transformed into an electrical signal and relayed to the yield monitor. The yield monitor uses this reading to determine how much grain is being taken into the combine at any point in time. This sensing method is very common, although there are different methods used, as well as variations of the same method. Moisture Sensor: Being aware of the moisture content in grain that has been harvested can be extremely valuable information for a farmer to know, especially for aspects including harvesting, storing and drying crops. When farmers take these moisture readings they are better able to obtain an accurate market value for their crop. The moisture sensor works when the grain moves in-between two conductive surfaces, which measure how much electric charge the grain can store – this is known as capacitance. There are various places to mount the moisture sensor, and it is a vital step of the yield monitoring process. GPS Receiver: A GPS Receiver, or global positioning system receiver, is a remote sensor that measures a variety of different pieces of data, including where the equipment is located, speed, altitude, and much more. A GPS receiver is a primary component when geo-referencing, as the GPS receiver helps to record the position of the equipment in use, then sends that data to an onboard computer which then connects it with all other information that the computer has collected at that particular location. The GPS receiver is one of the key components that can help to transform yield monitoring data from graphs and charts, into tangible maps that the farmer can use. 11  Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai Yield Monitor: Sometimes referred to as a task computer, receiver, or yield monitor; this piece of technology is the monitor that is located in the cab of the combine or tractor. This piece of equipment serves many different purposes, although its main function is to display the information gathered by the different onboard sensors to allow the operator to know in a real time manner different moisture levels, crop yield and more. These monitors also have the capability to store memory as well as transfer memory to a laptop or home computer. This transfer of memory makes analyzing data a much more comfortable experience, and it also provides the capability of using more software to interpret and render the data collected by the yield monitoring system. The GreenStar yield mapping system, Advanced Farming System, a mass-flow yield monitor, Micro-Trak and Satloc yield monitoring system are the some yield monitoring system. = = *#* = = Image processing and interpretation: Remote sensing: Remote Sensing is the science and art of obtaining information about an object/phenomena or area through the analysis of data acquired by a device that is not in contact with the object under investigation. Analysis of remote sensing image: Analysis of remote sensing image often involves identification of various features such as forest cover, water bodies, urban settlement, agriculture and range land etc. These features are identified by the way they reflect or emit radiations and also by their association and location. Visual interpretation elements: Identifying individual features from images is a key to interpretation and information extraction. Recognizing differences between feature and its background are generally based on some of these visual interpretation keys generally known visual interpretation elements, viz., shape, size, pattern, tone, texture, shadow and association. s 12  Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai Interpretation: Interpretation is the processes of detection, identification, description and assessment of significant of an object and pattern imaged. The method of interpretation may be either visual or digital or combination of both. Both the interpretation techniques have merits and demerits and even after the digital analysis the output are also visually analysed. Basic elements of interpretation: Shape: The external form, outline or configuration of the object. This includes natural features (Example: Yamuna River), in Delhi Man Made feature (Example: Nehru Stadium, Delhi). Size: This property depends on the scale and resolution of the image/photo. Smaller feature will be easily indented in large scale image/photo. Pattern: Spatial arrangement of an object into distinctive recurring forms: This can be easily explained through the pattern of a road and railway line. Even though both looks linear, major roads associated with steep curves and many intersection with minor road. Shadow: Indicates the outline of an object and its length which is useful is measuring the height of an object. The shadow effect in Radar images is due to look angle and slope of the terrain. Taller features cast larger shadows than shorter features. Tone: Refers to the colour or relative brightness of an object. The tonal variation is due to the reflection, emittance, transmission or absorption character of an object. This may vary from one object to another and also changes with reference to different bands. In General smooth surface tends to have high reflectance, rougher surface less reflectance. This phenomenon can be easily explained through Infrared and Radar imagery. Texture: The frequency of tonal change. It creaks a visual impression of surface roughness or smoothness of objects. This property depends upon the size, shape, pattern and shadow: Location Site: The relationship of feature to the surrounding features provides clues to words its identity. Example: certain tree species words associated with high altitude areas 13  Geoinformatics, Nanotechnology and Precision Farming Class Notes (For 2023 academic use) COA, CAU-I, Kyedemkulai, Meghalaya. (Dr. A. A. Shahane, Assist. Professor (Agronomy), COA, CAU-I, Kyrdemkulai Resolution: It depends upon the photographic/imaging device namely cameras or sensors. This includes of spectral and spatial resolutions. The spectral resolution helps in identifying the feature in specific spectral bands. The high spatial resolutions imagery/photographs is useful in identifying small objects. Association: Occurrence of features in relation to others. Issues in interpretation  Unfamiliar scale and resolutions.  Lack of understanding of physics of remote sensing.  Understanding proper spectral character of each object  Training and Experience of the interpreter  Quality of photo/Images  Local knowledge of the study area. Advantages in visual Interpretation  Simple method  Inexpensive equipment  Uses brightness and spatial content of the image  Subjective and qualitative  Concrete Advantages of digital image processing:  Cost-effective for large geographic areas  Cost-effective for repetitive interpretations  Cost-effective for standard image formats  Consistent results  Simultaneous interpretations of several channels  Complex interpretation algorithms possible  Speed may be an advantage  Explore alternatives  Compatible with other digital data Disadvantages in digital processing:  Expensive for small areas  Expensive for one-time interpretations  Start-up costs may be high  Requires elaborate, single-purpose equipment  Requires standard image formats  Data may be expensive, or not available  Preprocessing may be required  May require large support staff. = = *#* = = 14