Agriculture is the backbone of any economy in the world. Producing food of sufficient quantity and quality is essential for the well-being of its population. Agricultural plants require water and nutrients in order to grow and are sensitive to extreme weather phenomena, diseases and pests. In such a scenario, remote sensing (RS) can provide important data that can help identify and monitor crops.
When these data are organized in a Geographical Information System or GIS along with other types of data, it becomes an important tool that helps farmers make decisions about crops and agricultural strategies.
What Is Remote Sensing And What Is It Used For?
Remote sensing (RS) is the process of monitoring the physical characteristics of a region by measuring it’s reflected and emitted radiation at a remote location – typically from satellite or aircraft.
This is achieved with the help of special high resolution cameras that collect remotely sensed images of the landscape.
The term ‘remote sensing’ was first used in the U. S. in the 1950’s by Ms. Evelyn Pruitt of the U.S. Office of Naval Research. It refers to the activities of recording/ observing/perceiving (sensing) objects at far away or remote locations.
Aronoff in 1995 defined RS as the science of obtaining information from a distance, i.e. obtaining information about objects without being in physical contact with them.
In remote sensing systems, the active sensors are not in direct contact with the objects that are actually sensed. The information needs a physical carrier to travel from the objects to the sensors through an intervening medium. The carrier in it is generally electromagnetic spectrum.
Examples of Remote Sensing Technology in Everyday Life
Some specific examples where remote sensing technology is used:
- Cameras on aero planes and satellites take images of large areas on the earth’s surface, allowing scientists to have a much more view of the landscape than they can see by standing on the ground.
- Sonar systems on ships use this technology to create images of the ocean floor without the need to travel to the bottom of the ocean.
- Large forest fires can be mapped by RS cameras from space, allowing rangers to have a clear picture of the forest fire, as it displays much larger areas affected by a forest fire.
- The widespread use of this technology is seen in tracking clouds to help predict the weather and help to watch for dust storms.
- Remote sensing data makes it possible to map the rugged topography of the ocean floor (for example, huge mountain ranges, deep canyons, and also magnetic striping on the ocean floor).
Benefits of Remote Sensing In Agriculture
1 Large agricultural area coverage
This technology can cover very large areas, which enable regional surveys on a variety of themes. Moreover, RS is a relatively expensive method of analysis, especially when analyzing smaller areas and hence are used for large areas.
2 Repetitive coverage
RS allows repetitive coverage of agricultural land where data can be collected on dynamic themes such as water and agricultural fields.
3 Remote sensing is unobstructed
Meaning a remote sensor will passively record the electromagnetic energy reflected from or emitted by the object of interest, in this case, the agricultural land. This means that passive RS does not actually disturb the object being sensed.
4 Multi-use of a single image
A single image captured through RS can be interpreted and analyzed for use in various applications. There is, however, no limitation on the extent of information that can be collected from a single remotely sensed image of farmland.
5 Minimizes field activities
Data collected through remote sensors are analyzed at the laboratory, which minimizes the work that needs to be carried out in the farmland.
6 Allows map revisions
RS allows for map revision at a small to medium scale, which makes it not only cheaper but faster also.
7 Easy tracking of forest fires and floods
With the help of RS technology, it is easier to locate natural calamities like floods, forest fires or volcanic eruptions that have spread over a large region. The available data makes it easier to plan a rescue operation easily and in a short time span.
8 Cheaper Option
RS is a relatively cheap and constructive method of reconstructing a base map in the absence of detailed land survey methods in case of difficult terrains.
Remote Sensing Applications in Agriculture
The phenomenon of RS has numerous applications, including photography, geology, forestry, surveying natural resources and many more. But it is in the agricultural sector that RS has found significant use. There are very many applications of RS in the agricultural sector; below is a long list of these applications.
A. Remote Sensing Applications in Agriculture – Crop Productivity Management
The assessment of agricultural crops provides valuable insight into the agronomic parameters. RS is playing a significant role in crop monitoring crop classification and yield assessment. Few examples:
1 Crop production forecasting: RS is extensively used to forecast the expected crop production and yield over a given region and assess how much of the crop could be harvested under specific conditions. In today’s condition, the use of RS has become a critical step in forecasting crop yields in a particular region.
2 Crop identification: RS is used in crop identification, especially in cases where the crop under observation shows some mysterious characteristics. The crop production-related data is collected and are analyzed in the labs, where various aspects of the crop, including the crop culture, are studied.
4 Assessment of crop progress and crop damage: In order to predict crop damage or crop progress, RS technology is used to penetrate the farmland and determine exactly how much of a given crop is damaged and also the progress of the remaining crop on the farm.
5 Horticulture, cropping systems analysis: RS technology is extensively used in the analysis of various crop planting systems. This technology is used in the horticulture industry, where flower growth patterns are analyzed in detail and a prediction made out of the analysis.
B. Remote Sensing Applications in Agriculture – Crop Water Management
Information on water use, crop-water demand, soil moisture condition, and related plant growth at different stages of cultivation can easily be obtained through the use of various forms of RS. Few such examples are:
1 Irrigation monitoring and management: The main challenge being faced by crop irrigation is that of water management, especially in regions where water availability is less. RS gives information on the moisture content of the soils. This information is then used to determine whether a particular soil is moisture deficient or not and helps in planning the irrigation needs of the farm.
2 Drought monitoring: RS technology is used to monitor the weather patterns, primarily the drought patterns over a given region. The information is also used to predict the rainfall patterns of that specific region and also tell the time difference between the current rainfall and the next expected rainfall. This helps to keep track of the drought condition of that region.
3 Flood mapping and monitoring: By using RS technology, agricultural experts and farmers are able to map out the regions that are likely to be hit by floods and also the regions that lack proper drainage. This data is very helpful in averting any flood disaster in the future.
4 Water resources mapping: RS is instrumental in the mapping of water resources that are widely used for agriculture over given farmland. Through RS technology guided by satellite imagery data, farmers can conveniently tell what water resources are available for use over the given landscape and whether the resources are adequate for crop production.
5 Collection of weather data: RS technology is ideal for collecting and storing past and current weather data of a region, which can be used for future decision making and prediction. This includes collecting the wind speed data.
C. Remote Sensing Applications in Agriculture – Soil Characteristics
Numerous studies and practical projects have demonstrated the utility of RS for distinguishing various soil properties. These include erosion prediction, soil organic carbon, application of agrochemicals to soils, iron oxide content, soil texture and more. Few examples:
1 Soil moisture estimation: Soil moisture is an important variable in land surface hydrology as it controls the quantity of water infiltrating into the soil. Soil moisture is a parameter that can be difficult to measure without the help of RS technology. RS provides real-time soil moisture data and helps in determining the quantity of moisture in the soil. This, in turn, helps determine the type of crop that can be grown in the soil. The field of RS of soil moisture has expanded greatly and is used by farmers in various applications.
2 Soil mapping: Soil mapping is one of the most common and important uses of RS. The visual images are interpreted and are compared with the existing digital data to prepare a soil map of that specific region. Through soil mapping, farmers are able to tell what soils are ideal for which crops and what soil require irrigation and which ones do not. This information about soil property is also helpful for precision agriculture.
D. Remote Sensing Applications in Agriculture – Crop Analysis & Forecasting
1 Crop yield forecasting: Today, with the use of RS technology, accurate estimates of the expected crop yield can be achieved in a planting season using various crop information such as the crop quality, the moisture level in the soil and the crop cover of the farmland. When all of these data are combined, it gives almost accurate estimates of the crop yield.
2 Identification of planting and harvesting dates: RS technology is becoming popular because of its predictive nature. Farmers today use RS to observe the weather patterns and the soil types to predict the harvesting and planting seasons of each crop.
3 Stress detection and crop condition assessment: RS technology is used to assess the health condition of each crop and the extent to which the crop has withstood stress. This valuable data is then used to determine the quality of the crop in that particular farmland.
4 Identification of pests and disease infestation: Today, identification of pests in the farmland can easily be made with RS technology. The technology can also be used to derive data on the right pests control mechanism to be applied to get rid of the pests and diseases on the farm.