Agricultural production follows a strong seasonal pattern related to the natural lifecycle of crops and weather. Farmers track the physical landscape, such as soil type and other climatic driving variables like moisture, to make many day-to-day decisions and plan efficiently to minimize costs and maximize yields and profits as a result. Productivity can change within a short time due to unfavorable growing conditions.
Therefore, the use of remote sensing is indispensable in the monitoring of agricultural land, crop, soil health, water management, and atmospheric conditions with emphasis to yield.
What is remote sensing? Remote sensing is all about acquiring information about the Earth’s surface by measuring the reflected or emitted radiation without coming into direct contact with the object. This process involves an interaction between incident radiation and the targets. The most useful electromagnetic radiation in remote sensing includes visible light (VIS), near infra-red (NIR), and shortwave infrared (SWIR) to thermal infrared (TIR) and microwave bands.
In the last two decades, remote sensing has been applied to explore agricultural applications such as crop acreage estimation, crop discrimination, soil moisture estimation, crop condition assessment, yield estimation, precision agriculture, soil survey, agriculture water management, agro-meteorological and agro advisories.
Remote sensing of agricultural canopies has provided valuable insights into various agronomic parameters. Its advantage is the ability to provide repeated information without a destructive sampling of the crop. Remote sensing is a cheap alternative for data acquisition over large geographical areas.
The application of remote sensing in agriculture, i.e., in crops and soils, is too complicated because of the highly dynamic and inherent complexity of biological materials and soils. However, technology provides many advantages over traditional methods. They include:
- the capability of synoptic view
- potential for fast survey
- the ability of repetitive coverage to detect the changes
- low-cost involvement
- higher accuracy
- use of hyperspectral data for increased information.
Let’s now look at some of the top applications of remote sensing in the agricultural sector.
Monitoring of vegetation cover: Remote sensing plays a vital role in the area of crop classification, crop acreage estimation, and yield assessment. Many research experiments were done using aerial photographs and digital image processing techniques. However, the field of remote sensing helps in reducing the amount of field data to be collected and improves the higher precision of estimates.
Crop production forecasting: Remote sensing allows researchers and farmers to forecast the expected crop production over a given area and determine how much crop can be harvested under specific conditions. Researchers can also predict the quantity of crops in given farmland over a given period, depending on many factors including crop variety, water, and nutrient status of the field, influence by weeds, pest and disease infestation, weather parameters.
Assessment of crop condition, damage, and crop progress: Remote sensing can play an important role in agriculture by providing timely spectral information to assess the biophysical indicators of plant health. In the event of crop damage or crop progress, remote sensing technology is used to penetrate the farmland and determine precisely how much of a given crop has been damaged and the progress of the remaining crop on the farm.
Crop identification: Remote sensing has played an essential role in crop identification, especially when the crop under observation shows some mysterious characteristics. The collected crop data will is taken to labs where various aspects of the crop, including the crop culture, are studied.
Crop acreage estimation: Remote sensing has also played a vital role in estimating the farmland on which a crop has been planted. This is usually a cumbersome procedure if carried out manually because of the vast sizes of the lands being estimated.
Crop yield modelling and estimation: Remote sensing also allows farmers and experts to predict the expected crop yield from given farmland by estimating the crop’s quality and the extent of the farmland. This is then used to determine the overall expected yield of the crop.
Identification of pests and disease infestation: Remote sensing has become an essential tool for monitoring and quantifying crop stress due to biotic and abiotic factors. It plays a significant role in identifying pests in farmland and gives data on the right pests control mechanism to get rid of the pests and diseases on the farm.
Weed identification and management: Precision weed management technique helps in carrying out better weed management practices. Remote sensing, coupled with precision agriculture, is a promising technology in nowadays. Though, ground surveying methods for mapping site-specific information about weeds are very time–consuming and labor-intensive. However, image-based remote sensing has potential applications in weed detection for site-specific weed management.
Soil moisture estimation: Soil moisture can be difficult to measure without remote sensing. Using remote sensing, farmers can acquire the soil moisture data, helping them determine the quantity of moisture in the soil and the type of crop grown in the soil.
Soil mapping: Soil mapping is one of the most common yet most essential uses of remote sensing. Through soil mapping, farmers can tell which soils are ideal for which crops and which soil require irrigation, and which ones do not. This information helps in precision agriculture.
Monitoring of droughts: Remote sensing technology can monitor the weather pattern of a given area. It monitors drought patterns too. The data can be used to predict the rainfall patterns of an area and tell the time difference between the current rainfall and the next rainfall. This helps keep track of the drought.
Water resources mapping: Remote sensing is key in mapping water resources over farmland that can be used for agriculture. Through remote sensing, the farmers can tell where water resources are available for use on a given land and if they are adequate.