Satellite remote sensing: Using technology to boost agricultural development

Agricultural environmental monitoring is not only an important technical means for agricultural environmental management, but also a crucial component of monitoring the broader human living environment. Its fundamental purpose is to reflect the quality of the agricultural environment, its changing patterns, and development trends in a timely, accurate, and comprehensive manner; to track the dynamics of pollutant residues and accumulations in agricultural, livestock, and aquatic products; to ensure the safety of agricultural products and human health; and to provide a scientific basis for agricultural environmental management. Through this approach, farmers can adopt feasible methods for fertilization, plant protection, quantitative irrigation, and more agricultural activities, thereby increasing crop yields and minimizing pressure on the natural environment.

The principle of agricultural monitoring using remote sensing satellites

When dealing with large tracts of land in agriculture, remote sensing technology enables large-scale, high-frequency long-term observation of crops on the ground, and is widely applied in all aspects of agricultural production. The reflectance and its combination in the red and near-infrared bands of remote sensing imagery show good correlations with crop leaf area index, solar photosynthetically active radiation, and biomass. Information about the Earth's surface recorded by satellite sensors helps determine the unique characteristics of certain plant species, identify crop types, establish yield forecasting models under different conditions, and integrate agronomical knowledge with remote sensing observation data to achieve remote sensing monitoring and forecasting of crop yields.
In 2018, the Gaofen-6 satellite was successfully launched from the Jiuquan Satellite Launch Center in Gansu Province. It is the first satellite in my country specifically designed for agricultural applications, featuring a red-edge band sensor, and is also my country's first high-resolution satellite for precision agriculture observation. Gaofen-6 combines high resolution with broad coverage and will operate in conjunction with the already orbiting Gaofen-1 satellite, significantly enhancing Earth observation capabilities.

Specific applications of satellite remote sensing technology in agriculture

Satellite remote sensing technology plays a significant role in crop growth monitoring and yield prediction, agricultural disaster monitoring and early warning, and ecological environment meteorological monitoring and assessment. Its applications in agriculture can be mainly summarized as crop monitoring, agricultural resource surveys, agricultural disaster early warning, and agricultural financial services.

Crop growth monitoring

Crop growth remote sensing monitoring uses remote sensing data to make macroscopic estimates of real-time crop seedling conditions, environmental dynamics, and distribution. It allows for timely understanding of crop distribution, growth status, fertilizer and water conditions, and the dynamics of pests, diseases, and weeds, facilitating the implementation of various management measures and providing a timely and accurate data information platform for crop production managers or management decision-makers.

Traditional methods of assessing crop growth require farmers to visit fields in person, which is extremely physically demanding. However, using satellite remote sensing to monitor crops allows for remote observation of crop growth. This method is more scientific than traditional manual inspection and can better grasp the overall growth status of crops in the field. It significantly reduces the manpower required for farmers to inspect crop growth, lowers their labor intensity, and increases efficiency.

Monitoring water conditions

Satellite remote sensing technology can record the salinity and health status of soil. When there is a high concentration of salt, the technology will highlight that area in a brighter color, indicating to farmers that the soil needs more water and requires treatment. In contrast, thermal sensors can detect areas of water shortage. This is done by monitoring heat, which is then displayed in a lighter shade.

Monitoring and assessing agricultural water resources is crucial for achieving sustainable food security and development. Precision agriculture remote sensing has successfully provided accurate and timely information on water bodies, irrigated farmland, crop and soil moisture conditions at various scales.

Monitoring soil conditions

For precision agriculture, soil monitoring is crucial. Key soil parameters for optimizing crop management include soil organic matter (SOM), soil texture, soil pH, and moisture content. Periodic monitoring using remote sensing technology is extremely helpful in understanding soil fertility. Remote sensing devices will alert the field when a specific micronutrient is deficient and falls below a certain standard, allowing for proactive assessment in soil fertility management. Agricultural remote sensing technology will also provide information on canopy health, growth stage, yield, biomass, and nutrient density. To study changes in crop growth patterns, it is necessary to emphasize the link between crop performance and soil conditions.

Crop disease and pest detection

In agricultural production, the traditional method of monitoring pests and diseases involves on-site sampling and testing, which is very time-consuming and labor-intensive. Although it has been effective in controlling pests and diseases to a certain extent, it is difficult to achieve large-scale application due to the limitations of the technology.

Using remote sensing technology to monitor pests and diseases in the fields can reduce the need for farmers to frequently patrol the fields, thus lowering their labor intensity. Once pests or diseases occur, remote sensing technology can determine the affected area and other details, allowing for targeted treatment measures. This avoids the need for farmers to use large amounts of pesticides for prevention, promoting the scientific use of pesticides and improving economic efficiency. Simultaneously, it strengthens field monitoring, thereby reducing pesticide use and lowering costs for farmers, while also mitigating or eliminating pesticide residues in grains and improving grain quality.

Monitoring and predicting climate change

In agriculture and agronomy, weather plays a crucial role and determines yield outcomes. Satellite remote sensing technology, capable of predicting weather conditions, is a valuable tool for accurately forecasting climate change. Combining this technology with ground-based sensors allows for the detection of weather and climate change, helping agricultural practitioners plan future damage control and reduce collateral damage. It can also predict other natural disasters, providing as much time as possible to save crops.

Currently, satellite remote sensing technology has been applied to the development of smart agriculture in many regions, including Northeast China, Shaanxi, Ningxia, Henan, Jiangsu, and Hainan, promoting the digital transformation of agriculture nationwide. A bountiful harvest depends not only on favorable weather conditions but also on the improvement of comprehensive grain production capacity supported by agricultural technology. As the carrying capacity of natural resources and the environment becomes increasingly strained, agricultural production activities face more constraints. Improving resource utilization efficiency and promoting increased agricultural production and quality through technologies such as satellite remote sensing are key measures for high-quality development of agricultural production.

Some content in this article is sourced from:

Erte Data Technology, Agricultural Water-Saving Equipment Research Branch