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- Sea of onions: the amount of fertilizer for the fields was determined by satellites
Sea of onions: the amount of fertilizer for the fields was determined by satellites
Scientists studying onion fields have established the ratio of biophysical indicators of plants, which were measured by ground-based means and with the help of Earth remote sensing spacecraft. Based on the obtained data, the specialists built a computational model that allows to quickly calculate fertilizer application and other operations for optimal onion growth. Implementation of the development will reduce the cost of field research and help automate these processes, the developers believe. The model can be adapted for other crops as well.
How to technologically grow leeks
Russian scientists together with colleagues from Egypt have studied fields sown with leeks and established dependencies between changes in biophysical characteristics of plants and spectral vegetation indices, which are obtained by spacecraft. Specialists from the Peoples' Friendship University of Russia named after Patrice Lumumba, Cairo University and the National Remote Sensing and Space Science Authority of Egypt took part in the work.
According to the researchers, the data obtained can become the basis for the development of software systems based on neural networks for automatic control of fertilizer application and plant care processes. Digital methods will cut costs by reducing routine manual labor and increase crop yields.
- Leek is one of the important crops in Egypt. It is part of the daily diet of the inhabitants and is used in many local cuisine recipes. In addition, Egypt is one of the top three onion exporting countries. Therefore, farmers are striving to increase the yield of the crop and apply advanced agricultural technologies," Abdelrauf Ali, one of the authors of the study, associate professor of the Department of Environmental Management at the Institute of Ecology of PFUR, told Izvestia.
According to him, in the course of scientific work agronomists studied how foliar feeding with nanoparticles of magnesium oxide - a significant element in plant physiology - affects the change in biophysical characteristics of the crop. The research was conducted over two seasons in 12 fields in Ismailia governorate (district) in northeastern Egypt.
During the study, experts manually collected leaf samples and used them to calculate the biophysical characteristics of the plants. Such as, for example, the area of ground surface covered by leaves or the amount of radiation the plants absorbed during photosynthesis. These indicators provide an objective view of crop growth and viability.
Space technology in agriculture
The scientists then correlated the results with data obtained from space. Specifically, they examined seven vegetation indices that were calculated from images taken by the Sentinel-2 orbiter, a European satellite for monitoring vegetation, forests and water resources.
- Direct methods of measuring plant health are time-consuming and labor-intensive, and provide only a localized assessment. Remote sensing methods can replace them," Abdelraouf Ali noted.
He said that vegetation indices are numerical indicators that characterize the state of vegetation cover. They are determined on the basis of Earth remote sensing (ERS) data - registration of electromagnetic waves emitted or reflected by the Earth's surface and measurement of their intensity in different spectral channels.
As the scientist explained, such indicators include, in particular, biomass indices, which are determined by calculating the absorption of visible light by plants. Another group consists of indices of moisture storage in the vegetation cover. These parameters can be identified by the delay of the signal sent from a satellite and reflected from the ground.
- The data obtained in field experiments and by satellite proved to be close even in "raw" form. The correlation between them in the first season amounted to 66%, and in the second season, after refining the methodology, - up to 89%. Based on this information, the agronomists developed a more accurate linear model. Based on satellite readings, it predicts leaf area index with a correlation of 90-91%. This shows that simple computer calculations can replace labor-intensive field measurements with high accuracy," Abdelrauf Ali summarized the results of the scientific work.
He added that refinement of the model will allow, for example, to quickly calculate the amount of fertilizers that need to be applied to maintain optimal growth of onions. Further development of the project will help to reduce the share of costly field measurements and automate agricultural production to a greater extent. Once adapted, the model can then be applied to other crops, such as peas, beans and mustard.
How satellite data can be used
- At the moment, space technology has reached a level where it is possible to analyze the state of the crop from space. But there are nuances that are related to the terrain, lighting, seed quality and other features. Therefore, in order to effectively apply mathematical models, we need to use neural networks. They will allow to retrain the programs on a particular crop," Oleg Slepets, an expert of the GLONASS/GNSS-Forum Association, deputy general director of the United National Dispatch System - Orel LLC, told Izvestia.
Also, in his opinion, in order to replicate the experience of using such models, it is necessary to develop unified measurement standards. This requires certification of many measuring devices. Only the state can undertake such a task. At the same time, there is a lot of work on digitalization of agriculture in our country, but there are few practical examples. Therefore, the experience of Russian and Egyptian scientists should be studied.
- Often remote sensing of the Earth does not provide sufficient resolution. This should be compensated for by comparing different sources. For example, images from space can be supplemented with unmanned aviation data," says Ruslan Brezhnev, Head of the Space Monitoring Information Support Laboratory at the Institute of Space and Information Technologies of the Siberian Federal University.
Satellite technologies are significantly changing the face of agriculture, the expert noted. This is largely due to the introduction of unmanned equipment - tractors, combines and other machines. In particular, it turned out to be more advantageous that the field was round, because there are no sharp turns when the machine moves in a spiral from the center to the periphery. This is easier from a control point of view and also reduces fuel consumption and processing time.
- Remote sensing data as a commercial product began to be applied to agriculture in the late 1990s. At that time, these services did not fit well with "pre-digital" processes, but now the situation is different. Agroholdings are actively using these technologies because they are relatively easy to integrate into other processes," said Andrey Ionin, Advisor to the General Director of Geoscan Group of Companies.
For example, he said, remote sensing is used for land inventory, crop monitoring, forecasting of volumes and quality of agricultural products, assessment of factors (weather, environmental) that affect crop yields.
The expert emphasized that now space images are probably the most cost-effective tool, as they allow "without leaving the office" to obtain objective information about large areas of agricultural lands, which are thousands of kilometers away from the control center. Based on this information, banks allocate loans, insurance companies manage risks, and government agencies monitor the effectiveness of subsidies and calculate taxes and fines (for example, for environmental violations).
Unfortunately, noted Andrei Ionin, today Russia cannot boast the scale of remote sensing constellation. But, on the other hand, our country is becoming a leader in the production and export of agricultural products, as well as in the creation and use of aerial drones. This gives us confidence that such systems will soon appear in sufficient quantities. This will reduce the risks for investments in satellite development, which will make it possible to increase domestic space constellations.
Переведено сервисом «Яндекс Переводчик»
