The pace of precision agriculture accelerates the remote sensing into the potential market for agricultural drones

[ China Agricultural Machinery Industry News ] Today's drone flying defense services are gaining momentum, and drones carrying canisters have been widely recognized, but at the same time, another potential application of agricultural drones cannot be ignored. Agricultural remote sensing. Remote sensing is considered to be another potential market for agricultural drones. As agriculture accelerates, remote sensing represents another broad future for agricultural drones.

The pace of agriculture accelerates the remote sensing into the potential market for agricultural drones

So what can UAV remote sensing do for agriculture? In this article, I have consulted the relevant materials to talk about the application value of UAV remote sensing.

1. Monitoring pests and diseases

Pests and diseases are direct factors affecting crop yields and are one of the major agricultural disasters in countries around the world. Large-scale pests and diseases will cause huge losses to agricultural production and the national economy. According to the statistics of the United Nations Food and Agriculture Organization, the world's food production losses due to pests and diseases account for more than 20% of total food production.

The use of remote sensing monitoring technology and the progress of pests and diseases is conducive to the development of governance, timely detection and timely processing, and is also conducive to early prevention and control. The principle is that pests and diseases will cause changes in the pigment, water, nitrogen and other properties of the plant leaf structure, which will cause changes in the reflectance spectrum. Therefore, the reflectance spectrum of the pests and crops and the reflectance spectra of the normal crops from the visible to the thermal infrared bands are significantly different.

In the United States, Australia and other places, remote sensing monitoring with drones is not uncommon. For example, in the United States, there are wheat rust conditions monitored by growers using drones, from which it can be clearly seen where the hardest hit areas are. Some people use drones to view the dodder in the depression (a malignant parasitic weed, mainly parasitic on legumes such as alfalfa, which is susceptible to the serious damage of malignant weeds, often causing the plants to die.) So that early prevention can be achieved before a large-scale disaster.

2. Statistical analysis of plant number and seedling rate

Another use of drone remote sensing mapping is to count the number of plants. UAV statistics are more comprehensive and accurate than manual counting that is time consuming and can only be sampled.

According to reports, in June 2016, cloud-based drone software and graphics solution provider Drone Deploy, agricultural cooperative analysis company Aglytix and agricultural technology company AgriSens collaborated to provide growth analysis tools for crops, through crop quantity statistics, crops The floor area is used to analyze whether the current crop is a good growth distance.

During the plant growing season in 2016, a private farm in northern California invited third-party companies to transplant tens of thousands of tomato plants for 74 acres of farmland. In order to avoid the company not charging strictly according to the number of transplants, private farm staff quickly achieved quantitative statistics using AgriSens' drone application software.

In addition, users can also analyze the seedling rate of newly cultivated plants by means of hardware and software technology of UAV remote sensing mapping to determine the replanting plan.

3. Analyze soil properties

Today, the world's agricultural modernization countries are advocating agriculture. They are required to adjust the input of crops in the process of crop growth according to soil traits, achieve high output with low input, and use various agricultural resources to improve the environment. Good economic and environmental benefits.

As an aerial monitoring technology, agricultural remote sensing is an advantageous means to promote the development of agriculture. Agricultural remote sensing monitoring mainly targets crops and soil. In the visible-near-infrared spectrum of crops, the reflectivity is mainly affected by crop pigment, cell structure and water content, especially in the visible red light band, which has a strong absorption band and strong reflection characteristics in the near-infrared band. It is used for monitoring crop growth, crop quality, crop pests and other aspects. The soil visible-near-infrared spectrum has a relatively low overall reflectivity, and is mainly affected by the coloring components such as soil organic matter and iron oxide in the visible spectrum. Therefore, the inherent reflection spectrum characteristics of soils, crops and other features are the basis of agricultural remote sensing.

In agriculture, there is an important concept called the normalized vegetation index. According to professional explanation, the normalized vegetation index is one of the important parameters reflecting the growth and nutrition information of crops. The calculation method is the sum of the difference between the reflection value of the near-infrared band and the reflection value of the red band. The normalized vegetation index can provide a reference for improving crop health, such as telling you if farmland requires additional fertilization.

Heartland Soil Services, an agricultural services company that specializes in soil samples in the United States, is attempting to combine the Normalized Vegetation Index (NDVI) map of UAV remote sensing mapping with soil sampling analysis to generate a map of soil nutrient elements. This method of combining the two is more detailed than the original soil sampling analysis method (one sample per two acres).

4. Assessment of crop damage after natural disasters

The whole growth and development process of crops is closely related to meteorology. Climate change and severe weather directly affect grain production and farmers' income, which affects the steady and rapid development of agriculture. After inevitable natural disasters, remote sensing techniques can be used to assess damage after storms and freeze disasters.

After the crop is subjected to freezing damage, the chlorophyll activity in the body will be weakened, and the decrease in sensitivity to near-infrared light and red light will cause the vegetation index to change. Therefore, the difference in vegetation index is mainly to judge the disaster situation by the difference of the vegetation index before and after the disaster.

In storm disasters, studies have shown that the reflection of visible light in the vegetation after flooding is enhanced and the near-infrared band is weakened. The combination of near-infrared and thermal bands identifies flooding and healthy cereal crops.

In a strong wind and heavy rain in Illinois, 105 acres (633 acres) of grain in the central part of the state were damaged to varying degrees. UAV service Overhead Ag uses drone technology to generate post-disaster assessment reports detailing minorly damaged areas, moderately damaged and severely damaged areas, and calculating their respective areas and proportions so that farmers can Intuitively understand the damage situation after the disaster.

5. Overview of terraces for easy rectification in a timely manner

Terraced fields are stepped farmland built along the contour line on the slope. It is an important water and soil conservation measure, which has the functions of water retention, soil conservation and fertilizer conservation. As a kind of sloping land management measures, the construction of terraces can change the small terrain of the slope by slowing the slope of the terrain and shortening the length of the slope, so as to effectively control the soil erosion of the sloping farmland. Therefore, timely access to the dynamic indicators of terraces can provide a scientific basis for the evaluation of the effectiveness of terrace construction, prevention of soil erosion, and rational use of water and soil resources.

The use of high-resolution images generated by remote sensing technology to detect soil and water conservation is conducive to the extraction of more detailed soil and water conservation measures. Using the UAV to generate elevation maps, you can visually see the overall layout of the terraces, and facilitate the terrace managers to rectify the terraces and drainage systems in time.

In fact, satellite remote sensing has been developed for a long time, but satellites are susceptible to weather and long orbital periods. In comparison, drones are more flexible and easier to deploy. It is believed that with the further improvement of UAV platforms, sensors and software technologies, future UAVs as a complementary means to other remote sensing platforms such as satellites can help build a more complete monitoring network in agriculture.


(Original title: Agricultural drones can not only detect pesticides but also pests and diseases)