Application of sensors in facility agriculture

Although China is a large agricultural country, it is still a problem worthy of attention to solve the problem of feeding 1.2 billion people. The key to solving this problem lies in improving agricultural production efficiency and enhancing disaster resistance. With the continuous development of science and technology, current facility agriculture (also known as factory agriculture) has become an emerging agricultural industry to solve the above key problems. Facility agriculture is a new agricultural production method that uses greenhouses and their supporting equipment to regulate and control the environmental conditions of crop production. It is an effective means for agriculture to get rid of natural constraints. It is a revolutionary development of conventional agriculture and a high-yield, high-efficiency, high-quality and technology-intensive agriculture. In recent years, foreign countries such as Israel and the Netherlands have reached a very high level in research and production in facility agriculture. In recent years, China's facility agriculture, which is mainly composed of plastic greenhouses and solar greenhouses, is developing rapidly, but compared with foreign countries, it generally has low scientific and technological content, high labor intensity, and low production level and efficiency. Therefore, there is an urgent need for technological improvement to improve the overall level of China's facility agriculture.

To achieve a high level of facility agriculture, information acquisition means is one of the most important key technologies involved in key technologies. Therefore, it is imperative to develop sensors for facility agriculture with high performance-price ratio. As the development direction of sensor technology in the new century, I believe that it is imperative to attach importance to the application of sensors in facility agriculture, which is also one of the important ways to promote the industrialization of sensors. There

are many varieties of sensors used in facility agriculture. According to their detection parameter scores, there are mainly the following types:

(1) Temperature and humidity: The growth of crops is closely related to temperature and humidity. Among the control parameters of plastic greenhouses, temperature and humidity detection and control are one of the main parameters.

(2) Soil dryness: Crop growth requires water. How to irrigate in facility agriculture without affecting crop growth or wasting water resources is a crucial issue. To detect soil dryness, a dryness sensor is needed. The most widely used dryness sensor is composed of a negative pressure sensor and a ceramic filter tube.

(3) CO2: The growth and development of crops cannot be separated from photosynthesis, and photosynthesis is related to CO2, so controlling the concentration of CO2 is beneficial to the growth and development of crops.

(4) Illumination: In facility agriculture, the cultivation management automation system uses artificial light instead of sunlight. Light sensors are used to detect and control the light intensity so that crops can get uniform light.

(5) Soil nutrients: Soil nutrients depend on fertilization. Reasonable fertilization can not only increase crop yields, but also avoid unnecessary losses caused by over-fertilization. The determination of soil nutrients includes the detection of soil organic matter, pH value, nitrogen, phosphorus, potassium, and exchangeable calcium and magnesium. Ion and biosensors are widely used for soil nutrient determination.

Since sensors used in facility agriculture play a role in the system, the performance of the sensors must meet the following requirements:

(1) Good long-term stability The operating environment of sensors used in agricultural facilities is more severe than that of industry, such as high temperature and high humidity. Therefore, the long-term stability of sensors must be higher, and key technologies related to sensor stability, including materials and processes, need to be solved.

(2) Ability to adapt to system requirements The essence of facility agriculture is to achieve artificial regulation and control of crop growth environment conditions, which is achieved through a closed-loop system. Therefore, the performance of sensors should be compatible with the control system. Especially the long-distance placement of sensors, the consistency of sensor sensitivity, the response time of sensors, etc., so that the system can truly achieve rapid response and efficient work of regulating the environment.

(3) Excellent performance-price ratio Due to the large amount of use, it must be low in price, otherwise it will be difficult to promote.

Since China's agricultural modernization level is low and facility agriculture has just started, in order to develop facility agriculture, it is necessary to tap the potential in the sensor production process and reduce costs as much as possible to meet the cost-effectiveness requirements.

I believe that the strategy for the development of this new application field should be to fully mobilize the enthusiasm of sensor manufacturers while preventing a rush and low-level duplication. Therefore, the electronic sensitive industry association should have a unified plan and conduct macro-control to ensure that the development of sensors for facility agriculture is gradual and orderly.

In the "Ninth Five-Year Plan", the "Factory High-Efficiency Agriculture Project" has been included in the national key engineering projects and has been launched. In the 21st century, it will be fully promoted. The sensor technology academic and industrial circles should seize this good opportunity and make the application of sensors in facility agriculture one of the main service areas, which can not only promote the improvement of China's agricultural level, but also promote the development of sensor industrialization itself.