1. The Concept and Development Status of Greenhouses
1.1 The Concept of Facility Agriculture
Facility agriculture is a completely different form of agriculture from traditional agriculture. It is a comprehensive agricultural form that applies technology, biotechnology, and environmental technology, enabling modern production and greatly improving agricultural production efficiency. Currently, the automation, mechanization, and intelligent development of facility agriculture is key to ensuring a balanced supply of vegetable and agricultural products in my country and plays an important role in improving residents' living conditions. Compared with traditional agriculture, facility agriculture has significant advantages. Facility agriculture can achieve efficient cultivation and management through the control of facility environmental parameters, resulting in a higher degree of commercialization and intensification. Developing facility agriculture can effectively improve land productivity and resource utilization, and increase the added value of agricultural products. This is also a goal of current agricultural economic development and is of great significance for ensuring the supply of agricultural products and increasing farmers' income levels.
1.2 Development Status of Greenhouses
Greenhouses are one of the main forms of facility agriculture. They alter the growing environment of crops, creating a suitable environment and preventing agricultural products from being affected by external environmental factors and harsh weather, thus increasing the production of agricultural products. Greenhouses are particularly valuable for off-season vegetable supply. They not only promote the intelligentization and standardization of facility agriculture but also facilitate energy conservation and emission reduction, aligning with the low-carbon development concept in modern society and greatly contributing to the development of low-carbon and green agriculture. Currently, greenhouse construction technology in facility agriculture is becoming increasingly mature, with more and more types of greenhouses and superior materials, providing greater support and assistance for agricultural production.
1.3 Types of Greenhouses in Facility Agriculture
Currently, there are four main types of greenhouses, classified primarily according to their architectural style, covering material, and purpose: single-span greenhouses, multi-span greenhouses, plastic greenhouses, and small and medium-sized plastic arched greenhouses. Single-span and multi-span greenhouses are relatively expensive to build and not widely used by individual farmers, but these two types of facilities offer excellent insulation, greatly benefiting crop growth. Conversely, plastic greenhouses and small-to-medium-sized arched sheds have relatively poor insulation, but are cheaper to build and are more widely used in agricultural production. Statistics show that plastic greenhouses account for approximately 63% of all greenhouse applications. There are two main types of covering materials for greenhouses: film greenhouses and PC (polycarbonate) sun panel greenhouses. The former is cheaper and more versatile. PC sun panels are relatively thin, have good light transmission, and excellent impact resistance and fire resistance, but their higher cost limits their application in agricultural production.
2. Development Direction of Greenhouses in Facility Agriculture
2.1 Developing Green Greenhouses
Currently, research on green greenhouses in my country is increasing, but it is still in its initial stage, and many technical issues remain to be resolved. Taking tomato cultivation as an example, greenhouse tomato cultivation should focus on developing planting techniques and strengthening planting management. First, suitable planting sites must be established, meaning greenhouses must be built in suitable locations with ample sunlight. The surrounding environment of the planting site should also be fully considered to achieve localized development. After selecting a suitable planting site, seeds should be selected to ensure excellent quality. Seed disinfection should be performed to improve seedling quality. Fertilizer should primarily consist of farmyard manure, supplemented appropriately with nitrogen, phosphorus, and potassium fertilizers to ensure sufficient nutrition for tomato growth. Furthermore, greenhouse tomato cultivation requires mulching. Therefore, the selection of the film is crucial. A non-toxic and harmless film must be chosen, with good light and air permeability to ensure seedlings receive sufficient sunlight and promote growth. Daily management of greenhouses is also crucial. Maintaining daytime temperatures between 20-30℃ and nighttime temperatures between 15-20℃ ensures fruit quality. To improve vegetable cultivation, the use of chemical fertilizers and pesticides should be minimized during the planting process. This can be achieved by creating a suitable greenhouse environment for vegetable growth and strengthening greenhouse management, such as regular ventilation and installing temperature and humidity control devices to regulate the internal environment. This reduces pests and diseases, promotes healthy crop growth, and ensures green production.
2.2 Developing Intelligent Greenhouses
With the development of internet technology, greenhouses are gradually moving towards intelligent systems. In the future, the level of intelligence in greenhouses can be further enhanced by establishing more intelligent control systems to achieve real-time monitoring of the greenhouse environment. For example, mobile sensor transceivers can be used to monitor crop growth and the greenhouse environment in real time, allowing for continuous monitoring of crop growth. When changes occur in the greenhouse environment, alarm devices can be triggered, and the environment can be adjusted through an information-based intelligent control system. In the design and application of intelligent greenhouses, three key structural layers are involved: a sensing layer to acquire information from within the greenhouse; a network layer to transmit information about crops and the greenhouse environment; and an application layer for data analysis and application, transmitting the analysis results back to the application layer to achieve effective regulation of the greenhouse environment. Currently, some developed countries have achieved automated control of greenhouse environments, with a high degree of automation, enabling automated control of various parameters such as light, moisture, and temperature. Other countries have implemented advanced fully enclosed production systems, where the greenhouse is under closed management, but the internal environment completely simulates the various micro-ecological environments required for crop growth, greatly improving the development level of greenhouse agriculture. my country's facility agriculture started relatively late and is currently undergoing a gradual transformation from traditional manual labor production to intensive and mechanized production.
2.3 Vertical Farming in Green Greenhouses
Vertical farming is a planting method that fully utilizes the space of a greenhouse. In a narrow sense, it refers to the scientific and rational use of intercropping and relay cropping based on the growth characteristics of different crops to complete agricultural production. In a broader sense, it refers to the coexistence of multiple species of crops, thereby achieving full utilization of various production resources. The vertical farming model can also be fully utilized in the development of the greenhouse industry to maximize production efficiency. For example, the "rice-duckweed-fish" mixed farming model is well-suited for the future development of greenhouse facilities. my country has a large population, limited land, and many mountainous areas, leading to uneven distribution of land resources and increasingly strained arable land. Vertical farming can fully utilize the geographical conditions of different regions, improve land utilization, and form more complex multi-layered community structures, creating complex community spaces among crops to achieve increased production and efficiency. Because vertical farming utilizes space vertically, the hardware design must be combined with production requirements. For example, a rotating shelf can be designed inside the greenhouse, with a vertical pipe running through the middle of the spiral staircase. Temperature and humidity sensors can be installed on the pipe to monitor temperature and humidity parameters at all levels. In addition, small holes should be evenly distributed along the pipe, connected to a water supply. Environmental parameters transmitted by sensors can trigger automatic watering; when the humidity in the greenhouse is low, the sensors will activate and water will be poured. Regarding lighting, supplemental lights can be installed every 2 meters along the vertical direction of the pipe, arranged in an alternating pattern to ensure sufficient light, especially for lower-layer crops that require adequate light to grow. The planting order of vegetables can be adjusted according to their different needs; for example, warm-loving vegetables can be placed at the top, and shade-loving vegetables at the bottom.
In conclusion, facility agriculture is the development direction of modern agriculture, which can enhance agricultural resilience and improve agricultural production efficiency. In recent years, with the continuous development of science and technology, the technology of greenhouse facilities has also greatly improved, basically moving from semi-automation towards automation and unmanned operation. Furthermore, greenhouses are being integrated with Internet of Things (IoT) technology, significantly enhancing their level of intelligence. As people's attention to environmental issues and agricultural product quality and safety continues to increase, the construction and development of greenhouses should fully consider the environmental pollution and agricultural product quality and safety problems they may cause. It is essential not only to achieve intelligent construction of greenhouses but also to improve their quality, thus contributing to the development of green and ecological agriculture.
