The long-term development and sustainability of the NPK fertilizer production line involves many aspects, including technological progress, resource management, environmental protection measures and market demand. Here are some key factors and strategies:

1. Technological progress: The introduction of advanced automation and intelligent technology to improve production efficiency and product quality. Continuous improvement of the production process, improve the ratio of fertilizer precision and production stability. Regular update and maintenance of organic fertilizer equipment, the use of energy-saving and efficient production equipment to extend the service life of equipment.

2. Resource management: Ensure the stable supply and high quality of raw materials, establish a stable supply chain and long-term cooperation. Adopt energy-saving technologies and renewable energy to reduce production costs and energy consumption.

3. Environmental protection measures: Install efficient waste gas and waste water treatment systems to reduce environmental pollution in the production process. Promote green production concepts, reduce the negative impact of production on the environment, and comply with environmental regulations and standards.

4. Market demand: Conduct regular market research to understand the changes and trends of market demand, adjust production strategy and product positioning.

5. Training and management: Regularly train employees to improve their skills and production operation level to ensure the stable operation of the production line. Establish a sound quality management system to ensure that products meet quality standards and customer requirements.

6. Continuous improvement: Establish a sound quality control system, regularly check and evaluate product quality, find and solve problems. Based on market feedback and production data, continuously optimize the production process and management measures to continuously improve the overall efficiency of the production line.