The main reasons why organic fertilizer production lines attract investment from customers are as follows:

1. Environmental protection trend: With the increasing awareness of environmental protection, organic fertilizer is gradually receiving attention as a sustainable agricultural input. Many countries and regions are promoting the development of organic agriculture, which provides a broad market space for organic fertilizer production lines.

2. Resource recycling: Organic fertilizer production lines usually use agricultural waste, livestock and poultry manure and other raw materials, which can effectively reduce environmental pollution and realize the recycling of resources. This model is consistent with the concept of sustainable development.

3. Market demand: With the increase of consumers' attention to healthy food, the market demand for organic products is growing. This directly drives the demand for organic fertilizers, thus attracting investment.

4. Policy support: Many countries and regions have introduced policies to support the development of organic agriculture and ecological agriculture, which provides a good policy environment for investment in organic fertilizer production lines.

5. Technological progress: In recent years, organic fertilizer equipment technology has been continuously developed, improving production efficiency and product quality, and reducing production costs. This makes the return on investment of the organic fertilizer production line relatively high.

6. Diversified operation: Investment in organic fertilizer production lines can be combined with other agricultural projects, such as organic planting, breeding, etc., to form a complete industrial chain and improve the overall economic benefits.

To sum up, the organic fertilizer production line not only conforms to the trend of environmental protection and sustainable development of today's society, but also has a good market prospect and investment return, so it has attracted the attention and investment of many customers.