Here are several reasons why Chen Jiazi can make money by raising ducks now:

1. Improve the land utilization rate: By raising ducks in rice fields, the space and resources in rice fields can be fully utilized and the land utilization rate can be improved. Ducks swimming in water can help clear weeds and pests in rice fields, loosen soil and promote rice growth.

2. Increase crop yield: Ducks in paddy fields can stimulate the growth of rice, promote photosynthesis and nutrient absorption, thus increasing rice yield. At the same time, duck manure can also be used as organic fertilizer to provide nutrition for rice and further increase crop yield.

3. Reduce the pollution of agriculture to the environment: Raising ducks in rice fields can reduce the use of pesticides and fertilizers and reduce the pollution of agriculture to the environment. At the same time, duck activity can improve soil structure and quality, increase soil permeability and water retention, and reduce soil hardening and soil erosion.

4. Improve economic benefits: Raising ducks with aged millet can reduce agricultural production costs, improve crop yield and quality, and improve farmers' economic benefits. At the same time, farming in this way can also increase farmers' employment opportunities and income sources, and promote the development of rural economy.