1000 ml. The function of Kangbida slow-release liquid nitrogen fertilizer is to enhance photosynthesis efficiency, increase chlorophyll content, make the color bright, promote growth, increase protein and amino acid synthesis, and it is rich in nutrition. As of July 20, 2022, liquid nitrogen fertilizer was per mu 1000ml, which was related to crops. For example, an acre of wheat uses 500- 1000 ml.