Second feature: According to the monthly calculation of income and expenditure records for the month of the total revenue, total expenditure, and the balance of revenue and expenditure categories.

This paper suggests that mining enterprises have to utilize the economic grade which relies on the balance of revenue and expenditure from the view point of maximum utilization of mineral resources.

We can see from the valuation of nutrient balance that the nutrient of revenue and expenditure of each region was nitrogen and phosphorus were surplus, potassium was deficit.