帮我翻译一点资料。（翻译成英语）

Fertilizing the soil in northern China there is imbalance in fertilizer application, the distribution of unreasonable, do not pay attention to scientific fertilization, the proportion of non-conforming fertilizer nutrients, fertilizers, varieties of structure is irrational, improper fertilization, the decline in the proportion of organic fertilizer problem. This will certainly have the physical and chemical properties of soil are affected, especially in soil nutrient status will change a lot, thereby affecting the normal growth and development of plants. Of certain broad-leaved species of leaf mineral nutrient analysis conducted to determine their nutritional status, has become a broad-leaved species to improve the nutritional environment and the key application is to improve the quality of the species one of the important ways.
In this paper, in Shenyang City for five tree nurseries and the ratio of nutrient elements, select the down elm leaves, which are nitrogen, phosphorus,