Each soil type differs with various conditions & there are different types of plants which grow in different types of soil. Why should there be only one standard to determine and decide if the soil has enough nutrients or not?
The soil nutrient values are a general indicator of the soil fertility. Yes, different types of plants grow on various types of soils. However, the soil test report helps the landscape architect in understanding if the soil is deficient in a particular nutrient and whether it can be balanced by adding organic manure or not. Usually the Test Laboratory can help in understanding whether the soil is fit for plantation or not. If you need to understand it more clearly, then we suggest discussing it with an expert.