When using a soil improver, there are various criteria to take into account.
As previously mentioned, for each ton of soil improver, there is a certain amount of organic matter added with a given ratio of carbon and nitrogen. These two parameters are crucial but they are not the only factors.
Legally, fertilisers and soil improvers are characterized by three elements: nitrogen, phosphorus and potassium. All three are essential elements. Potassium must also be balanced with magnesium, the K/Mg ratio being fundamental for their assimilation. The product used should be selected according to the plot's needs. If the plot is rich in potassium, there is no need to add more. The addition of potassium should either correct a deficiency or simply maintain the soil's properties.