The most common soil problems are:
Long-term use of traditional fertilisers means that fertilisation has not been varied at all and carbon-degrading bacteria groups have gained the upper hand. The consequence is that organic matter, including humus, reduces rapidly. Excessive use of 1 mineral to correct this is even worse; for example, using Mg to stop grass tetany can have major consequences for the absorption of other minerals.
A soil with optimum performance is a balanced soil. The balance between Ca (calcium), Mg (magnesium) and K (potassium) is the most important. Depending on the weight of the soil, a balanced soil has the following ideal composition for the clay-humus complex: