Why farmers use fertilisers
Plants absorb as many nutrients from the soil as necessary for their normal development. After the end of their life cycle plants decompose, and all the elements go back into the soil.
When using the land for agricultural purposes, humans interfere in the cycle of elements in nature.
Together with the harvest, they take the nutrients that plants have absorbed from the ground, thus breaking the ecosystem balance.
With each harvest, humans remove 60 to 70% more nutrients from the soil than plant residues give back. Over time, the concentration of the most important macronutrients in the soil decreases. This process is called soil depletion.
To retain soil fertility it is necessary to replenish nutrients by returning to the soil at least the same amount. Therefore the modern cycle of agricultural production invariably involves application of mineral fertiliser.
SCHEMATIC OF THE POTASSIUM CYCLE IN SOIL AND AGRICULTURE
SOLI SOLUTION K
VERY SLOWLY AVAILABLE