AGRICULTURAL NEWS - Unfortunately, each crop is different because each land is unique. ‘One-size-fits-all’ programmes are always risky.
Each land has its own reserve of nutrients and this must be taken into account when determining a crop’s fertiliser requirement. This is why it’s necessary to have the soil analysed.
Only once you have these results can you determine how to fertilise according to the specific needs of the crop.
The nutrients in the soil are bound in clay colloids and may not be readily available to the plants due to the soil pH or the action of certain minerals. As a result, the nutrients must first be ‘altered’ chemically or biologically before the plants can use them.
Phosphorous, for example, can be in the form of iron phosphate, aluminium phosphate or manganese phosphate. In any of these states, it is unavailable to plants. Fertiliser companies therefore finely grind rock phosphate and treat it chemically.
Applied to a crop, this makes phosphate available to plants. The duration of this availability will depend largely on the soil’s pH.
