Know your soil

To make the best of their land and remain financially viable, farmers need to know the potential of their soil. Karabo Puswe, agricultural specialist at FarmSol, explains how this knowledge is gained.

- Karabo Puswe

Each year farmers, financial institutions and investors lose millions of rands because of marginal soils. Farming has become expensive and does not allow room for mistakes.

It is therefore important for farmers to investigate the soil profile and fertility status of each production unit, so that relevant measures can be taken to mitigate the risk of capital loss.

But what is marginal soil? The term is broad, but the simple definition in agricultural context is soil with a limited reservoir of water and nutrients available to plants.

Marginal soil can be categorised by physical characteristics and chemical composition, amongst others.

PHYSICAL CHARACTERISTICS 

The physical characteristics of the soil has to do with rooting depth and soil texture, and whether its content is stony, sandy or clayey.

A farmer can do nothing to change the physical characteristics of the soil, but he or she can work with nature.

Soil depth is one of the key components determining the yield potential of the crop. Maize, for instance, requires a soil depth of more than 1m to reach its maximum yield potential. For this reason, the capacity of land with a shallower depth will already be limited.

The farmer will have to fertilise the soil and choose a cultivar that will optimise the yield potential of the land, or plant crops that are suited for the land, or perhaps avoid planting such fields.

Simply put, a shallow field should never be fertilised and planted with a cultivar that has high yield potential, because the expenses will never be recovered.