Farm Management

Building soil fertility

Soil fertility is a function of its abundance, structure and biological activity. Soil cannot be treated as a neutral substrate; it is a living and variable entity. Therefore, fertility can be built up, or it can be impaired or destroyed.

Improving fertility is a long-term process, based on crop diversification, increasing humus content, stimulating microbial activity, caring for soil structure and water management. Therefore, the basis for building soil fertility is a proper, building crop rotation (if there are no conditions for crop rotation in a classic crop rotation), enabling the soil to increase its biological activity. This is also helped by leaving as much crop residue as possible and using organic fertilisers. Too much mixing and oxygenation of the soil is detrimental to soil fertility, as is the use of excessive quantities of fertilisers, especially nitrogen fertilisers, as it accelerates the “burning” of organic matter and increases carbon dioxide emissions into the atmosphere.

When deciding to grow any crop, it is important to establish beforehand whether the soil contains sufficient nutrients and whether its pH agrees with the requirements of the planned crop. Soil testing is necessary at least every four years, and the results should be used to calculate the necessary fertilisation of the soil and plants. It is optimal to test the soil every year, once uniform soil zones and the correct number and location of samples have been defined. The results should be used for appropriately differentiated, precise mineral fertilisation to make up for soil deficiencies.

The soil pH value is a decisive factor for the availability of many plant nutrients, the activity of soil organisms and indirectly the soil structure. Too low a pH leads to an increase in the presence of Al+3 ions in the soil, which are toxic and impair plant growth and yield, as do many metabolic products in acidified soil . Fertilisers that change pH are mainly calcium or calcium-magnesium fertilisers, depending on the chemical form, which act quickly (oxide) or slowly (carbonate, dolomite). A rapid change in pH with large doses of oxide fertilisers is detrimental to soil biology and is also very risky for crops. Small changes in pH with slow-acting fertilisers are best for soil fertility. Both the judicious use of mineral fertilisers, pH regulation, the use of crop rotation and the minimisation of excessive soil movement and oxygenation contribute to promoting the biodiversity in the soil that determines sustainable fertility.