Oro Agri: Focus on improving soil fertility

Frank van den Heever, independent soil health consultant, looks at how increasing photosynthesis is an effective step to regenerative agriculture.

In the last century, the adoption of conventional farming practices resulted in agricultural land being severely depleted of components that uphold soil fertility. Regenerative agriculture thus aims to rebuild the carbon content of the soil. This can be achieved by optimising photosynthesis in crops so that ample carbohydrates are produced in the plants. When ample carbohydrates are produced, surplus carbohydrates can be supplied to soil micro-organisms through root exudates. Carbohydrates supplied as root exudates, together with increasing soil micro-organism populations, is potentially the best method for regenerating the soil. Therefore, focusing on regenerating soil fertility and reducing plant stress factors is a logical departure point for regenerative farming.

THE DOMINANT COMPONENT

Soil is a blend of minerals, gases, organic matter, liquids and organisms that together support plant life. The ratios and quantity of various soil components are very important in improving photosynthesis and reducing factors that influence plant stress. 

A well-established root system is a direct indication of effective practices.

The following need to be considered to optimise photosynthesis:

• Soil Nutrition

For optimised photosynthesis, plants need optimised nutrition. The macro- and micro-plant nutrients form part of the mineral component of the soil. The ratio and quantity of these elements are essential. The soil pH is also significant as this affects the availability of these nutrients. Uptake of these nutrients from the soil solution are also influenced by the water content of the soil.

• Minerals and physical condition 

Minerals, soil structure and soil texture can create limitations that can cause stress in crops. Prevalent physical soil limitations include compaction, surface crusting, low infiltration rates and run-off. Oro Agri’s TRANSFORMER^® can alleviate these limitations.

• Aeration

The pore spaces between solid soil components are filled with either water or air. This air is comprised of different gases. Waterlogged soils have poor aeration and low oxygen levels.

The oxygen component is crucial for respiration of roots and micro- organisms. Decreased respiration of plant roots results in reduced water and nutrient uptake. Decreased respiration of micro-organisms will shift the diversity of the microbial population to anaerobic organisms, which are, in many cases, pathogenic to plants. These conditions will reduce photosynthesis.

It is important to maintain an even distribution between spaces filled with water and air. Irrigation management is therefore a key component of this process, but soil structure and texture have a major influence on irrigation management.

TRANSFORMER^® is highly effective in re-establishing an even distribution of water and aeration in the soil.

• Soil solution

The soil solution is the liquid component of the soil and is comprised of water, dissolved nutrients as well as dissolved oxygen. The solution is important for transporting substances within the soil as well as removing substances from the soil. A well buffered and balanced soil solution contains sufficient water, oxygen, and nutrients.

• Organic matter

Organic matter should be effectively composted in the soil. Together with surplus carbohydrate exudates from the plant roots of highly photosynthetic efficient plants, composted organic material increases the soil carbon content significantly.

• Soil organisms

Diversity and quantity of soil micro- organisms are essential factors in regenerative agriculture. Important components in this regard are high soil carbon content, soil moisture, oxygen in the soil, absence of harmful chemicals and good cultivation practices which do not disturb soil structure.

TRANSFORMER^® applications will enhance soil organisms through its positive effect on soil moisture management and aeration of the soil. TRANSFORMER^® SA is a registered trademark of Oro Agri SA (Pty) Ltd (Reg. No 2001/027414/07).

Left: Control | Right: Treated with TRANSFORMER