Soil fertility in agricultural crops is vitally important because it ensures good plant growth and development.
Soil is a living medium that contains the nutrients needed by plants for photosynthesis. This is true in all cases, except for soilless crops such as hydroponics, where the nutrients are dissolved in the aqueous solution in which the plants are grown. However, most crops nowadays depend on soil for their development, so it is essential to be aware of the main elements that affect its structure and characteristics in order to obtain the highest level of agricultural productivity in our crops.
- Main factors determining soil fertility
- Phenomena that may affect the process of nutrient absorption from the roots
- Help improve agricultural soil fertility with the BRANDT Reaction range
Main factors determining soil fertility
Now that we have seen what soil fertility is and why it is so important in the agricultural sector, the next step in optimising soil use is to understand the main factors that can affect plant nutrition and, as a result, the yield of our crops.
The main factors that make a soil more or less fertile depend on its texture, structure, organic matter content, pH and cation exchange capacity (CEC).
Although all the factors involved are important, we will focus on those that are easiest to access and alter to improve the yield of our crops: cation exchange capacity and pH. The first refers to the soil’s capacity to retain and release nutrients in the form of positive ions, which is how they are absorbed by the roots, and the second to the amount of free hydrogen ions present in the soil. Soils can be classified as acidic (pH up to 6.5), neutral (pH equal to 7) or alkaline (pH above 7.5).
Phenomena that may affect the process of nutrient absorption from the roots
The availability of nutrients in soil is the result of the interaction of all the components involved in its fertility. Therefore, greater availability will facilitate the photosynthesis process of plants, resulting in higher yield quantity and quality. That is why it is essential to facilitate the greater availability of nutrients in crop soils. But how? Whenever possible, it is advisable to maintain an acidic pH in crop soils, as alkaline soils tend to lead to the insolubility of many of the micro and macro nutrients present in the soil solution, making root absorption impossible. Furthermore, soils with a neutral or alkaline pH are characterised by their low water infiltration capacity. As a result, during rainy seasons they tend to become stagnated, making water absorption difficult during dry seasons.
The soil’s cation exchange capacity (CEC) is the most crucial factor in terms of nutrient availability and, consequently, in soil fertility. A greater CEC usually translates into a higher exchange of nutrients between the soil solution and the plant and is usually associated with increased clays and organic matter. However, not all nutrients present in the soil are available for absorption by the roots, as they may be immobilised (not available for absorption) as a result of their interaction with other ions in the soil. An example of this is the interaction of calcium with other elements such as phosphorus. When calcium and phosphorus are combined, they form calcium phosphate, an insoluble and inactive compound that cannot be accessed by plant roots to obtain the phosphorus they need.
Help improve agricultural soil fertility with the BRANDT Reaction range
BRANDT Reaction was developed to put an end to the different nutrient inhibition phenomena that reduce soil fertility. This range of special fertilisers works by shielding certain nutrients from interactions with other elements present in the environment that inactivate them, making it impossible for them to be assimilated by the roots.
For example, BRANDT® Reaction P DS is designed to protect phosphorus, the second most important macro nutrient for agricultural production after nitrogen. In limestone soils, this nutrient can interact with the large amounts of calcium present in the soil to form tricalcium phosphate, while in acid soils it can form aluminium and iron phosphates. These types of phosphates are difficult for roots to assimilate, decreasing the availability of this nutrient in the soil and negatively affecting soil fertility. However, applying BRANDT® Reaction P DS helps to protect phosphorus ions from these reactions, maintaining a good availability of this nutrient in crop soils.
BRANDT® Reaction K DS and BRANDT® Reaction S DS act in a similar way, protecting potassium and sulphur ions from interactions that may prevent their absorption through the roots in the crop soils to which they are applied.