In the early days of fertigation, fertilizers were applied individually, every two weeks or monthly, based on traditional guidelines for granular product application. This method led to excessive and uncontrolled growth, similar to traditional fertilization techniques.
Solid fertilization is directly linked to high distribution costs in the field and the difficulty of handling small quantities over large areas. In contrast, fertigation does not involve significant operational costs since it does not require labor, and machinery costs are fixed for the season. Additionally, it allows for the uniform distribution of small amounts of fertilizer, which is difficult to achieve with solid fertilizers.
Advantages of fertigation
By distributing the fertilizer in each irrigation cycle, constant nutrition is provided throughout the season, avoiding growth peaks that increase maintenance needs and phytosanitary risks. This method also reduces leaching losses, fertilizer consumption, and the use of large fertilizer injectors.
Fertilizer dosing
Fertigation requires adjusting the fertilizer dosage according to the crop’s nutritional needs and the amount of water used in irrigation. It is essential to ensure that dissolved fertilizers reach the plants without precipitating or becoming immobilized, which depends on the irrigation water鈥檚 pH. A pH between 6.5 and 7.0 is ideal for most crops.
Adjusting dosage according to the season
Fertilizer dosing must be adapted to the crop’s needs during the season, as well as the amount of water used in each irrigation. In periods of lower water allocation, the concentration of the fertilizer should be higher.
The application of products to improve water quality, such as magnesium or calcium salts to control sodicity, should be based on water analysis. In this case, the dosage should not depend on the irrigation volume but on a fixed ratio between irrigation flow and injection flow.
Daily fertigation for uniform growth
To avoid nutritional disorders and maintain uniform growth, the most effective method is to fertigate daily or with each irrigation cycle. This reduces fertilizer consumption, maintenance costs, and phytosanitary risks, without needing high-flow injectors.
Management of tanks and injection equipment
It is recommended to install at least three tanks for the main macronutrients (Nitrogen, Phosphorus, and Potassium), one for micronutrients, and another for the acid used in pH control. Additionally, tanks for phytosanitary products, wetting agents, or calcium can be used, depending on the treatment strategy.
Independent control of each fertilizer
The injection rate of each fertilizer must be adjusted according to the specific needs of each crop and the irrigation volume. It is possible to control each fertilizer independently using dosing pumps or different heads on the same pump, always ensuring that the working pressure of the pumps is higher than the irrigation network pressure.
