Fertigation involves directly supplying nutrients to plants via the irrigation system, usually in the form of a sprayed liquid. Fertilizer is dissolved in the water used for irrigation, and this method can range from simple watering cans to highly sophisticated and specialized systems for spraying nutrients on plants. It is particularly beneficial to apply fertigation during periods of lower sunlight intensity to avoid leaf burn.

Fertigation is primarily used for rapid nutrient delivery directly to the plants, which is crucial in situations of nutrient deficiency. The main disadvantage is the need for frequent application and the risk of plant damage with excessive use, leading to higher costs. Thus, fertigation should be considered as a supplementary method.

Key considerations in fertigation include:

➤ Composition: Choose a fertigation solution that meets the specific needs of your plants. Different plants may require different nutrients at various growth stages.

➤ Concentration: Use solutions with the appropriate nutrient concentration. Excessive concentration can burn the leaves, while too low will be ineffective.

➤ Weather Conditions: Avoid application on very hot days and in full sunlight, as this can cause leaf burns. Optimal times are early morning or late afternoon when the sunlight is less intense.

➤ Humidity: Optimal conditions include light moisture; avoid application during or immediately before rain.

➤ Uniform Distribution: Ensure that the fertigation system evenly distributes the nutrient solution. This includes ensuring coverage of both the upper and lower surfaces of the leaves.

➤ Nutrient Solution EC (Electrical Conductivity):

EC measures the solution’s ability to conduct electricity, directly related to the amount of dissolved mineral salts, which are essential for plants. Higher EC indicates a higher concentration of mineral salts.

EC does not provide information on the exact chemical composition (e.g., which nutrients are more or less present) but is a quick way to assess overall salt concentration.

Continuous monitoring of EC, especially in soil-less cultivation, is crucial for optimizing plant nutrition, preventing saline stress, and detecting contaminants.

Values of EC are typically expressed in microsiemens per centimeter (µS/cm) or millisiemens per centimeter (mS/cm). The optimal level of EC depends on the type of plants being cultivated, their growth stage, and the characteristics of the water used for fertigation.

If the EC of the solution is too high, it can lead to saline stress in plants. Plants absorb water through osmosis, and a high concentration of salts in the soil solution can hinder this process. In extreme cases, this can lead to dehydration of plants, even if the soil is moist. EC also affects how plants absorb various nutrients. Some nutrients may be absorbed less efficiently in high EC environments, while others may be absorbed in excess, leading to unbalanced nutrition. The optimal level of EC is essential for root health and overall plant growth. Both too low and too high EC can negatively affect root health, directly impacting the health and growth of the entire plant. Different plant species have different levels of tolerance to EC. Some plants may tolerate higher salt levels, while others may be sensitive even to slight increases in EC.

The solution is taken from tanks where fertilizers are dissolved and then applied to the fertigation installation. Ideally, two or three tanks are optimal for a fertigation setup. This is because mixing certain fertilizers can lead to undesirable chemical reactions, such as the precipitation of sediments, which can then clog the fertigation system.