Fertigation: Fertilizing through irrigation

Precision in growing methods can be a lifesaver for any growing operation or greenhouse business. Many farmers have experienced the excessive loss of water from using overhead sprinklers. Overhead systems can leave your plants susceptible to disease and pests, which has driven many of today’s farms to implement more efficient irrigation and fertilization systems. Applying nutrients through an irrigation system provides a direct line to the roots of the plant. Because of this, there is a growing popularity of fertigation systems across the agricultural and horticultural industries. There is also an increasing concern from the marketplace to lessen the impact of agricultural production on the environment, and to achieve accuracy and minimize wasted materials, a fertigation system might be the next addition to your greenhouse operation.

Benefits of fertigation
Fertigation is the process of fertilizing crops through an existing irrigation system. Most fertigation set ups use existing drip tape or hydroponic systems to deliver nutrients. Though fertigation techniques can be used in conjunction with foliar sprays or other application methods, an efficient fertigation system can eliminate the need for foliar spraying all together.

There are various benefits many growers find to installing a fertigation system. Integrating a fertigation system can help limit water and nutrient waste for large operations, and it ensures that fertilizer nutrients are available to the root zone of a plant. As opposed to foliar spray, fertigation minimizes fertilizer application rate and increases the efficiency of fertilizer use.

Another major benefit is the avoidance of foliar sprays and the ability to water in the evenings. When using foliar sprays or overhead irrigation systems, water tends to collect on the surface of a plant’s leaves, which if left overnight, can lead to the development of foliar damage or the formation of fungus. Fertigation techniques also reduce fluctuations in soil, fertilizer costs and water waste.

Tips for fertigation
Make sure to use a water soluble fertilizer to avoid blockage and uneven nutrient distribution. A recommended practice is flushing the system after applying nutrients to keep the lines clean and clear of any debris that may cause corrosion or clogging. Different plants have different nutritional needs. It is therefore unwise to apply nutrients at the same constant for all of your crops. Nutrients should be applied very specifically to your plants’ needs and the stage of their life cycle.

When using a fertigation system, growers must compare their readings to their target nutritional values and make adjustments for particular conditions like life cycle, soil type, electrical conductivity of soil, foliar readings and uneven distribution.

When running your irrigation system, do not over-water, as some nutrients, like nitrogen, might leave the favorable area near the roots and leach into the soil. When using fertigation, the uniformity of your nutrient distribution depends on the uniformity of your irrigation system. Consider pipeline length and consistency for an even flow of nutrients throughout your system. Distribution uniformity is crucial to running a successful fertigation system to ensure nutrients are evenly allocated. To measure whether a system is working optimally or not, a grower can measure electrical conductivity to gain insight into the salinity of a solution or check foliar nutrient levels.

For many vegetables, supplying sufficient doses of Nitrogen, Phosphorus Potassium and other trace minerals are essential for ideal plant growth. NPK are considered major builders of proteins, amino acids, chlorophyll and enzymes. Nevertheless, all vegetables are different, some are heavy feeders and some are light feeders. Heavy feeders, like corn and tomatoes, are known to significantly benefit from fertigation systems, because of their high nutrient application needs throughout different parts of the life cycle. While light feeders also benefit from fertigation techniques, the major key here is that you consider different nutritional needs and not over-feed or under-feed your crops or put all the crops on the same plan. Consult with your local extension center to help with specific crop nutritional needs or issues that arise.

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