Fertigation techniques and nutrient management in fruit and vegetable cultivation: relevance, benefits and care

Brazil is among the three countries with the largest fruit production in the world, with around 45 million tons per year, and of this total, 65% is consumed domestically, according to data from Embrapa (Brazilian Agricultural Research Corporation). Also according to the agency, the national vegetable market is concentrated in the production of potatoes, tomatoes, watermelon, lettuce, onions and carrots, foods in which family farming is responsible for more than half of national production.

All of these foods have in common a high water requirement, as do most fruits and vegetables, which contain water in their composition. A tomato, for example, is 93,5% water and, during its production process, requires 13 liters of water, which demonstrates the water needs of these crops.

With irrigation, only 1% of the water remains in the plants and the rest that is absorbed is lost through evapotranspiration, an important process for hydration, temperature control and transport of nutrients to the plants. Excess water eliminates nutrients from the roots and harms the plantation. Therefore, adequate knowledge of the characteristics of the soil and the water needs of each crop are important for the efficient use of agricultural irrigation.

With this in mind, one must consider the advantages, as well as the premises, for good fertigation, a technique for applying fertilizers together with irrigation water to nourish the plant and aid in the productivity and quality of the crop.

The benefits of this technique can increase productivity and, consequently, profitability, generate an increase in production quality, optimize resources such as labor, water and fertilizers, in addition to sustainability, since fertigation uses adequate sources of nitrogen (N) which reduces nitrous oxide (N2O) emissions into the atmosphere, generating less environmental impact. 

Various research and experiments on fertigation provide important data regarding increased food productivity. Some comparisons in vegetables reveal gains of 50 to 60% in productivity in leafy crops, such as lettuce, for example. In crops such as tomatoes and cucumbers, the appropriate use of fertigation can bring an increase in productivity of more than 100%.

In addition to the characteristics of the soil and its nutrients, when it comes to fertigation, it is essential to also consider the uniform distribution of irrigation water, without this uniformity the efficiency of fertigation is compromised.

In a newly implemented system, for example, the uniformity of water distribution is around 90%, which is considered excellent, but, over time, the pipes and emitters can become obstructed, causing the amount of water to be reduced. that was foreseen in the initial project is changed. This problem can reduce the uniformity in the distribution of water and, consequently, the nutrients that are applied via fertigation.

When fertigation is adopted in a system with low uniformity, in addition to the risk of some plants suffering from water stress and others from excess, the problem can be exacerbated by the occurrence of nutritional deficiencies, such as the difference in growth of plants from the same plot.

Fertigation is one of the most advanced and efficient methods of applying fertilizers that guarantees nutrition directly to the root zone of the crop throughout the entire growing season. Therefore, for good field fertigation it is important to have good crop planning, correct implementation of the technique, constant monitoring for adjustments whenever necessary and, above all, adequate recommendations on the nutrients needed to fertilize each crop. .