Today we are going to treat a crop that is not at all similar to the tomato that we all know, because the fruits are processed to produce the industrial tomato concentrates that we all have canned at home.
The way of growing them is different from the conventional tomato, pests and diseases are also identified differently, etc. We are going to deal with the subject of fertigation and see a fertilizer plan for industry tomato.
The industrial tomato is an extensive crop, typical of the area of Seville, Extremadura and Aragón. All of them with different varieties and productions.
The planting density is usually between 20,000 and 30,000 plants per hectare, achieving a production that ranges between 100 to 200 t / ha.
CHARACTERISTICS OF FERTIGATION IN INDUSTRIAL TOMATOES
When it comes to making a fertilizer plan for industrial tomatoes, the ideal is to have what you have in the soil and what the water provides. We can save (or not) a lot of money in applications of phosphorus, calcium, potassium, etc.
It must be taken into account that the industrial tomato is very demanding in nitrogen , being one of the main elements in this crop.
Above all, because Spanish soils have good potassium reserves, another essential element for the correct ripening of the tomato and the filling of the pulp, but there are times when there is a fault when fertigation and the soil provides the rest.
However, the same is not the case with nitrogen .
NUTRITIONAL LEVELS (%) IN TOMATO LEAVES
When performing a foliar analysis to check the nutritional status of the plant, these are the normal values of each of the elements:
- Nitrogen (N): 3.0-4.0%
- Phosphorus (P): 0.2-0.35%
- Potasio (K): 2.7-3.5%
- Calcium (Ca): 2.0-3.5%
- Magnesio (Mg): -%
- Sulfur (S): 0.2-0.4%
- Iron (Fe): 100-150 ppm
- Manganeso (Mn): 40-350 ppm
- Copper (Cu): 10-20 ppm
- Zinc (Zn): 20-60 ppm
- Boro (B): 21-80 ppm
PROGRAMMING OF THE FERTILIZER IN TOMATO INDUSTRY
To see what we contribute to the soil in fertigation, it is important to see what the crop extracts from the soil , which is translated into the fertilizer units or kilograms of each nutrient it feeds on. Therefore, it is also important to know how to interpret a soil test .
For a production of 100-120 t / ha (there are higher ones), the industrial tomato absorbs the following amounts of the following elements:
- Nitrogen (N): 350 kg / ha
- Phosphorus (P2O5): 140 kg / ha
- Potasio (K2O): 600 kg/ha
- Calcium (CaO): 270 kg / ha
- Magnesium (MgO): 100 kg/ha
However, this is not what we have to contribute as a cover , since the soil is already part of some wealth and we have surely contributed a fund fertilizer.
[alert style = »green»] The normal thing in fertigation is to contribute between 175 and 200 kg / ha of N, 60-70 kg / ha of P2O5, 250-300 kg / ha of K2O and between 20 and 30 kg / ha of CaO. [/ Alert]
These data are pure units, which we will have to transform according to the richness of the fertilizer to be used.
For example. If we want to add all the potassium (250 kg / ha of K2O) with potassium nitrate, the calculations would come out as follows:
Contribution 250 kg / ha of K2O with KNO3 (46% K2O): 250 / 0.46 = 543.47 kg of potassium nitrate to contribute
With this contribution and as potassium nitrate (KNO3) also contributes nitrogen (N = 13%), we would also be applying 70.65 kg / ha of pure nitrogen (or nitrogen fertilizer units) to industrial tomatoes.
NUTRITIONAL NEEDS OF TOMATO
The nutrients must be strategically distributed during the growth of the industrial tomato. At the beginning, it is more demanding in phosphorus as an energy supply and growth effect of roots and absorbent hairs.
Later, it will be necessary to increase that of potassium, bringing constant nitrogen contributions to achieve a strong plant that supports fruit production.
It is advisable not to go overboard because we can have problems in flowering and fruit setting or attract undesirable pests and diseases.
TRANSPLANT TO FLOWERING
At this stage, it is very important that root production is stimulated and that there is a correct establishment of the crop.
Therefore, phosphorus levels must be high, as well as the nitrogen contribution to achieve rapid production of leaves and stems.
[alert style=»yellow»]Equilibrio recomendable: NPK 1-0.3-0.6[/alert]
We will apply 90 kg / ha of N, 30 kg / ha of P and 55-60 kg / ha of K
If we do it with conventional fertilizers (ammonium nitrate, monoammonium phosphate and potassium nitrate), the contribution is as follows:
- Ammonium nitrate: 195 kg
- Monoammonium phosphate : 49 kg / ha
- Potassium nitrate : 130 kg / ha
Ideally, it should be spread evenly across all risks. If, for example, this phase (transplant to flowering) lasts 6 weeks, assuming that it is not paid in the first or second, these values are divided into 6 and it is the weekly contribution.
FLOWERING TO FRUIT FORMATION
In this phase it is important to keep nitrogen constant (not at very high levels), and gradually increase potassium values, in order to favor future ripening, withstand water stress and fill the fruits, increasing their size.
[alert style=»yellow»]Equilibrio recomendable: NPK 1-0.4-2 (0.4 CaO)[/alert]
We will apply 50 kg / ha of N, 20 kg / ha of P, 100 kg / ha of K and 20 kg / ha of Cao
If we apply it with conventional fertilizers (ammonium nitrate, monoammonium phosphate, potassium nitrate and calcium nitrate), so many kg of these elements will be provided:
- Ammonium nitrate: 19 kg
- Monoammonium phosphate: 33 kg
- Potassium nitrate: 217 kg
- Calcium nitrate: 74 kg
If you look at it, the contribution of ammonium nitrate is not that high. This is because the rest of the fertilizers are nitrogen-based and already provide nitrogen, which is why the NH4NO3 contribution is discounted.
FRUIT RIPENING (GIVING MORE IMPORTANCE TO POTASSIUM)
At this stage, with the fruits perfectly formed and already in the phase of color change and maturation, it is interesting to have high levels of potassium to facilitate the transport of photoassimilates (sugars, fatty acids, proteins, etc.) from the leaves and stems to the fruits.
We can see this process of mobilization of nutrients in the following image, where the great importance of potassium in this phase can be seen.
[alert style=»yellow»]Equilibrio recomendable: NPK 1-0-7[/alert]
We will apply 14 kg / ha of N and 100 kg / ha of K.
We can apply it in the following way, being able to substitute any element for others of a different nature, simply by calculating its wealth.
- Potassium nitrate : 217 kg / ha
We do not provide any nitrogen because the needs are already covered with potassium nitrate.
In total, the sum of all these contributions we cover 175-180 kg / ha of nitrogen, 100 kg / ha of phosphorus, 280 kg / ha of potassium and 20 kg / ha of calcium, enough to obtain 100-120 t / ha of industry tomato.