Tomato yields best in medium composition soils, sandy-clayey and clayey-sandy soils, provided they are deep, fertile, well drained and water is available for irrigation. The optimum pH for tomato crop ranges from 5.8 to 7. Light soils are considered ideal for early crops but are usually poor, with low alternative capacity and low water capacity. Tomato is relatively resistant to soil salts and irrigation water. The planning of fertilizer management should always take into account the area, variety, soil, cultivation method and expected production.

Nitrogen has a significant effect on balanced vegetative growth and plant yield. High amounts of nitrogen cause plant hypersensitivity to various pathogens, reduced production due to prolonged flowering and reduced fruit setting, delayed ripening and production of larger fruits with a softer texture. The total nitrogen requirements vary depending on the type of crop (industrial, table tomato, greenhouse tomato) and are within the levels shown in the table below. Of this amount, 30-40% is provided in the basal fertilization through incorporation during soil preparation for crop establishment and the remaining is provided in several individual doses depending on the method of cultivation.

Phosphorus affects germination and plant production, depending on its availability in the soil, soil organic matter content and pH. It contributes to the better development of the root system and the uniform development of the color of the fruit during ripening. However, the high phosphorus content causes uneven coloring of the fruit and quality deterioration (increase of empty spaces inside the fruit). Balanced doses of phosphorus mitigate the negative effects of nitrogen over-fertilization.

Excessive phosphorus fertilization often results in magnesium deficiency due to competition between the two elements. All phosphorus is applied during the basal fertilization at a dosage of 15-22 kg per stremma depending on the type of crop.

Potassium plays an important role in many plant functions. Medium doses of potassium cause increased production of plants with moderate quality fruit in taste and colour. The addition of higher amounts of potassium greatly improves the quality, shape, consistency and uniformity in color of the fruit. Potassium deficiency appears in peripheral chlorosis and necrosis of the leaves, starting from the base leaves, while causes uneven color appearance of the fruit. Almost 50% of the potassium is supplied during basal fertilization and the remaining during surface fertilization, in total amounts of 25-65 kg per stremma.

Magnesium is involved in the function of photosynthesis in leaves, as well as in the synthesis of sugars and carbohydrates. Magnesium deficiency causes a limitation of the plant’s vegetative growth and production as well as peripheral chlorosis of the leaves, from the base to the top. It is added to the basic fertilizer in quantities of 5-12 kg per stremma.

Our Suggestions

Basic fertilisation

Fertilizer type	Dosology
20-10-10+2MgO+0,3B	30-40
20-10-10	30-40
12-12-17+2ΜgO	25-35
15-15-20	25-40
20-10-20	25-35
15-15-15	25-40

Surface fertilisation

Fertilizer type	Dosology
46-0-0	5-10
40-0-0	5-10
34,4-0-0	10-15
33-0-0+31SO3	10-15
27-0-0	10-20
21-0-0	10-20