Fertilization needs during cultivation

Each type of crop has different nutritional needs. In an organic garden, especially with local varieties, it is important to know the fertilization needs during cultivation to avoid overloading the soil and promote healthy and balanced production.

Below, we detail the main needs according to the most common vegetable groups:

🥬 Leafy vegetables (lettuce, spinach, cabbage...)

Main nutrient: Nitrogen (N)

Soil preparation: Add mature compost or a little well-rotted manure.
During cultivation: If necessary, apply worm castings diluted with water (1:10) every 10–15 days.
Council: If the leaves turn yellow or growth slows down, it may be lacking nitrogen.

🍅 Fruit vegetables (tomato, pepper, eggplant, zucchini...)

Main nutrients: Phosphorus (P) i potassium (K) – moderate nitrogen at the beginning

Soil preparation: Mature compost with a little wood ash or well-decomposed sheep/cow manure.
During flowering and fruiting: Light contributions of ash (well diluted).
Avoid: Excess nitrogen once they start to flower, as it favors more leaves than fruit.

🥕 Roots and tubers (carrots, radishes…)

Main nutrients: Phosphorus and potassium, low in nitrogen

Soil preparation: Very mature compost, without fresh manure.
During cultivation: Normally it is not necessary to add anything if the soil is fertile.
Council: Too much nitrogen can deform the roots or cause too many leaves to grow.

🌱 Legumes (beans, peas, kidney beans...)

Key nutrient: They don't need much nitrogen, since the they fixed in the air

Soil preparation: Light compost or none if the soil is rich.
During cultivation: They can benefit from phosphorus (ash).
Council: Once harvested, leave the roots in the soil: they provide nitrogen for the next crop.

📌 How to know if you need to fertilize?

Warning sign:

Yellow leaves → lack of nitrogen
Small fruits or lack of flowering → lack of phosphorus or potassium
Slow growth or weak plants → possible general deficiency

Remember: The best fertilizer is living soil. Observe it, touch it, and see how the plants respond.

🌾 General recommendations

Well made compost as the basis of all planting work.
Manure only if it is well composted and in small quantities.
Worm compost as a nutritional booster during cultivation, diluted with water.
Wood ash as a natural source of potassium (in small quantities and well watered).
Crop rotation to avoid soil erosion and maintain its fertility.