Cereals are plants of the Poaceae family, normally grown for their grain, a thin-walled fruit attached to the seed, which has unique nutritional values, making cereals one of the world’s major food crops. In addition to their value as a foodstuff, cereals are also used as forage crops, having a dual application in these cases.

Within this group we can differentiate between winter cereals, such as wheat and barley, and spring cereals, such as corn.

Macronutrients in cereals


Nitrogen is the main factor in the growth and development of cereals. It affects the development of crops and the protein content of grain.

Nitrogen deficiency initially causes chlorosis in the oldest leaves, and subsequently inhibits cellular elongation. Prolonged deficiency causes senescence of the old leaves and yellowing of the plant.


Phosphorus acts as a root growth stimulator and encourages flowering, setting and maturation of the grain. Phosphorus deficiencies can cause a plant to darken, or even turn purple in extreme cases. In addition, a lack of phosphorus slows growth and maturation and increases the sensitivity of the crop to stress and disease. Prolonged deficiency causes senescence of the plant’s oldest leaves.


Potassium could be considered a quality factor in cereal crops as it improves resistance to stresses such as drought, frost and disease, plays a part in crop photosynthetic activity and allows increases in grain size and weight. Potassium deficiencies cause yellowing of the oldest leaves with necrosis of the edges and ends, and increase the sensitivity of the crop to various diseases.


Sulphur is considered an essential plant nutrient, since it forms part of the structure of many amino acids, enzymes and cofactors; actively intervening in crop metabolism. Sulphur deficiencies produce effects similar to nitrogen deficiencies, but the effect is first noticeable on new leaves, and may be general in the case of a prolonged deficiency. These effects are usually present from tillering to stem elongation.


Magnesium is important for the correct development of your crop, since apart from playing an active part in the formation of various proteins, it constitutes the centre of the chlorophyll molecule, and is also indispensable for the photosynthetic functions of the plant. Magnesium deficiencies produce intervenal chlorosis on the leaves, along with chlorotic stains. It is a common deficiency in soils with a very low pH, or ones which experience flooding or low temperatures.


Calcium is essential for the stability and formation of the plant cell wall, which makes it indispensable for the proper development of all the structures of the crop.

Calcium deficiencies wither the edges of new leaves, altering their normal shape while weakening the crop’s root structure.

Micronutrients in cereals


Manganese, despite being needed by crops in small doses only, is essential as it is the key to many of the crop’s metabolic processes: Synthesis of chlorophyll, vitamins and amino acids; assimilation of nitrates and CO2, hormonal and cell division activation, and other metabolic reactions such as cell respiration and water photolysis. Manganese deficiencies cause yellowing of new leaves and the appearance of whitish veins. Although it is not a common deficiency in this type of crop, it is a very pH-dependent micronutrient, and deficiencies can occur at very basic pH levels .


Copper is equally important despite the small doses required by the crop, as it is part of the structure of many proteins and enzymes, as well as chlorophyll which is essential for photosynthesis. It also plays a part in regulating plant transpiration, being indispensable for the water regulation of the crop.

Copper deficiencies cause yellowing of the ends of new leaves and deformation of the ears.


Zinc is involved in many processes which are essential for effective plant development: metabolism of carbohydrates, proteins and auxins; formation of pollen, resistance to certain pathogens and stability of cell membranes. Zinc deficiencies lead to leaf necrosis and delayed crop growth as well as increased susceptibility to stress.


Iron is fundamental to chlorophyll synthesis, maintains the structure of chloroplasts, and plays a part in the enzymatic activity and, therefore, the metabolism of the plant.

Iron deficiencies cause yellowing of new leaves. Although such deficiencies are rare in these crops, they can occur in certain areas with, for example, high rainfall or calcareous soils.


Boron, after zinc, is considered one of the most important micronutrients for crops: it is involved in the formation of reproductive structures, as well as protein synthesis and transport of sugars by the plant. In addition, it plays a part in the formation and stability of the cell wall, actively participating in both apical and stem development processes.

Boron deficiencies lead to deformation of stems and leaves, as well as a reduction in fruit content and quality.

Don't miss anything

Subscribe to
our newsletter

Newsletter Herogra Especiales

Get highlights of the most important news delivered to your email inbox

    I read and accept privacy Policy