Zinc: the law of the minimum applied

Liebig’s Law of the Minimum states that growth is not controlled by the total amount of resources available, but by the scarcest resource. Although it has many detractors, today it is more valid than ever.

An example of this is what happens with Zinc which is the micronutrient that has deteriorated the most in the past few years. Different studies show us a generalised deficiency in the Pampas region, originated by different causes. In the case of the nuclear zone and high production areas where nutrients have not been restored, the intensification of crops generated the deficiency. As for the western regions of the Pampas, the deficit is caused by natural conditions of a low offer of organic matter, while in Entre Ríos this happens due to the high content of calcium carbonate.

Different studies agree on determining a threshold limit value of 1 ppm in soil analysis of 0 – 20 cm (DTPA method) from which we can find answers to fertilization in most of extensive crops, and not only on grass, where the first trials were initially tested. In addition, yield losses of up to 20% have been documented without detecting any visible causes (hidden deficiency). This is because of the synergy produced when performing a balanced fertilization where Zinc has a leading role in vital process such as Nitrogen metabolism, synthesis of enzymes with meristematic activity and – mainly – in the synthesis of tryptophan, pioneering in growth hormones (for example, auxins).

There are three different nutritional strategies in the market with their variants when it comes to dose this nutrient: foliar treatment, seed treatment and together with the fertilizer at planting. The time of application, the quantities potentially supplied and the possible place of application vary in each of them. This difference constitutes the key to improve the efficiency in the use of this nutrient, which is very static in the soil (similar to phosphorus).

In this respect, the new microgranular resources that combine the offer of a high concentration of Zinc (2%) with the contribution of other essential nutrients (Phosphorus, Nitrogen and Sulphur) constitute an excellent tool to supply this essential nutrient more efficiently when planting to achieve the highest potential of the fertilized crop.