The Zinc (Zn) is one of the fundamental elements for growth, stress tolerance and the definition of yield components in winter cereals such as wheat. Even so, it is often ignored when planning fertilization strategies.
With the aim of betting more than ever on the innovation in difficult times, Agenda Aapresidthe daily cycle of talks for Argentine agriculture, shared state-of-the-art information on how to manage this micronutrient and enhance the results of the next fine.
Once the management of primary and secondary macronutrients has been covered, such as Nitrogen, Phosphorus, Potassium and even Sulfur in some areas of the Coast, it is essential to pre-sowing diagnosis of micronutrients such as Zinc and Boronstressed Martin Torres Duggan, Senior Consultant of Tecnoagro and teacher UBA.
In the case of Zn, for which the deficient regions are larger, diagnosis is recommended by sampling and soil analysis of the layer of 0 to 20 centimeters to measure the Removable, extractable or disposable zinc. When its levels are located by below 1 part per millionwe are facing a critical deficiencyaccurate.
As important as the chemical diagnosis, it is analyze the physical quality of the soilwhich makes the fertility condition in an integral sense. “The structure of the soil influences the access of the roots to nutrients that move by diffusion and are not very mobile, such as Zn,” he explained.
HOW TO DETECT SHORTCOMINGS
Its deficiency in cultivation can be detected in the leaves as whitish bands between the ribs which can then turn brown with dark edges, “although there may be a limitation on crop development without foliar symptomatology being seen yet”, he clarified.
Due to the numerous functions that this micronutrient fulfills at a physiological and biochemical level, plants with a deficiency usually have smaller sizenumber of macollos y leaf area.
This clearly impacts a lower rate of growth and generation of reproductive structures, and ultimately yield.
The The most important reservoir of micronutrients is organic matter. (MO), Torres Duggan pointed out. For this reason, the first recommendation made by the specialist is to manage production systems that promote good OM accumulation dynamics through various rotationsadding up service cropsand/or using amendments o livestock waste.
This improvement of the soil and the organic pool will naturally provide Zn and other essential micronutrients to the supply of crops.
On the side of the fertilizationsignificant responses are seen when soil values are below the critical limit, he said.
Normally, the doses that are added are usually in the order of 1-1,5 kg Zn/ha to maximize results, for which excellent quality formulations are offered on the market.
TESTS AND RESULTS
Trials in the Pampas region show that in Zn deficient environments the average responses in wheatapplying in total coverage in pre-sowing or in the planting lineare among the 200 and 300 kg/ha.
In post emergencyit can be used to include formulations with Zn in the moments where the UAN is applied, for example, “it is important to guarantee the early availability to achieve the best start of the crop”.
Las foliar applications are also an option, if included as a complement to basic fertilizationhe remarked.
“If Nitrogen is applied to anthesis wheat to improve the protein level of the grain, it is possible to include a formulation with Zn and other products, such as biostimulants, in the combo to enhance the effects.”
Not a minor issue is that a plant with good levels of Zn will have a increased ability to tolerate environmental stress, such as implantation frosts or heat strokes around the critical period. East antioxidant and protective roleextends to the behavior of the plant against pathogens, “making the crop less susceptible to fungal diseases at the root level,” he assured.