​Efficient nutrition

One of the challenges of Brazilian agriculture is the adoption of sustainable production systems that minimize losses, especially fertilizers, so that maximum economic productivity is compatible with the investments made. In this sense, the efficient use of fertilizers acquires, every day, greater importance in agriculture, due to the rising costs of these inputs, the need to increase productivity and the risks of environmental contamination due to their misuse. Therefore, increasing efficiency in crop fertilization, in their respective production systems, is a highly relevant factor in making the production process more profitable, so that farmers remain in their activities.

It is possible to use cultivars that are capable of increasing the relationship between product and amount of nutrient absorbed, in order to increase fertilization efficiency. However, biotechnology alone is not enough, and it is essential to adopt management practices that increase the efficiency in the use of fertilizers over the years; above all, follow the recommendations of good practices for the efficient use of fertilizers, whether through new practices and/or new fertilizers, as well as the use of the correct product, in the correct dose, at the correct time and in the correct location. Soil analysis is the main tool for determining the correct doses of fertilizers and amendments to be applied to the soil.

In general, the efficiency in the use of fertilizers in Brazil is low. In most cases, the amounts of nutrients applied through fertilizers are greater than those required by crops. In this context, in addition to management techniques, several technological alternatives have been created or improved in order to promote greater efficiency in the use of applied fertilizer. For example, fertilizers coated with sulfur and polymers (PSCU), which have potential capacity to reduce losses, such as the volatilization of ammonia (N-NH₃), which occurs after the application of urea on the surface and on crop residues, reducing the leaching of nitrate (N-NO₃) and potassium (K⁺) for the subsurface layers of the soil, mainly in light soils with high rainfall, in addition to a potential reduction in the volatilization of nitrous oxide (N₂O), a greenhouse gas in the atmosphere with a high heat retention potential, around 300 times greater than CO².

In relation to phosphorus, the technology minimizes the fixation of this element in typical Brazilian soils with high amounts of iron and aluminum oxides. In addition to possible reductions in nutrient loss processes, controlled release fertilizers have the ability to reduce the saline effect, caused to seeds and the root system, and agronomic advantages in several important physiological aspects for plants, in addition to saving labor. of work, machinery and fossil fuel with the use of technology. In this way, the high-performance nutrition provided by this type of fertilizer helps to promote greater efficiency in the use of nutrients and sometimes increased productivity and income for the farmer.

Another important aspect forTo promote greater efficiency in the use of fertilizers is the correct supply of micronutrients to crops. It is known that the name macro and micronutrients indicates the relative concentration of the nutrient in plant tissue and soil, without any biological relevance, since they are all essential for the life of plants.

The supply of micronutrients to plants is influenced by several soil characteristics, such as texture and mineralogy, quantity and quality of organic matter, humidity, pH, redox conditions and interaction between nutrients. Understanding the dynamics of micronutrients in different types of soil and crop requirements, defining doses, sources and micronutrient supply strategies, appropriate to local conditions, are fundamental steps towards greater crop productivity and efficient use of inputs.

In legumes, notably soybeans, the efficiency of nitrogen nutrition, which occurs largely via biological nitrogen fixation, can have its efficiency increased when the needs for fundamental micronutrients for this biological process are met, in which cobalt is responsible for oxygen regulation within the nodule and molybdenum, together with iron, directly participates in nitrogenase. Nickel has a stimulating effect on the nitrification and mineralization of compounds containing organic N and on bacteria of the genus Rhizobium e bradyrhizobium, which contain hydrogenases, for which adequate Ni supply is essential, such that their deficiency can affect N fixation₂ atmospheric. This enzyme is capable of reprocessing part of the H gas₂ generated during the process of fixing atmospheric nitrogen, thus being able to recover part of the energy spent to break the triple bonds that guarantee the stability of nitrogen molecules.

In addition to the supply of these nutrients via seed or foliar, the inoculation of these bacteria must strictly follow the technical recommendation, since when true importance is not given to this procedure, the producer becomes vulnerable to the lack of N supply in his crop, directly impacting in the efficiency of the use of inputs, in the productivity and profitability of the field.

Molybdenum also contributes to the better use of nitrogen applied to different crops, since the low supply of this element within the plant can promote the accumulation of nitrate in the leaf, highlighting the low efficiency in nitrogen assimilation in the absence of this micronutrient.

For an efficient application of micronutrients, it is recommended to observe the source with which you work, in order to achieve total safety in the application of nutrients, without risks of phytotoxicity for the plants and high agronomic efficiency, with ease in the absorption and translocation of nutrients within of the plant, as occurs with 100% chelated foliar nutrition fertilizers.

The adoption of a set of management practices that tend to increase fertilization efficiency is directly linked to productive and economic gains. In this way, the producer will collaborate with increasingly sustainable agriculture.

Click here to read the article in issue 178 of Cultivar Grandes Culturas.