The corn crop is an important commodity in Brazilian agribusiness. One of the biggest costs of farming is the use of fertilizers, either the base fertilization or aerial supplementation, especially nitrogen. In addition to the high cost, the efficiency of the use of this nutrient by the plant is very dependent on the climate and soil conditions. The use of nitrogen fertilization under an application condition that is not optimal is drastically affected, and may not meet the minimum requirement of nitrogen to reach high productive ceilings.
Thinking about strategies to improve fertilization efficiency, also aiming at better root exploration of the plant in the soil in terms of water and nutrients, we can adopt innovative and sustainable technologies, such as the use of biological inputs. There are microorganisms that act as promoters of plant development, helping with crops, ensuring safety, stability and sustainability in agricultural production
Among these microorganisms is the bacterium Azospirillum brasilense, capable of performing nitrogen fixation in grasses. This bacterium assists in the availability of the nutrient for the crop, in addition to acting in the production of phytohormones, which provide the development of the plant, especially the roots. Another key nutrient for maize production is phosphorus, a participant in photosynthesis and energy metabolism of the plant, which can also have its availability optimized by microorganisms. Microorganisms that can help in nutrient availability for the plant, such as Pseudomonas fluorescens, are capable of acting on the phosphorus adhered to soil colloids, making it available for the plant to absorb, via the action of organic acids.
Factors such as biotic (caused by disease and insect attack) and abiotic (environmental variations such as cold, heat, water restriction and salinity) stress can also influence the development of maize cultivation, directly affecting the productivity of production areas.
There are microorganisms that can help the plant by softening the effects of these stresses, as is the case with bacteria of the genus Bacillus. Biological inputs based on these bacteria act to control diseases and can help the plant to mitigate some of these biotic and abiotic stresses. They can act on the root system, protecting it by producing a bacterial biofilm, minimizing entry points for pathogens and helping to retain water in the root system. Furthermore, they can act by producing antibiotic compounds with antifungal, antibacterial, nematicidal. In metabolism, it can provide the plant with metabolites that help in the production of compounds to mitigate abiotic stresses.
There are different ways of using biological inputs in the field, one of them is via seed treatment, performing the application on the day of planting. This practice ensures greater efficiency of microorganisms, especially when dealing with organisms that are more sensitive to environmental conditions, such as Azospirillum brasilense and Pseudomonas fluorescens.
Another way of positioning biological inputs is the use of a jet directed into the planting furrow, a technique that allows optimization of processes, adapting and optimizing the management of producers at the time of sowing.
In addition, we can carry out the aerial application of biological inputs. For this, some precautions are necessary, mainly related to the application mixture, environmental conditions and phenological stage of the crop of interest. When preparing the application solution, the most sensitive microorganisms, such as Azospirillum brasilense, must be used alone, with other biological products or with previously tested nutritional products, not having compatibility with chemical products.
Environmental conditions interfere with the survival of microorganisms before, during and after application, as well as their association with the root system, especially in inoculants formulated with microorganisms of greater sensitivity. The best condition occurs in more humid environments, with lower incidence of UV radiation and mild temperatures. Products based on Bacillus bacteria generally have a greater tolerance to the environment because they have the ability to produce a resistance structure that protects it, the endospore.
The phenological stage of the crop can interfere with the arrival of the microorganism in the soil. It is important that soil-active microorganisms, such as Azospirillum brasilense, Pseudomonas fluorescens and Bacillus sp., get the application as close as possible to the root system of the crop, in order to make the association as quickly as possible. Therefore, in case of positioning these microorganisms in aerial application, this must be done in the initial stages. It is important to emphasize that these microorganisms also act in the aerial part, therefore, it is important to evaluate the purpose of the application for better positioning.
Applying aerially is more susceptible to factors that are difficult to control, such as the weather, standing out as an alternative form of inoculation. This technique can act as a reinforcement, increasing the load of beneficial microorganisms for the crop, or even as a substitute in cases where inoculation via seed or furrow becomes unfeasible.
The use of beneficial microorganisms brings many benefits to the plant and the environment. Bioinputs are products that add to production, being very important tools for corn cultivation, bringing stability and sustainability to the production system. In addition, it also assists in the development and defense of the plant, making it possible to reach high productive ceilings.
Seeking to understand the action of these microorganisms in the field, during the 22/23 corn harvest, the 3tento Specialties team monitored a demand generation area at a producer in the municipality of Cruz Alta/RS. The form of inoculation was carried out via seed treatment at the time of planting. During the evaluations, a better initial development of the plants was observed, with later, greater leaf retention in the lower third and an increase in the size of spikes and number of grain rows. The use of biological management 3tentos (Azospirillum brasilense, Pseudomonas fluorescens and Bacillus sp.) resulted in an increase of 5.0% when compared to the control.
The use of bioinputs brings many benefits to the plant and the environment. They are products that help in the development of the plant through the availability of nutrients, production of phytohormones and in the mitigation of the effects of biotic and abiotic stresses, making it possible to reach high productive ceilings in corn cultivation, bringing greater profitability to the producer associated with a more sustainable management.
