Corn Culture: What is the best fertilizer for planting in Cerrado soils?

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The corn crop was one of the most researched in the past regarding the use of fertilizers, mainly with NPK fertilizer, that is, nitrogen, phosphate and potassium fertilizers. 

Its use was made for several reasons, but mainly because it is a widely used crop and highly responsive to fertilization. Currently, these studies regarding the nutritional demands of corn and its absorption rates are often outdated, as they were developed with varieties that are no longer commercialized, have low productive potential and are recommended mainly for the South and Southeast regions of Brazil.

Given technological advances, especially genetic improvement, which has provided varieties with high production ceilings and, consequently, greater nutritional requirements, combined with cultivation in the Center-West, North and Northeast regions, under Cerrado conditions, a question arises: Is the corn being fertilized correctly in this ecosystem?

Let's explore more about the topic. Good reading!

Efficiency of fertilizers for corn crops in Brazil

First of all, it is I need to know the soil and climate conditions of the Cerrado to ensure the quality and efficiency of the use and management of corn fertilizer. 

The Cerrado is the second largest Brazilian biome, representing approximately 22% of the national territory.

It has a seasonal tropical climate with a dry and rainy season and high temperatures throughout the year. The predominant soils have low natural chemical fertility and high acidity. On the other hand, they are deep soils, with high physical quality, flat and gently undulating relief. 

To provide the quantities of nutrients required by corn varieties, it is necessary to carry out a liming program to correct soil pH and fertilize. 

To be successful in fertilizing na corn culture, one must consider the amounts of nutrients present in the soil and what the plant extracts. 

Several studies are being carried out with the aim of generating specific interpretation and recommendation manuals for each microregion of this biome, taking into account their particularities. However, the existing manual aimed at Cerrado soils is still recommended.

Doing the calculations

A total extraction of nutrients by corn crops during the production process will depend on the estimated productivity and the accumulation of these nutrients in the vegetative and reproductive structures and in the grains that will be harvested. For example, to produce 1 ton of corn, 80,5 kg of nitrogen (N), 8,7 kg of phosphorus (P) and 31,8 kg of potassium (K) will be needed, according to an average of studies. 

But remember that extraction and export are different denominations, that is, extraction refers to the total amount that the plant absorbs of a certain nutrient from the soil during its life cycle, while export refers only to the amount of nutrient that Soil will be removed from the system from the harvested product. 

It is observed that nitrogen and potassium are the nutrients that corn requires in greater quantities.

Fertilizers for types of corn

Among the sources of nitrogen, urea [CO(NH2)2] is the fertilizer most used by corn producers. This fact corresponds to the lower cost of this fertilizer and greater guarantee of nitrogen, around 45% of N. However, urea is susceptible to losses due to ammonia volatilization, a chemical process that occurs in the soil from the urease enzyme. 

The greatest losses of N through volatilization occur when urea is applied as cover, without incorporation into the soil, being exposed to high temperatures, winds and humidity. 

The use of urea with the iNBPT urease inhibitor (N-(n-butyl) thiophosphoric triamide) significantly reduces N volatilization, promoting greater efficiency of nitrogen fertilization in top dressing, becoming an attractive alternative for the producer.  

Studies carried out in Cerrado conditions in the states of Piauí and Pará demonstrated that the application of 180 kg/ha of nitrogen top dressing at the V4 stage provided maximum productivity of summer corn grains, approximately 175 sc/ha. In another research carried out in the Cerrado in the south of Maranhão, a higher productivity of summer corn (198 sc/ha) with 120 kg/ha of nitrogen was observed - it is worth highlighting that in this last work the area was under planting, which possibly favored the use of nitrogen doses, rationalization of costs and increased productivity. 

In relation to potassium, some factors can reduce its availability to plants, including its low concentration in the soil, lack of replacement through fertilization programs and incorrect management of potassium fertilizers. ANDThese conditions can lead to a shortage of this nutrient in the plant due to leaching. 

Potassium has high mobility when present in soil, especially those that have low cation exchange capacity (CTC), high infiltration, sandy texture and high rainfall, typical characteristics of Quartzarene Neosols and Dystrophic Oxisols, soils present in the Cerrado. 

Potassium losses in Cerrado soils vary between 35% and 48% of the total applied. In general, the recommendation for potassium application should be broadcast to sandy soils, however studies have indicated that the leaching of this nutrient increases from the medium texture with doses above 80 kg/ha of K2O per year, regardless of the method of application.

Already match, a quantity greater than that required by the plant is often recommended, due to the high fixation of this nutrient to soil colloids. Tropical soils have low availability of phosphorus for the plant and high fixation of this macronutrient on the clay surface. 

In this case, it is essential to fertilize the corn with phosphate sources with high solubility, as this will contribute to greater efficiency in the fertilization program. 

Fertilizer application methods for corn cultivation in Brazil

Research results demonstrated that the application method located in the corn planting furrow provided the highest grain yields of this crop in Cerrado conditions, mainly in new cultivation areas. Considering that the plant absorbs phosphorus in the form of diffusion via the roots, that is, the proximity of the fertilizer to the root system is the key to success in absorbing this nutrient into the soil. 

As phosphate fertilization is maintained, combined with management that contributes to restoring the chemical fertility of the soil, after the increase in phosphorus levels in the soil, it becomes possible to broadcast phosphorus. 

The amount of match to be applied will vary according to soil content and corn extraction according to expected productivity.

In this scenario, conservation practices, such as soil cover, crop rotation, minimal soil disturbance, intercropping of corn and forage grasses, crop-livestock integration, among others, must be used to guarantee the maintenance and increase of organic matter. 

To achieve efficient corn fertilization, with greater use of nutrients by plants and high productivity, always seek interpretations and recommendations from regionalized technical bulletins, often originating from research institutions in your locality that are recent studies. 

Conclusion

Remember that corn fertilizer recommendations are not a cake recipe and can be copied from one region of the country to another. Professional guidance is a great ally for making assertive decisions, in addition to choosing fertilizers with a high technological level, they have already proven productive increases in corn cultivation in Cerrado soils. 

Faced with all these characteristics and challenges of soil fertility and mineral nutrition of corn crops in the Cerrado, Mosaic Fertilizers has the product Performa Plus. 

A multinutrient fertilizer combined with Mosaic's exclusive technologies, with the aim of completely and efficiently meeting the main nutritional demands of corn crops, whether in summer or off-season cultivation. From the supply of nitrogen in ammoniacal form, without risk of losses due to volatilization, high solubility phosphorus, superior potassium efficiency and two forms of sulfur and boron to cover the entire corn crop cycle. 

In addition to the high physical quality of the fertilizer granules, which provides uniform distribution in your crop, increasing operational performance and increasing productivity.

To learn more about the subject and also learn more about Mosaic Fertilizers’ high-tech products, visit: nutricaodesafras.com.br.

Dr. Zieglenristen Calabria

Market Development Specialist at Mosaic Fertilizers

References

National Supply Company -CONAB. Perspectives for Agriculture - 2021/22 Harvest – Grains Edition. Brasília: CONAB, 2021. vol. 9, 85 p. Available in: https://www.conab.gov.br/institucional/publicacoes/perspectivas-para-a-agropecuaria/item/16668-perspectivas-para-a-agropecuaria-volume-9-safra-2021-2022-edicao-graos. Accessed on: January 13, 2022.

MELO, F. B.; BASTOS, E. A.; CARDOSO, M.J.; ANDRADE JUNIOR, A. S. Nitrogen and potassium fertilization and technical and economic productivity of corn cultivated in the Cerrado of the eastern region of Maranhão. Research and Development Bulletin 130, Teresina: Embrapa Meio-Norte, 2021.