Corn Nutrition: Keys to Maximum Yield

By Agr. Eng. MSc. Cecilia Cerliani - Faculty of Agronomy and Veterinary Medicine, National University of Río Cuarto.

Nutritional management of corn is essential to achieve the maximum yields the site allows. During early or first planting periods in central Argentina, the yield-determining period occurs between late December and early January, when solar radiation is at its peak .

In these scenarios, and as long as water isn't a limiting factor, yield will depend on the crop's ability to intercept and utilize this radiation. Therefore, ensuring optimal nutritional status from the start is essential to avoid restricting growth.

In early-planted corn, the crop establishes itself at temperatures well below optimal , which reduces its initial growth and development. Under these conditions, having nutrients available from the outset is key to achieving vigorous plants that absorb a greater amount of resources . A good starting point for designing a fertilization strategy is soil analysis, an essential tool for diagnosing the availability of essential nutrients.

Among the priority nutrients for planting, phosphorus (P) and zinc (Zn) play crucial roles in early plant growth . Soil levels below 15–18 ppm for P and 1 ppm for Zn can limit potential yield, making fertilization necessary. Due to their low mobility, it is recommended to place them preferably below and to the side of the seed, so that they are quickly intercepted by the roots.

In recent years, symptoms of sulfur deficiency have been observed even in fertilized plots , suggesting a review of traditionally used dosages. Boron is also increasingly appearing below the critical threshold in soil analyses , which coincides with the observation of deficiency symptoms in plants. While there are several commercial sources for its application, further research is still needed to define the best management strategies for this nutrient.

Nitrogen is the critical "nutrient" for determining yield , especially under high-potential conditions, as would occur at early dates. Regional models are currently available that allow for estimating the optimal dosage based on expected yield, soil mineralization, and climatic conditions. It is key to adjust the timing of application and the nitrogen source to the specific environmental characteristics of each site, always seeking to maximize efficiency and minimize losses.

Positive responses to the application of other nutrients such as magnesium, potassium, and calcium are also being reported in certain environments . Although these are isolated situations, this highlights the importance of not excluding these elements from the initial diagnosis, as they could become limiting factors in the future.

Furthermore, the development of biological products applied to corn nutrition opens up new opportunities . They can be a good tool to complement chemical fertilization and improve nutrient uptake efficiency.

In short, an effective nutritional strategy for early corn should begin with a comprehensive field assessment, prioritize early availability of key nutrients such as phosphorus and zinc, adjust nitrogen doses based on the environment and yield expectations, and monitor for potential emerging deficiencies.

The complementary use of biological products, along with tailored management for each situation, will allow us to move toward more efficient, sustainable, and profitable production systems.