Keys to increasing wheat yield with nitrogen fertilization

The INTA Marcos Juárez team in Córdoba has developed a series of guidelines that can help improve productivity in wheat fields (Illustrative Image Infobae)

As the wheat campaign progresses in Argentina, producers face the challenge of maximizing the yield of their crops. One of the most effective strategies to achieve this is the proper nitrogen fertilizationand key factor that allows to make the most of the nutrients and water stored in the soilIn this context, the team at INTA Marcos Juárez, in Córdoba, has developed a series of guidelines that can help improve productivity in wheat fields, especially those facing adverse weather conditions.

Vicente Gudelj, researcher at INTA Marcos Juárez, explains that The amount of water available in the soil before sowing is a determining factor for the success of wheat cultivation. During the late summer and early fall months, rainfall was recorded that helped recharge the soil profile in some regions, with up to 1.5 meters deep and accumulations of 235 millimeters in plots that came from soybeans and 219 millimeters in those following wheat-soybeans. This water availability is key for the crop to be able to cope with the scarce winter rainfall and await the arrival of the first spring rains.

However, the frosts, which were most intense in July, found the wheat in the tillering stage, which allowed the crop to better withstand the low temperatures. Fertilization, combined with good water management, can make a big difference in yields.

FILE PHOTO: Fertilization, combined with good water management, can make a big difference to yields. REUTERS/Pascal Rossignol/File

One of the most important recommendations of the INTA team is to carry out a pre-planting soil analysis. This tool allows you to accurately determine the nutritional needs of the flock and make informed decisions about the application of fertilizers, particularly nitrogen. It is essential to evaluate the crop conditions and the fertilizations carried out so far to adjust the doses.

Nitrogen fertilization can be carried out at different stages of the wheat cycle.Gudelj points out that, if it is chosen to do so in pre-sowing or during sowing, it is advisable for the planter to incorporate the fertilizer to one side and below the seed for better absorption. In the tillering stage, the application of nitrogen will depend on rainfall so that the fertilizer is correctly incorporated into the soil.

Nitrogen (N), phosphorus (P) and sulfur (S) are key nutrients for wheat. Phosphorus levels should be between 12 and 20 parts per million (ppm), while sulfur should range between 7 and 10 ppm S-SO4. If the soil values ​​are below these ranges, fertilization is necessary. The application of these nutrients should preferably be done before or during sowing, since the plant requires them from the beginning of its growth cycle.

As for nitrogen, the goal is to reach a quantity of 140 to 150 kilos per hectare available between what the soil provides and what is incorporated through fertilization.This figure can vary between 120 and 160 kilos depending on the conditions of each batch.

There are several options for applying nitrogen fertilizer. He use of liquid fertilizers UAN (urea ammonium nitrate solution) is an effective alternative, provided it is applied early during tillering to avoid leaf burn damage and allow foliage recovery. In addition, it is advisable to keep an eye on rainfall forecasts and apply prior to rainfall to maximize the efficiency of the fertilizer.

In the region, a fertilizer that incorporates liquid nitrogen during tilleringapplying it precisely perpendicular to the sowing line. This allows for efficient distribution of the fertilizer without relying entirely on rainfall for its incorporation.

To improve the percentage of protein in the grain, nitrogen can be applied at more advanced stages of the crop cycle, after the flag leaf.In this case, it is preferable to use urea solution (20% NP/P) due to its low toxicity. However, it is crucial not to exceed 20 kilos per hectare, since the crop is very sensitive to phytotoxicity at this stage.

With a year marked by the influence of the La Niña phenomenon and scarce rainfall, water management becomes more crucial than ever. Growers must ensure that the soil has good water recharge in late summer and early fall to sustain wheat growth through the winter.

Gudelj suggests Control weed growth in fallow land to conserve soil water reservesIn addition, if cover crops have been planted, it is advisable to suppress their growth early to ensure that the available water is used by the main crops.

Nitrogen fertilization is a fundamental tool for increasing wheat yields, but it must be applied strategically, considering the specific conditions of each field and the climatic behavior.

Soil analysis, correct application of fertilizers and water management are essential pillars for obtaining good results in this wheat campaign.

Source: Inta