How to Choose Mineral Fertilizers for Corn

Corn absorbs useful elements from the soil like a sponge. And farmers need to react quickly. Their task is to apply fertilizers in a timely manner and in properly calculated amounts. And precisely those plant foods that corn needs in a specific growth phase.

Fertilizers for corn are selected based on data about the removal of useful elements — per 1 ton of grain, it is necessary:

• nitrogen — 24–30 kg;
• phosphorus (P₂O₅) — 10–12 kg;
• potassium (K₂O) — 25–30 kg;
• sulfur — 3–5 kg.

Mineral fertilizers come in simple and complex forms. Simple ones contain one element, complex ones — several at once. For corn, complex fertilizers are best suited. They provide uniform nutrition, elements are better absorbed, and machinery drives less across the field. This saves resources and time. Sulfur plays a key role. This substance is contained in proteins. The task that sulfur solves is to help corn assimilate nitrogen. If there is not enough sulfur, the leaves will start to yellow, plant development will slow down, and yield will drop by 15-20%. Therefore, the best complex fertilizers are those where sulfur is present in the amount of 7–17%. Such compositions reduce nitrogen losses from leaching and improve grain quality.

How to properly analyze soil before choosing

First, an agrochemical soil analysis is conducted. It is necessary to understand in what quantities the following are present in it:

• potassium;
• sulfur;
• phosphorus;
• what is the pH level (acidity);
• how much humus is present.

If we are talking about black soil rich in useful substances, then fertilizers may be minimal. But if it is sandy or loamy sand soil, then such land is essentially depleted. Therefore, fertilizer norms need to be increased by 30–50%. In a situation where the acidity level is below 5.5, phosphorus and potassium will poorly convert into a form accessible to the plant. Therefore, first, lime or dolomite needs to be added to the soil, and only after that — fertilizers. The analysis shows what exactly is lacking. For example, if phosphorus is low, emphasis is placed on high-phosphorus compositions. If potassium is normal, it can be reduced. Sulfur is checked separately because its deficiency is more common on light soils after rains.

Nutrient needs considering corn growth phases

Corn absorbs useful substances from the soil unevenly. In the 2–6 leaf phase, the plant actively draws phosphorus. It is needed for the development of a powerful root system. Without sufficient phosphorus, roots are weak, the plant holds poorly in the ground and tolerates drought worse. From 6–8 leaves to the appearance of the tassel, maximum nitrogen consumption occurs. Nitrogen is responsible for the growth of leaves and stems. If it is lacking, the plant looks pale, leaves are small, the cob develops slowly. Therefore, the best compound mineral fertilizers with high phosphorus are applied at the start, nitrogen is added in the middle of the season, and potassium and sulfur — under basic application or in complex.

Proven compositions from the assortment of neuron.net.ua

On neuron.net.ua, complex fertilizers from reliable manufacturers are presented. These products dissolve well and keep working over time, key corn’s extended growing season. Key choices include: Polyfoska 6 NPK(S) 6-20-30+7, which packs plenty of potassium and sulfur.  Works well under basic application on fields where potassium and sulfur are lacking.

• Polyfoska 8 NPK(S) 8:24:24+9S — balanced compound fertilizers  for pre-sowing application. Ensures a strong root start and helps the plant survive a cold spring.
• Polyfoska 12 NPK(S) 12:24:12+(22) — universal option with additional sulfur. Suitable average norms on fertile soils.
• Diammofoska NPK 10:26:26 — phosphorus and potassium without nitrogen. Suitable for autumn application or when nitrogen is added separately.
• Diammofoska NPK 9:25:25 — similar composition. Good for basic application crops with high phosphorus and potassium removal.

Such complex minerals ensure stability in plant feeding with useful substances, and minimize the risk of deficiency in certain development phases.

Advantages of sulfur-containing plant food for corn

Sulfur now often becomes a limiting element. In the past, soil got plenty from rain and older plant food. But things are different now. Many fields, especially light ones, experience deficiency. Corn reacts to this quite quickly. Young leaves pale or yellow between the veins.  The plant lags in growth. As a result, the cob forms small, the grain comes out less quality. Fertilizers with sulfur (S or SO₃) solve this problem. They not only replenish the element but also improve nitrogen performance. Nitrogen better converts into protein. Losses from leaching decrease. The grain comes out with higher protein content — this is important feed and food corn. Therefore, in modern conditions, the compound mineral fertilizers for corn are precisely those where sulfur is already in the composition. Such formulas give a stable result even in a dry or rainy year.

How to calculate norms and apply correctly

For a yield of 8–12 t/ha of grain, corn draws N120–180, P60–100, K80–140 kg/ha. On fertile lands, norms are reduced by 20–35%. After legumes, rapeseed, or rich predecessors — even more. The calculation is done like this: how much the plant will take minus what is already in the soil, plus reserve losses (usually 10–20%).

• Basic application: in autumn under plowing or in spring at 250–450 kg/ha of compositions like 7-20-30+S or 8-24-24+9S.
• Top dressing: nitrogen (CAS or ammonium nitrate) in the 6–12 leaf phase at 80–140 kg/ha. If yellowing of young leaves is visible, add complex with sulfur.

Granulated plant food corn with sulfur work evenly and long. It is important to apply to moist soil, embed well, and not use in dry weather without embedding.

Tips on storage and application of fertilizers

Store fertilizers correctly to maintain their potency. Those granules can’t stand moisture. If compositions lie in a damp room, they cake or soak. Then it is hard to scatter them evenly. Therefore, the warehouse should be dry, with good ventilation. Containers are kept tightly closed. It is better to use plant food within the season, not keep them for years. During application, there are also rules. Incompatible compositions cannot be mixed without checking. For example, some high-phosphorus fertilizers combine poorly with calcium forms. Before sowing the application, check the distance from seeds — 5–7 cm minimum. Otherwise, roots will get burns. In wet weather, plant food work better. In dry — mandatory to embed. If applied to the surface, a significant part simply will not reach the roots. Following these simple rules makes application effective and saves money.