The aim of every grower is high corn yield, and there are a large number of agronomic factors that can influence this, many of which are within the grower's control, given climatic and soil conditions.
Once a variety has been selected matching the local growing conditions, corn is planted at a density allowing the development of one corn cob per plant. To achieve high corn yields, it is important to maximize the number of grains per cob and to increase the grain weight . Through a balanced crop nutrition program, growers would be able to accomplish this.
Crop Nutrition and Corn Yield
Nitrogen is important in securing high corn yields. It fuels crop growth and development and needs to be readily available.
Phosphorus is particularly important for root development and good crop establishment.
Potassium, like nitrogen, also boosts crop development, and large amounts are taken up by the growing plant. Supplies need to be balanced alongside those of nitrogen. Good potassium nutrition can also help minimize the effects of frost damage and reduces lodging. Potassium is most important for stomatal closure and low supplies result in loss of water from the plant.
Magnesium, sulfur and iron increase photosynthetic activity and maintain good growth for high yields.
Calcium ensures good plant strength, root protection, leaf and stalk production.
Boron is required for pollen tube growth and good grain set.
Zinc is important for photosynthetic activity.
Unavailability of any other micronutrient can also restrict growth processes and subsequent corn yield.
Other crop management practices increasing corn yield
- Maintenance of an optimum soil pH ensures nutrients are readily available and maximizes growth. The preferred pH is in the range of 6 – 7.2 (Measured in water). Corn has poor tolerance of low (<5.0) pH soils when aluminum toxicity reduces root development and manganese toxicity reduces plant development.
- Use of lime to increase soil pH, and gypsum to improve soil structure and calcium saturation, will help increase corn yield. The sulfur from gypsum complexes with free aluminum, reducing the toxicity to the plants.
- Good soil structure is essential for strong root development and good growth – corn is particularly sensitive to soil compaction.
- Spacing, planting density and rotation with other crops help increase corn yield by minimizing disease, pest and weed incidence.
- Weed control is essential to ensure a good, competitive start and pest and disease control will minimize damage to root and productive leaf area. Water supply particularly around silking is important for grain set.