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Green corn field in the sunset.

eKonomics News Team

When it comes to crop production, strategy is key. When planning for the growing and harvest season, producers analyze their situation and create a plan that will produce the highest return on their investment. Knowing the required nutrients for their fields, what fertilizers to use, how much to apply, and when to apply are all considerations for growers to think about before planting. Strategizing crop rotation is also a large part of the decision-making process. For growers it is important to know the uptake and nutrient demands of different crops. For example, planting corn after canola can result in nutrient deficiencies leading to poor crop growth and reduced yields.

Corn after canola syndrome

Planting corn after canola can result in phosphorus deficient corn, or commonly known as “corn after canola syndrome”. In early corn development, fungi called mycorrhizae help the crop with roughly 80% of the phosphorus uptake. The mycorrhizae aid in increasing the root volume, allowing the corn to absorb more nutrients much faster. However, canola is not a host of mycorrhizae, so when corn is planted after canola, the fungi must recolonize in the soil from spores since it is not maintained with canola roots. A key indicator of corn after canola syndrome is short, weak and uneven stalks. Corn seedling stalks and leaves may also be purple in color, which is a sign of phosphorus deficiency.

Fixing the phosphorus problem

Growers should test their soil to know exactly what nutrients are available for the next crop. If farmers do plant canola and are considering rotating corn afterwards, they should consider adding phosphorus. If no phosphorus is added to the soil, a phosphorus deficiency can occur in the subsequent corn crop. We recommend applying a starter fertilizer high in phosphorus such as 10-34-0 to assist the plant in the early stages of growth.