Tracing best elements
Aim for a balanced supply of each nutrient at growing to prevent drops in yield
Trace elements have a vital role to play in the production of high-yielding cereal crops on an annual basis. Cereal crops have higher requirements for major nutrients such as nitrogen (N), phosphorus (P) and potassium (K).
These nutrients are usually required at kilogrammes per hectare rates, whereas trace elements are normally required in grams per hectare rates. It is critical that there is a balanced supply of each nutrient throughout the growing season as temporary shortage at critical times of the year can result in a yield reduction.
In this article, I will discuss the main trace element deficiencies affecting winter and spring cereal crops in Ireland.
Manganese (Mn) deficiency is one of the most encountered trace element deficiencies in both winter and spring cereal crops. Deficiencies tend to be due to low soil Mn availability for crop uptake rather than an absolute deficiency in the soil. Manganese is essential in the early stages of crop development, especially in root and tiller development. Crops with sufficient levels of Mn tend to be less prone to take-all infection.
There are several soil conditions that reduce the availability of soil Mn, including:
- Recently limed or over-limed soils;
- High soil organic matter or peaty soils;
- Poorly consolidated or puffy seedbeds;
- Light/sandy, well-drained soils with a pH greater than 7.0.
In addition, other seasonal and weather factors can play a part, such as low soil temperatures plus wet/dry soil conditions that may reduce soil Mn availability and aggravate a Mn deficiency on a wide range of soils (in the early stages of crop development).
Mn deficiency is easily detected, as it can be associated with parts of a field where there will be patches of pale yellow, floppy plant growth. The younger foliage is first affected, turning a pale green colour.