Autumn is the time to tackle potassium deficiency in silage fields
Spring is usually the time of year when soil sample results appear on advisors' desks across the country and farmers start looking for advice on the appropriate fertiliser to spread.
Approximately 60pc of our soils nationally are at index 1 and 2 for potassium.
This means that six out of 10 silage fields are deficient in potassium, and this poses a challenge. Autumn time is the ideal time of year to rectify potassium deficiencies.
So why is potassium such an important fertiliser? Potassium is the nutrient taken up in the greatest quantity by grassland swards and has a wide-ranging role in the plant, affecting nutrient uptake, photosynthesis, rate of growth and feed value.
It is particularly important for increasing stem strength, improving drought resistance and cold tolerance, and importantly for increasing yield.
Potassium fertilisation is vital, especially in autumn and on older grass. If adequate amounts of potassium are not available, the rate of growth and yield will be restricted.
There is also a relationship between nitrogen and potassium, as the response of grass to nitrogen is dependent on an available supply of potassium to allow N uptake as nitrate and conversion into proteins.
In silage fields in particular, stem strength is of huge importance. Silage crops low in potassium are more prone to lodging, as the stem cannot hold up the seed head and grass plant.