The Potash Development Association (PDA) has published trends identified within a 2022/23 survey of UK soil potassium index values.
The work was carried out by the Professional Agricultural Analysis Group (PAAG) and its full report is now available on the association’s website.
Potassium (K) is a vital nutrient for plant growth, and its availability in soil plays a critical role in agricultural productivity across all cropping and grassland-based enterprises.
The PAAG analysis revealed that only 29% of all soil samples were at the target K Index (2-), while 33% were below target and 37% were above target. ​
Arable soils showed better potassium levels, with 31% of samples at target. In contrast, grassland soils lagged behind, with only 26% of samples at target. ​
Alarmingly, 39% of grassland samples were below the target K Index, indicating widespread potassium deficiencies. ​
Over the years, the percentage of samples at the target K Index (2-) has remained stable at around 30%. ​However, arable soils have shown a steady improvement in potassium levels, with mean K levels increasing since 2000. ​
In 2022/23, arable soils reached a mean K level of 189 mg/L, reflecting better nutrient management practices. Grassland soils, on the other hand, have remained relatively stable, with mean K levels hovering around 165-170mg/L. ​
Grassland soils potassium levels
​The PAAG data highlights a stark contrast between grassland and arable soils, with grassland soils consistently showing lower potassium levels compared to arable soils. ​
This disparity underscores the need for targeted interventions to address potassium deficiencies in grassland areas. ​
The overall findings of the PAAG work emphasise the importance of regular soil analysis to guide fertiliser use and address nutrient imbalances. ​
Grassland soils, in particular, require focused attention to improve potassium levels and ensure sustainable agricultural productivity. ​
While arable soils have shown progress in potassium management, grassland soils continue to face significant challenges. ​
According to the PDA, addressing these deficiencies through informed nutrient management practices is crucial for enhancing soil health and agricultural output across the UK.
PAAG was established in the UK in 2009 to help ensure a common quality standard amongst participating laboratories and to promote the benefits of soil analysis for efficient nutrient management.
One of the early actions agreed by the PAAG was the collation of their UK soil analytical data and publication to show breakdown by soil pH class and by phosphorous, potassium and magnesium indices.
