Wholly K

Wholly K – A forgotten nutrient

When it comes to crop nutrition, Potassium (K) is often underestimated, but it’s one of the most essential elements for supporting plant growth, resilience, and productivity. Think of Potassium as the fuel that powers the nitrogen-built engine of your crops.

At every stage of the plant’s journey, from vegetative growth to reproductive development, choosing the right form and amount of potassium is key to ensuring performance under pressure.

Why potassium matters

  • Mobility and regulation: Potassium facilitates the movement of water, nutrients, and carbohydrates throughout the plant. It plays a critical role in regulating the uptake of Calcium (Ca), Nitrogen (N), and Sodium (Na).
  • Stress tolerance: It enhances the plant’s tolerance to abiotic stress, including drought, temperature extremes, and nutrient imbalances.
  • Photosynthesis and energy storage: Potassium supports photosynthesis, sugar production, storage carbohydrate formation, and even oil synthesis.
  • Water use efficiency: By influencing stomatal function, potassium improves how efficiently plants use water.
  • Protein synthesis and nitrogen use: K is involved in multiple stages of protein synthesis and is essential for maximising Nitrogen Use Efficiency (NUE).
The response over untreated for Wholly K in Winter Wheat 2018-2019

K & N: A powerful partnership

Potassium and Nitrogen are closely linked. While only 1% of a plant’s K is used for structural growth, 60–70 kg K/ha is needed to achieve yield, and up to 200 kg K/ha may be required to fully support nitrogen uptake. Potassium helps maintain cell turgor – especially important as over 70% of a plant cell’s volume is the vacuole.

Without adequate K, nitrogen uptake and utilisation are significantly reduced. In fact, low potassium levels can limit the effectiveness of applied nitrogen, as demonstrated in trials such as the Hoosfield study at Rothamsted.

Why apply foliar potassium?

Of the potassium applied to soil, crops typically recover only around 40%. In situations where soil K is deficient, or when crops are under transient stress, foliar potassium offers an effective and responsive alternative.

Additionally, low K in leaf tissue can trigger sugar secretion onto the leaf surface, creating ideal conditions for pathogen activity. Maintaining optimal leaf K levels can reduce disease risk.

Low leaf levels of K induce the movement of sugars out onto the leaf surface from interstitial fluid

Introducing Wholly K

Wholly K is a unique, foliar-applied potassium formulation, specifically designed to support crops where soil potassium is insufficient or when transient stress reduces nutrient uptake.

  • Formulation: 0:0:20 clear liquid
  • No antagonistic anions – free from chlorides, nitrates, or sulphates
  • Low salt index – reduces the risk of crop scorch
  • Enhanced with PGA (Pyroglutamic Acid) – to maximise NUE and crop performance
Response of spring barley to N fertiliser on soils with different levels of exchangeable soil K (KEX) Hoosfield, Rothamsted

What is PGA and why does it matter?

PGA (also known as pidolic acid) is a natural plant metabolite that supports two key processes:

  1. Enhancing carbon fixation by boosting photosynthesis
  2. Improving nitrogen assimilation, increasing uptake and internal conversion to amino acids, supporting overall crop growth and productivity

This makes Wholly K more than just a potassium source—it’s a precision tool for boosting nutrient efficiency across the board.

Trial performance & application

In winter wheat trials (2018–2019), Wholly K demonstrated clear yield benefits over untreated plots. And in spring barley, trials showed that applying nitrogen without correcting potassium deficiency delivered diminished returns—underlining the need to balance both nutrients.

Using Wholly K in your programme

Ask yourself:

  • Are your soils K deficient?
  • Is potassium availability inconsistent?
  • Are your crops under transient stress?

If yes to any of the above, consider a targeted foliar approach.

 Recommended application rate:
1.0 L/ha Wholly K

Wholly K is particularly valuable in broadacre crops, where potassium costs are high and even high-K soils can experience uptake issues due to stress. Its low salt index means lower risk of crop damage—even in sensitive conditions.

The bottom line

Wholly K connects the dots between potassium delivery and nitrogen efficiency—giving you a smarter, more responsive way to support crop health and performance.

Ready to take control of potassium management?
Wholly K is your foliar insurance policy – cost-effective, crop-safe, and proven in the field.