Preventing Staggers with Grassland Nutrition

As we move into 2024 thoughts should turn to the nutrient requirements for grassland, both grazing and silage.  One of the main concerns that gets raised most years is grass staggers caused by luxury uptake of Potash.

Staggers can occur when there is rapid uptake of Potash in young fast growing grass with low dry matter, i.e., spring grass.  The increased levels of Potash in grass affect the Potash:Sodium and Potash:Magnesium ratios.  The ideal level for both these ratios is between 10 and 20:1.  With increased levels of Potash in the grass the ratio can rise to >30:1 which is when staggers is a risk.  As Potash levels rise the Sodium and Magnesium mineral content of grass falls.

The main use of sodium in the animal is for production of saliva which is used to help maintain the correct pH in the rumen.  A lack of sodium means the animal will replace it with potassium which leads to an increase in the Potash:Sodium ratio in the rumen which then reduces the level of magnesium absorbed by the animal into the blood, which can lead to staggers.

To ensure that the risk of staggers is reduced, it is important to test soils and herbage with a detailed analysis to see what the ratios are like.  If there is an issue then corrective actions can be taken:

• Applying additional sodium will help to balance the higher Potash.  This can be done using Cheshire rock salt.  There won’t necessarily be a yield response but there should be an increase in dry matter intake.  It can also have a positive effect on forage quality lifting D Value and sugar content.  Aim for 0.5% sodium in the dry matter.
• Applying magnesium, e.g. Kieserite, will help raise levels in the plant and improve grass yields.  The aim is for an index of minimum 2.  If the pH is low and lime is needed, using a product called “Mag Lime” will both reduce acidity and raise magnesium levels.

The important action first is to soil/herbage test.  If you don’t measure you can’t decide on the current course of actions. 

To discuss this further, contact Phil at pcooper@fcgagric.com (FACTS)