How to manage and prevent pasture damage
Your pasture serves as both the home and the nutrition source of your livestock. The health of the pasture is therefore inextricably linked to the health of your herd, whether cows, sheep, or something more exotic.
To some degree pasture damage is inevitable. Your herd is constantly clearing your ground cover, leaving little for the soil to hold onto. Livestock, particularly cows, are heavy beasts, and when rain further softens the soil, hooves are likely to puncture the surface.
The consequence? A waterlogged, churned, compacted and muddy pasture that can affect the productivity of the field well into the future. This is ‘pugging’.
What is pugging?
Pugging sees waterlogged ground being continually churned up and compacted by heavy livestock. It generally occurs in areas of high rainfall and dense soils, with herds of cows the most common culprit.
Pugging is incredibly damaging to soil. It compacts the earth, denying grasses and other ground covers the aerated ‘crumb’ type soil structure that they need to grow. The flow-on consequences of this compaction can be severe:
- Poor drainage: Pugging is a self-fulfilling cycle – the compacted earth is unable to drain, becoming more waterlogged, and even more prone to further pugging.
- Reduced plant growth: With oxygen unable to reach roots, pugging can reduce pasture growth from 20%-80%.
- Weed infestation: With ground cover struggling to grow, hardy and opportunistic weeds will take over.
- Herd health issues: Pugged pasture can be a breeding ground for microorganisms, making your livestock vulnerable to mastitis, toxaemia, grass tetany, cracked teats and lameness.
- Run-off and unevenness: Poor drainage will result in run-off, leaching valuable nutrients from your soil, and even transforming the topography of your pasture.
- Years of lost productivity: In the worst-case scenarios it can take a pasture years to repair itself.
How to prevent pugging?
Livestock owners in pugging-prone areas have a battle on their hands to entirely prevent it, which can prove impossible. The aim should instead be to reduce the problem as much as possible, which can be done through the following strategies:
- Avoid grazing in paddocks where pugging is likely, particularly after heavy rain.
- Maintain a healthy amount of pasture cover – don’t let your herd strip a paddock bare.
- Utilise a stand-off pad or feed pad when your pasture is vulnerable.
- Use a temporary back fence to ensure your herd doesn’t walk back over old ground (but be careful that the fence doesn’t crowd the herd into a small space, and increase the likelihood of pugging.)
- Use an ATV or motorbike to check stock, rather than a tractor or other heavy piece of farm machinery.
- When moving your herd, direct it over thick and healthy pasture.
How can pastures be repaired?
While prevention is always better than cure, even the best laid anti-pugging plans can be torpedoed by a surprise storm or particularly susceptible soil. Pugging is simply a reality of life for many farmers, so let’s take a look at how to fix an already damaged field.
Assess the damage
Once you’ve identified areas of concern on your farm, rate the pasture damage:
- Category 1: Mud with little to no pasture.
- Category 2: Pasture exists but is severely damaged.
- Category 3: Pasture and soil has light to moderate damage.
It may help to dig holes in the most seriously affected areas to get a sense of the damage. The deeper the soil is compacted, the more work will be required to fix it.
2. Prepare the soil
The strategies you’ll use to fix and prepare the soil will be guided by your assessment of the damage. Referring back to the categories mentioned above:
- Category 1: Serious damage demands serious action. Subsoil aeration will be necessary, and deep enough that it reaches to the bottom of the compacted soil. This should be followed by cultivation. You’ll need to give the soil the opportunity to dry out in between times if this effort is to be successful.
- Category 2: While subsoil aeration is unlikely to be necessary, the ground may need to be rolled to ensure seed depth accuracy. Choose a large roller and use minimal water.
- Category 3: A light roll and a dose of fertiliser might be all that you need!
Once the soil is prepared, it’s time to encourage regrowth.
3. Sow seed
For category 1 soils, drilling seed into the earth is likely to be more effective than simply broadcasting it, even when properly prepared. Category 2 soils may need a light reseed, and broadcasting is generally more viable in these cases. Category 3 soils, meanwhile, should regrow of their own accord.
4. Manage pasture regrowth
Your job doesn’t end when the seed hits the earth. You should keep your herd off the resown areas where possible. Grass should pass the ‘pull test’ before grazing recommences. Nitrogen fertiliser is a must and should be applied at regular intervals over the coming years.
Finally, it’s important to note that pugged soils are always more prone to re-pugging than unpugged soils. You should take the utmost care with seriously affected areas in the years that follow.
The cost of not maintaining the health of pastures
When faced with pugging, there is another option: do nothing. This might sound tempting, but the cost of inaction can be great. According to Dairy NZ pugged soils:
- Reduced pasture growth by 20% – 80% (depending on pugging severity.)
- Reduced ryegrass tiller density by 39% – 54%.
- Reduced pasture utilisation by up to 40%.
- Can last for up to two years if left untreated.
Let’s say that each hectare of damaged pasture previously boasted production of 14,000kg. A drop of 40% is equivalent to a loss of 5600kg of pasture, which at 20c/kg equates to a loss of over $1000/ha. Keeping in mind that yield reductions of double that figure have been recorded, and that the ill effects of pugging can last for multiple years, it’s clear that pugging is something that a farmer cannot afford to ignore, or even take lightly.
If your land is affected by pugging, the expert team at SmartShelters are ready to help. Boasting a century of experience in Kiwi conditions, our covered feed and stand-off pads have been designed to rehouse your livestock during wet weather, keeping them comfortable while ensuring your pasture stays pristine.
To discuss a truly smart feed pad shelter solution, chat to our friendly team today!