As you’re probably aware – your cattle’s manure can be your dairy farm’s best friend.

However, only if you do a good job with it.

Not using your cows’ manure or doing a good job with it – can be a real loss for your farm. Almost anything on a dairy farm can be managed and utilised to gain your farm’s more profit. Many dairy farmers fail because they are not taking advantage, in the best way possible, of every resource that they have.

What does doing a good job with manure mean, though?

Heifers on pasture.

First off – it means making sure you have a good pasture management plan in motion and in action. With a good active pasture management plan, you will be engaging in correct and beneficial rotational grazing on your paddocks. Your cows are natural manure spreaders. If you have a good rotational grazing plan going on – your cows will naturally take care of spreading the manure and fertilising your pasture.

A good pasture management plan with a correct rotational grazing plan will also imply that all your paddocks will get fertilised. You can also plan your rotational grazing based on what paddocks need to be fertilised – knowing your cows will be grazing and shitting (if there is any article to swear in!).

At a dairy farm, you also have the feces that your cows leave behind while getting milked and when getting fed additional feedstuff. If you want to collect it there are several ways in which you can store it and several ways in which it can be spread. Some with more benefits than others.

But, first let’s have a look at why cow manure is good for your soil:

Cow manure – without bedding and water – have nutrients that are valuable for your soil and your grass’ health and growth rates. The three most important nutrients are N (nitrogen), P (phosphorus) and K (potassium) – on top of these three, manure also has a few micronutrients. In manure, we also find calcium, magnesium, sulphur, boron, copper, iron, manganese and zinc.

Fresh manure (27,000 kg/ha) from lactating cattle can provide 180 kg of nitrogen, 27 kg of phosphorus and 83 kg of potassium per ha, according to this Dairy Cattle article. However, is this enough for the nutrient needs of your soil and the needs of your pasture? Well, let’s have a look:

The grass nutrient needs (per 1 tonne of dry matter) for grass maintenance are:

  • 225 kg/ha of nitrogen over the growing season with irrigation
    • 70 kg in early spring
    • 55 kg in mid-December
    • 45 kg in February
  • Between 115 and 225 kg/ha of phosphorus
  • Between 180 and 400 kg/ha of potassium

Depending on the amount of manure you have – it can be insufficient, enough or more than enough to fertilise your soil and pasture.

Only from grazing, cattle manure might not be enough – but it can be a great natural and free occasional supplement when you are grazing your paddocks. However, stored manure – especially if stored appropriately, can be closer and more sufficient to your soil and pasture’s fertilising needs.

Test your soil

Make sure to test your soil before applying a large quantity of manure! In another one of our blog posts, we describe in detail how you can take a soil sample and do a soil test. Once you have information on the nutrients currently present in your soil – you can decide how much manure you need to apply.

So then let’s get crackin’ and look at the best manure storage systems and best manure-handling methods.

Cow Manure or Effluent Storage Systems

  1. Single Storage Ponds
    • The single storage ponds system is – as you might imagine – a single pond used as a storage pond for the wetter months of the year. This is a great system to use for periods when rainfall exceeds evaporation, and runoff is a risk. It’s also a great system to use when applying the manure quickly to the pasture and not risking the nutrients to set out.
    • It’s a very effective and simple system to store your manure. However, you do need to create a pond, to dislodge it every few years and give it regular needed maintenance. It also depends on soil type and water table depth. This system also requires agitation to access the manure’s valuable nutrients, especially since Phosphorus and Nitrogen sometimes settle in the lower layers of the pond.

  2. Multi-Pond
    • The multi-pond system is – as you can imagine again – a manure storage system that involves two ponds. One pond acts as a settling pond, while the other one is the storage pond. There are several factors to consider when designing a multi-pond system, such as anaerobic digestion, pathogenic or odour treatment, solid settling or storage through winter.
    • The great thing about this system is that it allows you to recycle, so you do not need a large volume of water to service floor wash and hydrant systems.
    • However, even though I would like the multi-pond system to be perfect for your dairy farm – it isn’t.
    • It poses its own set of challenges.
    • The first one is that it takes quite a lot of space – so you need the land for it. Secondly, the settling pond requires a bit more management and maintenance than the storage one. Lastly, important nutrients can get trapped in the lower sludge layers and take nutrients away from your fertilisation.
    • Even so, the multi-pond system is a very worthy option and it’s quite eco-friendly

    State of the art multi stage effluent system at the University of Sydney.

Don’t store – apply!

If you do not want a storage system – you have the option to apply the manure directly. How? The most common way is to pump it directly to the pasture through a fixed or movable manure irrigation.

It’s the most affordable way to do it and you need no ponds, no space for ponds of ponds’ maintenance. It also promotes more effective use of nutrients and it’s better for lighter, free-draining soils.

There are challenges to having no storage system but applying your cattle manure directly. You have to find the right effluent equipment to transport it to your paddocks and the right sprinklers. All of this equipment needs maintenance and is quite labour-intensive.

Even so, it’s a much simpler and nutrient-rich method of managing your cattle’s manure.

Manure-handling and dairy effluent plan

Once you choose which manure-handling system is best for you and your dairy farm – at least temporarily – you need to start planning how to apply the manure to your paddocks.

When developing your management plan you need to have in mind your very own farm and characteristics such as distance to waterways, soil type and how the manure-handling management system can be integrated into the infrastructures within and surrounding the farm.

It’s also good to keep in mind all your other dairy farm management strategies such as pasture management, irrigation and fertiliser application management. If you want to find out more about how pasture management can help you increase your dairy farm’s profit – read more about it here.

Once you have everything in mind related to your farm, you can start designing your manure-handling management strategy.

There are a few key components or stages that can help you with it:

1. Separation of solid and removal of fibre

Removing manure solids and fibre, debris, gravel, stones, sand, and other coarse materials from the liquid streams help to ensure the prevention of problems related to other components within the manure-handling system.

2. Transportation

How will the manure be transported from the source to the point of delivery? What will be used to transport it? How long is the distance between the source point and point of delivery? By answering these questions, you can determine what method you will use for conveyance.

3. Storage

Always pose the question: How will you properly, practically, and effectively store effluent within your farm, especially over the wet months of the year?

4. Application

There are times when working backward can be helpful especially in designing a manure-handling plan. You can determine the area or location where it will be applied, and that can be your starting point. Just make sure that in choosing the area to apply the manure to, you are choosing one where a significant percentage of the paddocks can be applied with it. Also, consider the strategic location for your soil fertility targets.

5. Management

Sadly, a few manure-handling management plans fail, not due to a failed system design, but due to inadequate management. The overall management and maintenance of an effluent system should be prioritized as well. This includes costs of servicing, maintenance ease and frequency, and staff roles and responsibilities.

Having these key components in mind, you are ready to choose the most appropriate effluent system for your dairy farm. Some dairy farmers will benefit more from a single pond system, while others from a multi-pond system while some will be great with direct application. It depends on the size of your farm, resources, and needs for fertilisation.

In the end, make your cow manure management and dairy effluent plans and strategies fit your unique dairy farm and dairy farm requirements.

If you have any questions, write them down in the comment box below! And give this article a share to make sure fellow dairy farmers are managing their cow manure the best they can!

Happy farming!

- Ollie Roberts, 30 October 2019