Effective muck management methods can help farmers save time and money, giving true meaning to the phrase where there’s muck there’s brass, explains Cheshire based agricultural consultant Robert Brock, distributor for slurry additive firm Epizym.

Rather than being a headache slurry should be viewed as a farm asset. For example, based on recent prices for N, P and K fertilisers, slurry produced by 100 dairy cows over a winter housing period has a potential value of almost £3,800 and a 1000-place finishing pig unit can produce slurry with a value of around £4,358 each year. †

Get the system right
For successful slurry management, make sure your storage system is right for your farm. It should be as simple as possible with minimum potential bottlenecks. There’s advice out there for pig farmers (www.bpex.org.uk; www.environment-agency.co.uk) on constructing pig buildings that reduce ammonia output. Under floor slatted tanks can be problematic due to the poor removal of slurry solids during the emptying process. This gives a build up of solids resulting in reduced storage capacity compounded by added cost to remove the solids. It makes sense to design systems that offer the potential to remedy problems easily, whether in lagoons, slatted tanks and so on.

Prepare properly
Good preparation of slurry is a step that too many farmers miss out. To take the hard work out of slurry it’s worth investing in an additive. Most types of slurry tanks and lagoons are notoriously difficult to properly and economically agitate and empty completely due to the build-up of crusts, solids and sludge in the slurry system. Additives can digest and liquefy slurry, and so significantly reduce the time it takes farmers or contractors to stir and empty tanks and lagoons. An additive also creates a more homogeneously mixed, liquid slurry. This helps ensure when it’s spread on the land, there’s an even spread of fertiliser nutrients to crops.

Dairy farmer John Pidsley, based in Ledsham, South Wirral, has been using Epizym slurry additive for ten years and has saved £4,000 every year. “I’ve found that slurry treated with an additive is far easier to handle. There’s very little crust and it has a more even consistency, even before mixing. It’s greatly reduced the time I spend on stirring the stores before spreading - it only takes me an hour to an hour and a half now. This allows us to take advantage of weather windows for spreading.”

He also appreciates the boost in fertiliser value the additive brings. “When I put the thinner slurry on the land the grass grows noticeably quicker almost straight away. So much so, that by the springtime, I drastically reduce the amount of fertiliser I use, buying only a couple of bags almost as an ‘insurance policy’.”

Analyse your slurry
Slurry analysis enables reliable and cost effective fertiliser planning. It’s best to measure or at least estimate nutrient content rather than rely on guesswork. Make sure the sample taken for analysis is the equivalent of an ‘average’ of what is found in your store. To do this, take several samples from various positions within the store, mix them together and then take a representative sub sample. This can then be analysed in a laboratory or be tested with a slurry N meter or slurry hydrometer on the farm. FACTS registered advisers can then help you to decide your optimum fertiliser usage.

Spread it at the right time
One of the most disheartening sights is slurry being spread at the wrong times of the year. This is like pouring money down the drain. Apply slurry to your land at times of maximum crop uptake – generally during the late winter/spring period – to increase the utilisation of manure N and reduce nitrate pollution. Avoid spreading during the autumn-early winter period, as winter rainfall washes nitrate out of the soil before crops can use it.

Nutrients losses vary. Losses of phosphate and potash are low but increase if it’s surface spread and then washed off the field through heavy rain. Applying to coarse sands or gravels, or through cracks or subsoil channels direct to field drains could also lead to losses. Nitrogen on the other hand is easily lost through volatilisation of gaseous nitrogen to the atmosphere, and is leached out of the soil and gaseous loss (ammonia) from storage tanks. Application timing, method and amount applied at any one time are essential to try to minimise these losses.

The efficiency of summer applications is likely to be increased due to reduced leaching losses, as the soil will be drier and the crops are already growing. Splash plate spreading in the summer can give an increase in gaseous losses through the action of sun and heat. Nutrient utilisation can be maximised with band spreading, or better still, injection.

Dealing with smell and flies
Smell is a big issue for farmers in or near residential areas. With the IPPC regulations focusing on odour control, this is a key area for pig and poultry farmers. There’s a lot that can be done to minimise smell.

Do obvious courteous things, like checking the wind direction before spreading. Avoid spreading at the weekends or in the evening when people are at home.

Again, using a slurry additive can reduce odour significantly - by up to 55%*. Smell and flies were a problem in the mid 90s for John Gray, who farms 18,000 pigs each year. “I installed slatted accommodation and very soon the neighbours complained about the smell. Not knowing very much about slurry digesters, I saw an advert and called up to get some advice. Within six to eight weeks of using Epizym the smell had cleared up and the complaints had stopped.” John’s wife was also a lot happier, as their conservatory, once thick with flies, became pleasantly clear of them as they had no slurry crust to land on to lay their eggs.

Use slurry correctly for your soil and what you farm
Silage grass needs much more potash than phosphate, making cattle slurry ideally suited. Using manures on grazing land can lead to problems such as rejection or recycling disease. When used properly, slurry adds organic matter to soil and improves the soil structure. It can increase water holding capacity and drought resistance in lighter and sandy soils. Plan applications well in advance to maximise the use of your storage capacity, cropping, slurry nutrient values, soil types and keep within regulations.

Keep an eye on regulation
Finally, rules surrounding the storage and use of slurry are updated regularly, for example NVZ maximum rates of manure nitrogen per hectare per year. Keep abreast of these changes. It makes sense to update storage systems and processes in line with them to avoid cautions or expensive fines later.

Farmers wanting more information on Epizym products should call 0800 083 0614 or visit www.epizym.com

Robert Brock is a FACTS registered adviser and distributor for slurry additive firm Epizym. For further information or advice on slurry management contact him on 0800 083 0614 or visit www.epizym.com

† Source: Calculated using slurry output figures from RB209, DEFRA guidance booklet, 7th edition.

* Source: Increased total-N in pig slurry systems by as much as 33% and ammonia-N by as much as 57% - Silsoe Research Institute, Olfactometer Unit. In cattle slurry systems, the figures are 11% and 51% respectively – UK Dairy Research Farm