Not long ago, many arable farmers regarded poultry manure as something that would be worth using so long as no money changed hands. Times have changed. Because of the crippling rise in the costs of artificial fertilisers, manure from free range hens is now regarded by many as a good source of nutrients for the crops, at a lower total cost than using compound artificial fertilisers. Therefore, although there are costs in loading, storing and spreading the manure from hens, it is still reasonable for the poultry farmer to expect to receive some money for it, if a contractor is doing the work. If it is used on your own farm, there is a worthwhile saving in the reduction in the purchase of artificial fertilisers. So at last, – muck is money!
There are snags with using poultry manure. It is essential that poultry farmers bring themselves up to date on the legislation about the use of organic manures. You should note the following:
s Have a written agreement with any contractors, so that it is clear who is responsible for the tasks. If an agreement is not made and there is a problem or a pollution incident, both you and the contractor could be held responsible. For example if the manure was spread within 10 metres of a watercourse or 50 metres of a bore hole or spring, a pollution problem could be caused. Where the manure can not be stored undercover, you will also have to agree on the positioning of storage heaps. The heap should be narrow and A shaped so as to reduce odour and ammonia emissions as much as possible. Where there is a risk of fly infestations, due to the manure containing fly larvae, the heap should be closely covered in polythene.
s Nitrate Vulnerable Zones exist and where the manure is being spread makes a difference to the amount of manure that can be used. Farm Limits and Field Limits are mandatory. Is the manure going to be spread where total nitrogen of only 170 kg / hectare / annum is allowed or is it in an area where 250 kg / hectare is permissible?
s As one would expect, it is now essential that records be kept of the amount of manure that has been spread and when this was done. Nitrogen must not be applied to grass between 15 September & 15 January. For other crops, in most circumstances, spreading would not be allowed between 1 September and 15 January. You would need to check whether this applies to the particular crop that is to receive the manure. The snag with nitrogen is that the crop can immediately take up not more than 30% of the nitrogen. Hence the worries about pollution, run off etc. Poultry manure has a high nitrogen content, so there are real risks of pollution if the manure is spread at the wrong time, on a sloping site or at too high a rate/hectare.
s There has to be a manure management plan and manure that has been spread should be incorporated into the land within 24 hours so as to reduce the risks of ammonia loss, fly infestations, odours and run off of nutrients. Ploughing is the best option for this. Try looking on the Environment Agency’s web site and download PLANET (Planning Land Applications of Nutrients for Efficiency and the environmenT). You can download this helpful program from www.planet4farmers.co.uk.
CODES OF PRACTICE
DEFRA have just revised the Codes on Water, Soil and Air and incorporated them into one booklet, instead of the three that have guided farmers until now. It is viewable online on the DEFRA site but has not yet been issued as a hardback. However, you can enter your email address onto the The Stationery Office link (TSO) and you will then be notified when you can get the hardback version sent to you, free of charge. This new hardback version will soon be available from The Stationery Office, P O Box 29, Norwich NR3 1GN. You really do need to be aware of this publication and get a copy for yourselves. The relevant parts of the code are too long to include here, so do your homework and apply the code and regulations to your own particular circumstances.
The section on "Outdoor Poultry" in the new DEFRA code" is brief. For example:
s Sites for outdoor poultry should be chosen with due regard to possible environmental and nuisance problems.
s You should maintain grass cover in poultry runs by using mobile houses or rotating the paddocks so that they have time to recover. In addition, hard standing is necessary around static poultry houses to reduce the risks of puddles.
s You should take occasional cuts of grass from the range areas to reduce nitrate leaching and limit the build up of nutrients.
The Environment Agency is also able to be a source of advice on the use of manures. For example, large poultry units must comply with the stipulations of the Environment Agency. They base their requirements on the Best Available Techniques (BAT) for minimising all types of emissions.
QUALITY OF THE MANURE
So there are a lot of "do’s & don’ts" and I suspect that you are asking yourself, why bother with all of the hassle? The answer is that really you have no choice and if you go about it logically, the manure can be perceived as an asset rather than an unavoidable "curse". So the good news is:
a) The manure is not only good as a fertiliser but it also can help to reduce the costs of having to spread lime on acidic soils. Calcium in the form of limestone is included in your hens’ feed at about 9 – 10%. The hens need it not only to maintain bone strength but most importantly, for forming the egg shells. However, they are not very clever in digesting all of that limestone so about half is left undigested and goes out in the faeces. It used to be said that the area around your free range house became "sour" (acid?) and the lack of vegetation there was partially due to that. I suspect that that is a bit of an ’Old Wives Tale’ because the evidence suggests that the pH of hens’ manure may be about 8.0.
b) The manure is actually a valuable fertiliser. What is more, the first crop uses only a proportion of the nutrients from it. The phosphorus and potash are normally beneficial to the next two or three crops as well.
c) The recognised manurial value of layers manure is:
Dry Matter (%) - 30
Total Nitrogen (N) (kg/tonne) - 16
Phosphorus (P2O5) (kg/tonne) - 13
Potash (K2O) (kg/tonne) - 9
However don’t use these figures because the above values are not applicable to free range production. They refer to the manurial value of the manure from caged layers. You would be worried if the moisture content of the manure in your house really was 70%! If one assumes that the average moisture content of manure (i.e. from the pit and the litter area) from free range houses is actually in the 40 -50% area, the Nitrogen (N) may be about 22 kg/tonne; the phosphorus (P2O5) 18 kg/tonne and the potash (K2O) 13 kg/tonne. However, there are wide variations in the manurial value and it would be very wise to have the manure analysed from your free range houses. It can be affected by the hen’s nutrition; their ventilation; the time of year; amount of litter used etc. etc. Therefore the analyses that you should request are :
Dry Matter (%) and Total N, P & K. Also you should find out what proportion of the nitrogen is readily available to the crop, so requesting ammonium N and uric acid N will do that.
d) Layers manure has a high manurial value. The analyses will safeguard you in the event of a pollution problem, so make sure that you contractor knows just what a potent (and therefore valuable) load he has got.
e) Organic manure is a valuable asset in improving the structure of the soil. Crops grow better where the tilth is good.
.PLANNING ISSUES
The change from 1,000 hens / hectare to 2,000 hens seems to have raised a query about whether there is an overloading of faeces by hens and therefore of N, P & K on the range area. For flocks where say about 20% of the hens go o
