Various types of poultry litter products are being delivered to farmers at the moment, but it is very important to get an analysis done (N, P & K) to check its suitability for winter crops.

For example, one available product is a very dry layer manure (almost 90% dry matter). This is the same layer manure that was trialled by Teagasc in spring barley for the last two years. “Rocket fuel” is a term sometimes used to describe poultry manure, and this high dry matter product is precisely that.

One tonne of this product contains approximately 17.5kg of available nitrogen (see Table 1), along with a nice balance of other key nutrients. At an application rate of 2.5t/ha, this manure supplies 44kg/ha (35 units/ac) of available N. This is an ideal organic manure for spring cereals but its high nitrogen content makes it completely unsuitable for ploughing down for winter cereals.

No farmer would apply 35 units of chemical N to winter barley as it would promote too much autumn growth. Poultry manure should not be treated any differently.

Early October-sown winter barley will have a root system that is adequately developed to tap into this ploughed-down manure within four to five weeks. And if the crop does not take up all of the available N, the majority of the remainder may be leached. Given normal winter rainfall in Ireland, only about 10% of the available N (3.5 units) will still be available in the soil for crop growth in spring.

So, using high dry matter poultry manure in winter cereals is a very inefficient use of nitrogen from this valuable resource.

Think wisely where you use it. Winter oilseed rape is a more suitable crop to make more efficient use of this product. If you have missed that window of application, consider storing it for spring crop use.