Dried Poultry Manure

Abstract

THE possibility of making better use of poultry manure is receiving considerable attention at the present time and in the Journal of the Ministry of Agriculture (vol. 39, p. 656) R. Sayce and F. Hanley give an interesting account of the production of kilndried poultry manure. The kiln, which is very similar to that used in maltings, is a ventilated brick building with a corrugated asbestos roof which is lined with asbestos sheeting. It is heated with an ordinary coke furnace and a system of flues. After a preliminary drying in the air for about two days, the manure is spread on the kiln floor to a depth of 7–8 in., being turned occasionally during treatment. The time required for the drying process depends on the state of the material, its depth on the floor, weather and other conditions, but 48 hours should be sufficient for average material 6–7 in. deep, the maximum temperature during the process usually approaching 300°F. Four tons of manure may conveniently be treated at a time and will yield approximately two tons of dried material, which should not contain more than 7–10 per cent moisture if it is to store satisfactorily. Some loss of nitrogen during the drying is unavoidable, but analyses show that the final composition of the poultry manure closely resembles that of other organic fertilisers, which sell at £3 10s.–£5 a ton, at present in considerable demand in market gardening districts. In addition, the constituents are present in a readily available form.