RESUMO
Favourable economics of handling and application of manure are of fundamental importance to encourage the implementation of emission-reducing application techniques. The economics of manure application depend on the costs of the equipment and the time to carry out the field operation. In this study the costs of application techniques designed to reduce ammonia losses were assessed and compared with the costs of conventional broadcast spreading across a range of farm characteristics. A model was developed to calculate the costs and time requirements of manure application. Data on factors affecting the costs were used from different countries in Europe. The calculations showed that for a range of farm characteristics with a manure production of 1000-3000 m(3)y(-1), the costs of manure application by trailing hose, trailing foot, shallow injector and arable land injector were approximately 2 m(-3) higher than for broadcast spreading. The cost difference between broadcast spreading and the other application techniques decreased with farm size. The average additional costs of manure application by a trailing foot or a shallow injector decreased by 15% on small extensive farms to more than 50% on intensive farms, when the fertiliser value of the nitrogen was taken into account. The field application itself took less than 50% of the operating time in the process of the manure handling and application. With an increasing application rate, the relative contribution of the time for field application decreased.