Case study: Economics of spring feeding in grassland

Abstract

Change in world energy prices influences the price of mineral fertilisers. To meet the globally growing need for food farmers are extending the production of milk and meat, facilitating thereby an increase in manure production. The distance of the grassland from the farm centre and fertiliser prices influences farmers' choices regarding the art and logistics of fertilising. The aim of this study is to compose a calculation model to compare the economic aspects of different fertilising options considering the grassland distance and the art of fertilising. The model contains components from the method applied to evaluate the rationality of exploitation of a field, considering the costs pertaining to field distance. Spring N feeding of grassland was simulated and five technologies were compared with the model. In calculations it was presumed that manure comes from a farm's own production and the costs arise only from hauling and distribution. In comparison with mineral fertiliser, these costs increase with driving distance; therefore it is economical to use only manure near the farm compound. In average Estonian forage production conditions, the N rate 75 kg ha -1 minimum value using cattle slurry distribution with a shallow injection system is more economical than using mineral fertiliser. It can be also concluded that compared to a distributor, using a tank truck for hauling slurry is beneficial on farther parcels (under the conditions in the simulation, farther than 4.2 5 km), as in those cases the hourly operation cost of the slurry distributor is very high.