Agri-environmental aspects of the activity of farms with different production profiles

The results of own research and literature data indi-cate that the specialization (different production profiles) offarms may contribute to specific threats to the natural environ-ment. Each type of farm exerts pressure on the environment toa greater or lesser extent, which was confirmed by agri-envi-ronmental indicators. Accordingly to literature data the greatestthreat to the environment (water pollution) pose pig farms due tothe high stocking density that contributes to unfavorable (exces-sive) balances of minerals and soil organic matter. Large posi-tive balances indicate the potential losses of these components,mainly due to their leaching to groundwater and surface waters,and consequently to their pollution (eutrophication). On the otherhand, farms with field crops had high risk of decrease in soil fer-tility due to negative balances of nutrients. The smallest threat tothe natural environment and soil fertility were observed for farmswith a mixed plant-animal production as well as cattle farmsspecializing in milk production (with optimal livestock densityof about 1 DJP ha-1). Under certain conditions, cattle farms mayhave too high balances of soil organic matter, and at the sametime negative balances of NPK minerals.