Application of measures of good agricultural practice to control diffuse n pollution originated from livestock manure
The polluting effects of organic farm wastes can occur in a number of different ways and therefore require a broad range of approaches to control. For example, all watercourses (notably lakes, ponds, rivers, streams and field ditches) adjacent to the production, storage or application of organic wastes are potentially at risk of point source pollution. This risk is different from the diffuse pollution that occurs when the microbial breakdown of manure applied to the soil occurs out of phase with the N uptake of a growing crop and leads to nitrate leaching. Bosnia and Herzegovina is divided into basic river basins as follows: Una, Vrbas, Bosna and Drina flow to the Sava River, which drains into the Danube, while the Neretva, Trebisnjica and Cetina flow to the Adriatic Sea. The biggest emission of organic pollution, then nitrogen and phosphorous is from the Bosna River basin (around 20%). This is followed by Una (15%), Sava (13%), Drina (12.5%), and Vrbas (around 10%). About 30% of above mentioned pollutants goes to the catchment of Adriatic Sea. The spatial distribution of emission is in accordance with the size of the river basin, and the size of the river basin is in accordance with other parameters (population, agricultural activities, cattle-breeding). Exceptions are the river basins of Sava and Ukrina with a bigger concentration of population and more intensive agricultural activities.