The impact of livestock farming activity on the quality of surface water.

The most dangerous pollution sources are intensive agricultural activity and livestock farming, whose production waste has a negative impact on soil and water quality. Livestock farming is separated into two systems: indoor (pigs and poultry) and pasture-based (livestock and sheep). Numerous studies aimed at elucidating how different systems affect the environment have been performed. In Lithuania, the biggest environmental problems are caused by 24 farms with more than 5000 pigs, 21 poultry farm with more than 1000 chickens, 2179 cow-cattle farms larger than 50 places, and about 200,000 sheep. We aimed to assess the quality of surface water in the Kaunas region next to the pig and livestock farms. In 2008-2017, seven livestock agricultural companies and seven larger farmers were regarded as potential sources of pollution in the Kaunas region. Half of these sources were pig farms, and the rest were livestock farms. Locations next to potential agricultural pollution sources were chosen to monitor the surface water. The results indicated that although the agricultural areas, number of livestock units, and nitrogen rate per 1 ha were similar between the pig and livestock farms, the activity on the pig farms affected the surface water quality more than that on livestock farms. As the number of livestock units (LU) increased on the farms, the pH decreased and the suspended materials, nitrates, and phosphates increased in the surface water. With increasing nitrogen kg/ha, the pH values decreased, thereby yielding more acidic water. The intensity of agricultural activity did not affect the water quality near the livestock farms, except for livestock units (LU), which affected the pH.