Untitled

Abstract

Background. Leaching of nutrients from agricultural areas is the main cause of water pollution and eutrophication of the Baltic Sea. A variety of remedial actions to reduce nitrogen and phosphorus losses from agricultural holdings and cultivated fields have been taken in the past. However, knowledge about the risk of nutrient leaching has not yet reached many farmers operating in the water catchment area of the Baltic Sea. Methods. The nutrient balance method known as "at the farm gate" involves calculating separate balances for nitrogen (N), phosphorus (P) and potassium (K). After estimating all the components of the nutrient balance, the total balance for NPK is calculated and the data obtained is expressed as the ratio of total change (surplus) to the area of arable land on a farm. In addition, the nutrient usage efficiency on a farm is also calculated. An opinion poll was conducted in 2017 on 31 farms within the commune of Puck which is approximately 3.6 percent of all farms located in this commune. The area of the farms is variable ranging from 5-130 ha with an average of 45.82 ha including areas of arable and grass land. The former are on average 30.79 ha with a range of 4.45 to 130 ha while the latter has an average area of 12.77 ha and ranges from 0 to 53 ha. Results. The average consumption of mineral fertilizer in the sample population of farms was 114.9 kg N, 9.3 kg P, and 22.9 kg K•ha-1 of agricultural land (AL), respectively. N surplus in the sample farms being ranged from-23.3 to 254.5 kg N•ha-1 AL while nutrient use efficiency ranged from 0.40 to 231.3 percent. In comparison, P surplus in the sample farms was 5.0 kg P•ha-1 AL with the P use efficiency of 0.4-266.5 percent. Discussion. Individual N fertilizer consumption in the tested farms was higher than the average usage across Poland and in the Pomeranian Voivodeship, compared to the lower consumption of potassium fertilizers. Phosphorus fertilizer consumption was higher than in the Pomeranian Voivodeship, but lower compared to the entire country. Generally, on the basis of designated research indicators of farm pressures on water quality concentrations of total nitrogen and total phosphorus were obtained. CalcGosPuck (an integrated agriculture calculator) will help to raise farmers' awareness about NPK flow on farm scale and thus to improve nutrient management.