Impact of agriculture and land use on nitrate contamination in groundwater and running waters in central-west Poland.

Agnieszka Ewa Lawniczak,Janina Zbierska,Bogumił Nowak,Krzysztof Kanas,Artur Grześkowiak,Krzysztof Achtenberg

doi:10.1007/s10661-016-5167-9

Abstract

Protected areas due to their long-term protection are expected to be characterized by good water quality. However, in catchments where arable fields dominate, the impact of agriculture on water pollution is still problematic. In Poland, recently, the fertilization level has decreased, mostly for economic reasons. However, this applies primarily to phosphorus and potassium. In order to evaluate the impact of agriculture on water quality in a protected area with a high proportion of arable fields in the aspect of level and type of fertilization, complex monitoring has been applied. The present study was carried out in Wielkopolska National Park and its buffer zone, which are protected under Natura 2000 as Special Areas of Conservation and Special Protection Areas. The aim of the study were (1) to assess the impact of agriculture, with special attention on fertilization, on groundwater, and running water quality and (2) to designate priority areas for implementing nitrogen reduction measures in special attention on protected areas. In our study, high nitrogen concentrations in groundwater and surface waters were detected in the agricultural catchments. The results demonstrate that in the watersheds dominated by arable fields, high nitrogen concentrations in groundwater were measured in comparison to forestry catchments, where high ammonium concentrations were observed. The highest nitrogen concentrations were noted in spring after winter freezing, with a small cover of vegetation, and in the areas with a high level of nitrogen application. In the studied areas, both in the park and its buffer zone, unfavorable N:P and N:K ratios in supplied nutrients were detected. Severe shortage of phosphorus and potassium in applied fertilizers is one of the major factors causing leaching of nitrogen due to limited possibilities of its consumption by plants.

Highlights

Eutrophication is a key factor causing degradation of water quality, which restricts its use
The results demonstrate that in the watersheds dominated by arable fields, high nitrogen concentrations in groundwater were measured in comparison to forestry catchments, where high ammonium concentrations were observed
Our study indicates that measured action combined with long-term monitoring data should be applied for proper protection of Wielkopolski National Park, in the protected area and its buffer zone and in the whole catchment

Summary

Introduction

Eutrophication is a key factor causing degradation of water quality, which restricts its use. One of the most problematic is nitrogen and phosphorus leaching from arable fields to groundwater and surface water as a result of higher amounts of these nutrients applied in natural and mineral fertilizers compared to plant requirements or supplied in adverse conditions (Billen et al 2013; Kyllmar et al 2014b). Nutrient leaching depends on several factors, primarily fertilization level, type, and timing of fertilizer application; the method of their application to the soil; properties of soils (i.e., pH, structure and organic matter content), types of crops and their fertilizer requirements; method of cultivation and agronomic practices; and the level of animal production (Bechmann 2014; Kyllmar et al 2014a, 2014b). Weather conditions and catchment land use have a crucial impact on the intensity and quantity of nitrogen leaching (Jiang et al 2014; Yoon 2005; Woli et al 2008)

Objectives

Methods

Results

Discussion

Conclusion