The influence of drained peat soils on diffuse nitrogen pollution of surface water

Abstract

Eutrophication caijsed by excess nutrient loads is the main problem for Estonian surface waters.Even after the (jrastic (decrease in the application of mineral fertilizers at the beginning of the 1990s, the concentrations of nitrogen and phosphorus in many rivers remained at undesirable and unexpectedly high levels. The investigation showed that (drained peat soils are an important source of nitrogen export to the surface waters. Runoff of nitrogen from (drained peat soils is, on average, 1.5-fold higher than from agriculturai lands in Estonia.

Drained coastal peatlands: A potential nitrogen source to marine ecosystems under prolonged drought and heavy storm events—A microcosm experiment

“…Such potentially high available nitrogen in soil is the main reason why large portions of peatlands were drained and reclaimed as farmlands for the past two hundred years (Richardson, 1983(Richardson, , 2008Soper and Osbon, 1922). In Estonia, export of nitrogen from drained peatlands was N1.5-fold higher than from that of farmlands and was the major source of nitrogen export to the surface water (Vassiljev and Blinova, 2012).…”

“…Moreover, most peatlands are located around rivers, lakes and coasts, where they may be a potentially significant nitrogen source to the adjacent aquatic ecosystems. To date, the internal cycle of nitrogen, which is sensitive to climate change, is still poorly understood in peatlands although its impact on adjacent downstream ecosystems may be substantial (Vassiljev and Blinova, 2012;Verhoeven et al, 1988;Wray and Bayley, 2008).…”

Modelling of the Effect of Drained Peat Soils to Water Quality Using MACRO and SOILN Models

“…Analysis showed that the concentrations increase with the increase of water flow but the dependence between them is nonlinear. Such behavior is typical for diffuse pollution of nitrogen [2,21]. …”

“…However, recent data analyzes of Estonian rivers show that nitrogen concentrations have increased in some rivers [1] despite the decrease of fertilizer usage [2]. An increase in nitrogen (N) concentrations has even been detected in watersheds with very low human activity [1].…”

“…This can result in high nitrate-nitrogen (NO3_N) concentrations in the pore water of drained peatlands that is caused by the aeration of peat and subsequent mineralization and nitrification of organic N [9]. In [2] an increase of nitrogen concentrations in some Estonian river basins with high percentage of drained peat soils was observed. Mineralization of nitrogen from peat soils is regarded as another possible source of nutrients in Europe [10].…”