Management measures to reduce nitrate pollution in the Schleinitz drainage basin

摘要

In the Schleinitz drainage basin, grassland conversion of a former agricultural field over a period of approximately 6 years led to a 90% decrease in autumn N-min-levels, and humus contents increased from very low to low. At the sampled leachate measuring locations, similar to the two groundwater observation wells, a decrease in the nitrate concentration is evident. Since November 2018, the Schleinitz spring, which previously had a nitrate concentration in raw water of 54mg/l, has fallen below the limit of 50mg/l set by the German drinking water regulations. Indeed, a trend reversal has been achieved throughout the extensive grassland. The REPRO environmental and management system was used for analysis and simulations of different management options. The evaluation showed that the N(min)and humus contents of the arable land are higher and lower, respectively, than those of the grassland. The humus and N(min)values measured in soil samples of the local fields show no noticeable problems, but the groundwater nitrate concentrations have been above the limit for several years. Simulations of various management measures led to higher humus contents and lower N contents.