Land management practice is a decisive factor for the quantities of seepage flow and solute leaching, which constitute two fundamental aspects of land use characterised by potentially conflictive ecologic implications. Efficient water use and intelligent water management are essential for Northeast Germany as a sub-humid region marked by an annual water balance deficit between 80 and 250 mm. Throughout that region, measures are in demand to support groundwater recharge. To meet this claim, knowledge is required about suitable land management systems providing drainage flow sustainable in quantity and quality. Long-term soil hydrological measurements were used to quantify deep drainage and nitrate leaching insitu under undisturbed soil conditions. Deep drainage rates and nitrate losses from arable land managed under various farming regimes (integrated, integrated with irrigation, ecologic and low input) and tillage systems (plough and no till) were quantified in the Pleistocene region of Northeast Germany from 1994 to 2007. Soil water content and tension measurements down to 3 m depth and soil water sampling were used to determine deep drainage dynamics and loss of nitrogen by leaching. As dependent on the management system, the nitrate concentration varied between 40 and 150 mg l -1. In connection with annual deep drainage rates between 100 mm and 200 mm during the study period, the annual nitrogen loss varied between 14 and 41 kg ha -1. Differences in nitrogen loss observed between the farming systems were low, but yields increased and nitrogen losses decreased as a result of irrigation throughout the variants. No-till treatment resulted in reduced nitrate leaching (18 kg ha -1) as compared with the tillage system with plough and tooth cultivator (27 kg ha -1). The suitability of long-term soil hydrological in-situ measurements for quantifying arable management effects on ecological processes - deep drainage dynamics and solute leaching - was confirmed. The trend of decreasing deep drainage was low and not significant. However, due to no significance and quite short investigation period it is not allowed to suggest on climate change effects.
