Application of compost to agricultural soils may be beneficial for crop pro
duction by increasing soil fertility and supplying plant nutrients, however
, any raise of the soil organic matter content may increase the potential f
or unintended groundwater contamination by nitrate leaching. In this paper,
the effect of long-term compost applications on nitrate leaching, soil org
anic matter content, and crop production is analyzed using results of simul
ation scenarios for agricultural sites with loamy and sandy soils. Simulati
ons were carried out using the Danish Nitrogen Simulation System (DAISY) wh
ich describes the nitrogen balance in a one-dimensional soil-plant-atmosphe
re system and considers compost type and application rate as well as manage
ment and cropping practice. Estimations of hydraulic and solute transport p
arameters are based on pedotransfer functions. Data from a 4.5-year period
of field experiments with compost applications in northern Germany as well
as from laboratory experiments with compost amended soil are used for model
calibration. Simulation results suggest that: (i) with respect to nitrogen
turnover the differences between compost types (i.e., non-matured and matu
red) are small compared to site-specific properties (i.e., soil temperature
and water balance) and management practices (i.e., crop rotation) when con
sidering a compost application period of 50 years; (ii) with respect to nit
rate leaching the effect of different compost application scenarios is high
ly sensitive at the sand and relatively small at the loam site; and (iii) r
elatively high crop yields and acceptably low nitrate concentrations in the
drainage water are obtained at the sand site when applying a combination o
f 10 t compost/ha/yr and soil- N-min adjusted mineral nitrogen additions of
about 20 kg/ha/yr to a winter-grain dominated crop rotation. Further optim
ization may be possible by applying reduced rates of the (economically inte
resting) non-matured compost.