Reaktion des boden-c- und n-gehaltes auf düngung – ergebnisse von dauerversuchen in Halle/S., Deutschland: Response of soil c and n content to fertilization – results of long-term trials at Halle/S., Germany

Results about the influence of different fertilization on the dynamic of C and N content in soil are presented from the Eternal Rye trial and from the long-term fertilization trial Field F founded by Julius Kühn in 1878 and by Karl Schmalfuß in 1949, respectively. Mainly the organic (i.e. farmyard manuring and straw fertilization) but also the mineral N fertilization had a significant effect on both parameters. New steady states typical for applied fertilization treatments have been reached after decades of trial, e.g. the residual effect of 60 years of farmyard manuring on soil and plant is significant even 50 years after cessation of fertilization. Furthermore, rotation, soil, ploughing depth and atmosphere emmision influenced soil C and N turnover. The effect of fertilization was modified by even slight differences in soil characteristics. The results confirm the importance of long-term trials for management strategies in sustainable agriculture.