Der Zusammenhang von Aminosäurenstoffwechsel im Boden und Humusniveau im Darmstädter Düngungsversuch

Summary

Since 1980 a long-term experiment has been carried out to compare mineral fertilizers (MIN), composted manure (RM) and composted manure with application of biodynamic preparations (RMBD) at three different fertilizer application rates. The total C and N contents in the topsoil were significantly different between all three fertilizer types. 42.9 to 53.7 % of Nt was bound in 18 total hydrolysable protein amino acids (THAA) including asparagine and glutamine. Amino acid contents in the hydrolysates of the topsoil were significantly different according to fertilizer type: MIN < RM < RMBD. The higher contents in manure fertilized plots were observed even at the lowest rate of fertilizer application. This indicates that differences between the treatments do not depend only on the amino acid supply from manure, but are also influenced by an altered amino acid metabolism in the soil.