(Static nutrient depletion experiment Thyrow. Results after 65 experimental years)

The Long-term Nutrient Deficiency Experiment Thyrow-Results after 65 years of experimentation. The Static Nutrient Deficiency Experiment Thyrow is a long-term fertilization field trial on a poor silty sand soil. Since its establishment by K. Opitz in 1937, it has been carried out unmodified. Eight treatments (without fertilization, farm-yard manure, FYM + NPK + lime, NPK + lime, NPK, NP + lime, NK + lime, PK + lime) caused major differences on the soil fertility status of these low buffered soils. Presently, soil organic carbon content ranges between 390 and 590 mg 100 − 1. During the last 35 years the Corg contents decreased by one sixth independently of fertilization, as a result of longer time of mineralization. The pH value currently varies actually between 4,4 and 6,4, the PDL content between 4,6 and 12, 8 mg 100 g − 1, the KDL content between 2,5 bis 16,3 mg 100 g − 1 and the Mg content between 0,9 and 4,5 mg 100 g − 1. Soil fertility defects caused by acidification and nutrient depletion show greater influence on yields of spring barley than of potatoes or maize. In order of their impact, the minimum effects resulting from a lack of nutrients decrease as following: N > K > lime > P. Applications of 15 t ha − 1 FYM lead a balanced nutrient fluxes for P and K.