INFLUENCE OF PRIMARY TILLAGE ON PH-VALUE, CALCIUM-CONTENT, POTASSIUM-CONTENT AND PHOSPHATE-CONTENT OF FARMING SOIL IN THE CENTER OF UPPER AUSTRIA .2.

In a long term experiment with various long-tillage methods, the avail ability of selected macronutrients and the pH-value of the topsoil wer e investigated. Experiments were carried out from 1980 to 1990 to chec k the influence of primary tillage in combination with the application of fertilizer and calcium, customary in this region. An increase in t he calcium concentration in the topsoil was observed in all tillage tr eatments except the rotary tiller variants. A small, but not significa nt rise of the pH-value was observed during the experiment. This tende ncy was larger under the ploughing treatment as compared with the grub bing one. In plots which were cultivated with the rotary tiller, a mea surable decrease of the pH by 0.05 units was detected. The mean P2O5-c oncentration ascended from 16 to 22 mg/100 g fine soil because of high er yearly application than the absorption by the crop could remove. No significant differences in phosphate concentration between cultivatio n variants and cultivation depths were detected. Beside the general in crease of the K2O-concentration in the topsoil, significant difference s between the different cultivation methods were observed. The highest value of 44 mg was measured in rotary tillered plots. In the grubbed plot this concentration varied from 37.5 to 41 mg, the lowest values r anging from 27 to 29 mg were found after continuous ploughing.