One of the most important problem of the Polish agriculture is soil acidification and the low content of basic nutrients as well as high mobility of heavy metals. The research was conducted on the basis of a long-term (38 years) field experiment, which was located on the area of the UTP Research Station in Wierzchucinek that was found in 1974 on Podzolis (WRB 2014). Natural fertilizing or liming were not applied in the research. The effect of the 38 years' application of high doses of nitrogen (N83, N167, N250) and potassium (K0, K53, K105, K158) as well as the fodder-industrial crop rotation was soil acidification. The fertilization applied in the experiment significantly determined the contents of the assimilable forms of copper and zinc in the examined soil. On average, independent of a dose of potassium applied, the highest values of the parameters observed were found after the highest doses of nitrogen (N250) were applied. Essential correlations between the contents of the examined microelements in soil samples and their basic chemical parameters were also determined. The contents of the assimilable zinc and copper were significantly lower than the national average, but they all were in the low and average soil ...
We evaluated how organic manures (farmyard manure, dung water and poultry slurry), different doses of mineral fertilizers (three treatments), combinations of manures with mineral fertilizers (three treatments), and potato varieties (four varieties) influenced potato tuber yields in our long-term fertilizer experiment in Prague, established in 1954.According to our crop rotation, potatoes were planted every ninth year, starting in 1962. Four potato varieties were used since then (Krasava, Radka, Korela, Dita), all of them were medium-maturing and consumable.The average potato yield was 19.1 Mg ha-1 at the beginning of our experiment (1962, var. Krasava) and 37.5 Mg ha-1 in 2007 (var. Dita), showing low suitability of the experimental site for potato production. The mean tuber yield of varieties Krasava, Radka, Korela and Dita was 18.5, 17.1, 30.2 and 37.5 Mg ha-1, respectively. The effect of organic manures was principally comparable with mineral fertilizers. Increasing doses of mineral fertilizers were not related to appropriate increase in tuber yield. Therefore, application of N, P and K around 50, 50 and 144 kg ha-1, respectively, gives fair yields in such non-optimal production area, as is our experimental site. In the case of warm and dry seasons, even high doses of the mineral fertilizers can't ...
