Mineral and organic fertilization efficiency in long-term stationary experiments

In long-term stationary experiments under different soil-climatic conditions, an influence of mineral and organic fertilization on yield of winter wheat, spring barley and potato tubers was evaluated. Statistically significantly lowest grain yields of winter wheat (4.00 t/ha) and spring barley (2.81 t/ha) were obtained in non-fertilized plots at all experimental sites. In the case of potatoes, the lowest yield of dry matter (5.71 t/ha) was recorded in the control plot, but the result was not statistically significant. The manure-fertilized plot gave the average yield of wheat higher by 30%, of barley by 22%. Application of sewage sludge resulted in wheat yield higher by 41% and barley yield higher by 26% over control. On average, application of sewage sludge and manure increased the yield of potatoes by 30% over control. The highest yield was obtained after application of mineral fertilizers; average yield increased by 59, 50 and 36% in winter wheat, spring barley and potatoes, respectively. No statistically significant differences among the plots with mineral fertilizers were observed. At different sites, the yield of studied crops varied; however, the effect of fertilization on yield increments was similar at all experimental sites except for Lukavec. It is the site with the lowest natural soil fertility, and it showed the highest effect of the applied fertilizers.