Study of the effect of fertilizer containing wheat bran on lettuce growth

The aim of the work was to perform growth experiments on a laboratory scale with soil, which was enriched with 2,5 vol. % of wheat bran/coffee grounds/biochar and to study soil and growth characteristics on Lactuca sativa L. The coffee grounds were added raw or modified by oxidation/extraction. Phytotoxic properties of coffee grounds were confirmed by germination tests, although there was an effort to reduce the content of phenolic substances by oxidation /extraction. Soil additives caused an increase in content of organic matter, water capacity, pH and conductivity of all mixtures compared to the control soil. Elemental analysis of soils before cultivation did not show any positive effect on the content of mineral elements compared to the control soil. On the other hand, higher mineral (P, Mg, Ca, K, Mn, Fe, Cu and Al) content compared to soil was recorded cultivation experiments. Chlorophyll a was the most abundant in cultivated plants and reached the lowest concentration in plants grown in a mixture with EXKS. Salads differed in mineral content, too. Salads with the highest content of phosphorus were growed on the mixture BU+OT+PŮDA. On the contrary, content of potassium is salads was negatively affected by mixture with EXKS. Microelements (Fe, Zn, Al, Cu, Cr and Mn) were most affected in the salad by the addition of raw coffee grounds and OXKS2