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SUMMARYIn a greenhouse pot experiment with kohlrabi, variety Luna, we explored the joint effect of N (0.6 g N per pot = 6 kg of soil) and S in the soil (25-35-45 mg kg -1 of S) on yields, on N, S and NO 3 -content in tubers and leaves, and on alterations in the amino acids concentration in the tubers. S fertilisation had no effect on tuber yields. The ranges of N content in tubers and leaves were narrow (between 1.42-1.48 % N and 1.21-1.35 % N, respectively) and the effect of S fertilisation was insignificant. S concentration in the tubers ranged between 0.59 and 0.64 % S. S fertilisation had a more pronounced effect on the S concentration in leaf tissues where it increased from 0.50 to 0.58 or to 0.76 % S under the applied dose. The NO 3 -content was higher in tubers than in leaves. Increasing the S level in the soil significantly reduced NO 3 -concentrations in the tubers by 42.2-53.6 % and in the leaves by 8.8-21.7 %. Increasing the S content in the soil reduced the concentration of cysteine + methionine by 16-28 %. The values of valine, tyrosine, aspartic acid and serine were constant. In the S 0 , S 1 , and S 2 treatments the levels of threonine, isoleucine, leucine, arginine, the sum of essential amino acids and alanine decreased from 37 to 9 %. The histidine concentration increased with increasing S fertilisation. S fertilisation of kohlrabi can be recommended to stabilize the yield and reduce the undesirable NO 3 -contained in the parts used for consumption.

Due to continuous single nitrogen fertilization, we hypothesized a built-up deficiency of micronutrients in crops that would limit plant growth and crop quality. In 2-year field experiments using urea-N fertilized grain maize (Zea mays L.), hybrid KWS 2376 at 0, 120 and 240 kg N ha (1 crop uptake of Zn, Mn, Cu and Fe was studied at DC 32, DC 61 and in the grain harvested. Micronutrient contents at DC 32 stage Á 1st node (aboveground phytomass) and DC 61 Á flowering (ear leaf) were all at levels indicative of adequate micronutrient supply to the crop. At both sampling occasions the Fe:Zn and Fe:Mn ratios were adequate implying that Fe did not inhibit the uptake of Zn and Mn. The application of nitrogen increased the Fe content at the 1st sampling in both years; in the second year the same was also the case for the Zn content. Nitrogen nutrition increased the contents of Mn and Fe at the 2nd sampling only in year 2; in the other treatments no changes were observed in the micronutrient contents. Micronutrient correlations in the grain were discovered between Zn and Mn contents and between Fe and Mn contents. In the second year the highest N-rate significantly increased the Fe and Zn content of the grain compared with the lower rates of nitrogen fertilization. Grain yields were not affected by the rate of nitrogen and ranged between 13.65 and 14.34 t ha (1 (1st year) and between 13.68 and 14.18 t ha (1 (2nd year). Nitrogen fertilization did not reduce the content of micronutrients in the plant or grain of maize. It is evident that the continuous single use of N fertilization so far has not resulted in a micronutrient deficiency of the plants limiting the nutrient density of the grain or reducing its quality.

The influence of application of increasing doses of selenium (0.05 mg, 0.10 mg and 0.20 mg/kg) into soil in pot experiments, with NPK fertilization of spring wheat (Triticum aestivum L., variety Banti), on the biomass yield (grain, straw, roots) and on selenium accumulation was observed. Selenium in the form of sodium selenite (Na 2 SeO 3 ·5H 2 O) and the NPK nutrients in the form of LAD-27, Ca(H 2 PO 4 ) 2 and KCl were applied. The average two-year results showed the expected indifferent effect of increasing doses of selenium on the yield of wheat grain, straw and roots. The differentiated doses of selenium into soil caused a significant increase of selenium content in dry matter (dm) of grain, straw and roots of wheat. The highest content of selenium (0.732 mg/kg in grain, 0.227 mg/kg in straw and 1.375 mg/kg in roots dm) was determined in the variant where 0.2 mg Se/kg of soil was applied. When applying the lowest dose of selenium (0.05 mg Se/kg of soil) the content of selenium was 0.155 mg Se/kg in grain. The selenium content in individual analysed parts of wheat was increasing in the following order: straw -grain -roots.

The effect of fermented pig manure processed on a bed of wooden shavings and fermented for seven days by larvae of house flies on the yield parameters of sunflowers have been investigated on Haplic Luvisol in the pot trial realized in vegetative cage placed on the territory of SAU in Nitra. The experiment consisted of six treatments (0, NPK, Manure1, Manure2, Manure3, Veget). Treatments 0, NPK, and Veget were compared with the treatments Manure1, Manure2, and Manure3, i.e. with fermented manure applied at doses of 4, 6, and 8 t . ha−1.The results showed that application of fermented manure resulted in statistically significant greater stem thickness, higher leaf chlorophyll content, composites and harvest yield of seeds. The plants appeared healthy. Increasing the doses of fermented manure resulted in greater harvest yield of achenes and fat content in them. The dose of 4 t . ha−1 of fermented manure has proven to be insufficient.Out of the tested doses of 4, 6 and 8 t . ha−1 of fermented manure the highest achene yield has been achieved at the dose of 8 t . ha−1 but it was lower than the yield of the treatments fertilized by NPK fertilizers or Veget. From the viewpoint of achene yield quality (fat content) out of six variants the best parameters were achieved with the treatment where fermented manure at the dose of 8 t . ha−1 was applied.The gathered data point towards the applicability and usefulness of manure processed by larvae of flies in agronomy. It is of note, that the manure fermentation period can be significantly shortened, whereby reducing the storage difficulties.