Agrochemical use of waste elemental sulphur in growing white mustard

In a one-year pot experiment the effect of waste elementary sulphur on the following parameters was observed: 1. on the chemical composition of mustard plants during the growing season, 2. on the yield of seeds, straw and oil, 3. on the chemical composition of seeds and 4. on the content of the water-soluble sulphur in the soil after the harvest. Elemental sulphur was obtained as a waste material of petroleum refining and was incorporated into a 15-15-15 NPK fertiliser where it comprised 4%. The experiment had the following variants: 1) control (unfertilised); 2) NPK 1; 3) NPK 2; 4) NPKS 1; 5) NPKS 2. The smaller dose amounted to 3.3 g, the higher one to 6.7 g of the fertiliser per pot (6 kg of soil). Moreover all variants were performed in 2 different soils - a medium soil with neutral pH value and a heavy one with alkali pH value. At the stage of 6 true leaves, the content of nitrogen in plants increased in accordance with its dose. Simultaneously, sulphur applied in the NPKS fertiliser improved nitrogen utilization. The difference between the variants fertilised with NPK and the variants with NPKS amounted to 38.9% in the neutral medium soil, whereas in the alkali heavy soil it was as low as 1.4%. The yield of both seed and straw in the fertilised variants was statistically significantly higher than in the unfertilised control variant. However, there were observed no statistically significant differences between the variants with sulphur and the variants without sulphur although both the yield of the seed and straw in the variants with NPKS was higher than in the variants with NPK. The application of elemental sulphur into the neutral medium soil increased the concentration of both nitrogen and sulphur in the mustard seed in comparison with the variants fertilised with NPK only. The difference between them comprises 1.8% and 9.0% in variants with the small and high dose, respectively. In the heavy soil, the trend was opposite. The application of sulphur into both soils resulted in the increase of the oil content in comparison with the NPK variants. Sulphur addition to NPK had a positive impact on the augmentation of the available sulphur content in the soil which can positively affect, particularly the following crops. Still, a drop in the pH value was not confirmed

Agrochemical use of waste elemental sulphur in growing white mustard

In a one-year pot experiment the effect of waste elementary sulphur on the following parameters was observed: 1. on the chemical composition of mustard plants during the growing season, 2. on the yield of seeds, straw and oil, 3. on the chemical composition of seeds and 4. on the content of the water-soluble sulphur in the soil after the harvest. Elemental sulphur was obtained as a waste material of petroleum refining and was incorporated into a 15-15-15 NPK fertiliser where it comprised 4%. The experiment had the following variants: 1) control (unfertilised); 2) NPK 1; 3) NPK 2; 4) NPKS 1; 5) NPKS 2. The smaller dose amounted to 3.3 g, the higher one to 6.7 g of the fertiliser per pot (6 kg of soil). Moreover all variants were performed in 2 different soils - a medium soil with neutral pH value and a heavy one with alkali pH value. At the stage of 6 true leaves, the content of nitrogen in plants increased in accordance with its dose. Simultaneously, sulphur applied in the NPKS fertiliser improved nitrogen utilization. The difference between the variants fertilised with NPK and the variants with NPKS amounted to 38.9% in the neutral medium soil, whereas in the alkali heavy soil it was as low as 1.4%. The yield of both seed and straw in the fertilised variants was statistically significantly higher than in the unfertilised control variant. However, there were observed no statistically significant differences between the variants with sulphur and the variants without sulphur although both the yield of the seed and straw in the variants with NPKS was higher than in the variants with NPK. The application of elemental sulphur into the neutral medium soil increased the concentration of both nitrogen and sulphur in the mustard seed in comparison with the variants fertilised with NPK only. The difference between them comprises 1.8% and 9.0% in variants with the small and high dose, respectively. In the heavy soil, the trend was opposite. The application of sulphur into both soils resulted in the increase of the oil content in comparison with the NPK variants. Sulphur addition to NPK had a positive impact on the augmentation of the available sulphur content in the soil which can positively affect, particularly the following crops. Still, a drop in the pH value was not confirmed

Wykorzystanie różnych ekstrahentów w celu prognozowania pobierania cynku przez rośliny

The main aim of this work was to compare different extraction agents in order to identify those which are able to give us most reliable data for assessment of soil zinc content and for prediction of possible contamination of crop. In order to compare several extraction methods and to identify the most suitable one for the zinc transfer into plant and to examine behaviour of high doses of a sludge heavily contaminated with zinc (almost 7 000 mg Zn kg–1), a two year pot experiment was established in vegetation hall in 2005. There were chosen five soils with different pH value (from extremely acidic to neutral) and planted with four crops – spinach, carrot, spring wheat and maize. But for control combination there were treatments with lower dose of sludge (equivalent of 5 Mg (tons) of dry matter per hectare) and high dose (equivalent of 25 Mg (tons) of dry matter per hectare for spinach and carrot and 50 Mg (tons) for wheat and maize). Following extraction agents were used for soil analyses – Aqua regia, 2 mol HNO3 dm–3, 0.43 mol HNO3 dm–3, Mehlich III, CAT, DTPA, CaCl2, and NH4NO3. Correlations of soil zinc content measured with particular extracting agents and zinc content in plants were calculated. The best correlations were found with quantity of Zn soluble in weakest extraction agents – CaCl2 and NH4NO3. They correlated with themselves and with zinc content in plans but not with other agents. The rest of agents mostly correlated among 0.43 mol HNO3 dm–3, Mehlich III, CAT and DTPA and between Aqua regia and 2 mol HNO3 dm–3. There were quite tight correlations between soil pH and zinc content in plants confirming that pH is a crucial factor for zinc soil mobility. It implies that knowledge of soil pH and (even) pseudo total zinc content can serve as a sufficient source of information about probable zinc status in the soil. Mehlich III, which is in the Czech Republic widely used for the Agrochemical Soil Testing (evaluation of P, K, Ca and Mg status of soil) can be used as a good screening tool (and perhaps for other microelements). Such use would provide a large scale of data without additional costs.Celem pracy było porównanie różnych ekstrahentów w celu identyfikacji tego, dzięki któremu będzie można uzyskać najbardziej rzetelne dane dla oceny zawartości cynku w glebie i prognozowania możliwości zanieczyszczenia roślin. W celu porównania kilku metod ekstrakcji i rozpoznania najbardziej odpowiadającej pobieraniu cynku przez rośliny oraz zbadania zachowania się dużych dawek osadów silnie zanieczyszczonych cynkiem (prawie 7 000 mg Zn kg-1), w 2005 r. założono dwuletnie doświadczenie wazonowe w hali wegetacyjnej. Wybrano pięć gleb o różnej wartości pH (od bardzo kwaśnych do obojętnych) i uprawiano pięć gatunków roślin - szpinak, marchew, pszenicę jarą i kukurydzę. Kombinacją kontrolną były obiekty z mniejszą dawką osadu (równoważną 5 Mg (tonom) suchej masy na 1 ha) i wysoką dawką (równoważną 25 Mg (tonom) suchej masy na 1 ha pod szpinak i marchew oraz 50 Mg (tonom) pod pszenicę jarą i kukurydzę). W badaniach użyto następujące ekstrahenty: woda królewska, 2 mol HNO3 dm-3, 0,43 mol HNO3 dm-3, Mehlich III, CAT, DTPA, CaCl2 i NH4NO3. Obliczono współczynniki korelacji pomiędzy ilością cynku ekstrahowanego z gleby przez poszczególne ekstrahenty a zawartością cynku w roślinach. Stwierdzono najsilniejszą korelację pomiędzy ilością cynku rozpuszczalnego w najsłabszym ekstrahentach - CaCl2 i NH4NO3. Ilości te były skorelowane ze sobą oraz z zawartością cynku w roślinach, ale nie z ilością cynku rozpuszczalnego w innych ekstrahentach. Ilości cynku ekstrahowane przez pozostałe odczynniki ekstrakcyjne: 0,43 mol HNO3 dm-3, Mehlich III, CAT i DTPA, a także ekstrahowane wodą królewską i 2 mol HNO3 dm-3 były najczęściej skorelowane ze sobą. Stwierdzono dość ścisłe korelacje między pH gleby a zawartością cynku w roślinach potwierdzające, że pH jest kluczowym czynnikiem mającym wpływ na mobilność cynku w glebie. Oznacza to, że znajomość pH gleby i (nawet) zbliżonej do całkowitej zawartości cynku w glebie może służyć jako wystarczające źródło informacji o możliwym statusie cynku w glebie. Odczynnik Mehlich III, który jest szeroko stosowany w Czeskiej Republice w badaniach chemiczno--rolniczych (oceniających stan P, K, Ca i Mg w glebie), może być stosowany jako dobre narzędzie do badań przesiewowych (być może też do innych mikrślementów). Takie jego zastosowanie zapewni dużą liczbę danych bez dodatkowych kosztów

Wpływ materii organicznej i pH na mobilność niektórych metali ciężkich w glebach trwałych użytków zielonych na Pogórzu

In 2008 and 2009 total content of some heavy metals (Zn, Cu, Co, Pb, Cd and Mo) and their water-soluble forms were explored in soils of permanent grasslands of the foothills of the Hruby Jesenik Mts. Relationship between soil reaction and content and quality of organic matter was studied. The total content of heavy metals ranged from 38.40 to 71.65 mg Zn kg–1; 10.47–17.46 mg Co kg–1; 14.30–41.42 mg Cu kg–1; 3.84–15.53 mg Pb kg–1; 0.104–0.323 mg Cd kg–1 and 0.129–0.617 mg Mo kg–1. Content of water-soluble forms ranged from 0.0016 to 1.0100 mg Zn kg–1; 0.0204–0.2605 mg Co kg–1; 0.0085–0.2413 mg Cu kg–1, and 0.0108–0.0485 mg Cd kg–1 of soil. Soil reaction ranged from 4.09 to 5.43 (ie from extremely acid to acid). Results showed that decreasing of pH value caused significant increase of water-soluble fractions of zinc and cobalt content, especially when mineral and organic fertilisers (slurry) were applied. After compost application the inverse relationship water-soluble zinc content and pH was found. Interrelations were not statistically significant in this case. On permanent grassland soils total organic carbon (TOC) content ranged from 0.60 to 2.55 %. Sum of humic substances (HS) ranged from 4.5 to 8.0 mg kg–1; with a 1.5–3.3 mg kg–1 and 2.5–5.5 mg kg–1 proportion of humic acids (HA) and fulvic acids (FA), respectively. Humification degree was low (< 20 %). After organic and mineral fertilizers application on permanent grassland soils statistically significant differences were discovered in TOC and HA (compost) content (between the individual rates of organic fertilisers). Because of FA prevailed in humus fractional composition they mostly contributed to the transformation and migration of heavy metals mobile forms. During the experiment with mineral and organic fertilisers the dependence of water-soluble heavy metals and organic matter content was statistically significant for cobalt and copper. Cobalt content was inversely proportionate to HA content (r = –0.4021). In a similar way the copper content decreased due to increasing of FA in soils (r = –0.3803).W latach 2008-2009 oceniano ogólną zawartość niektórych metali ciężkich (Zn, Cu, Co, Pb, Cd i Mo) oraz ich form wodnorozpuszczalnych w glebach trwałych użytków zielonych Pogórza Hrubý Jeseník. Badano zależności między odczynem gleb i zawartością oraz jakością materii organicznej. Ogólna zawartość metali ciężkich mieściła się w zakresach: 38,40-71,65 mg Zn kg-1; 10,47-17,46 mg Co kg-1; 14,30-41,42 mg Cu kg-1; 3,84-15,53 mg Pb kg-1; 0,104-0,323 mg Cd kg-1 i 0,129-0,617 mg Mo kg-1 gleby. Zawartość form wodnorozpuszczalnych wahała się w granicach: 0,0016 to 1,0100 mg Zn kg-1; 0,0204-0,2605 mg Co kg-1; 0,0085-0,2413 mg Cu kg-1 i 0,0108-0,0485 mg Cd kg-1 gleby. pH gleb wahało się od 4,09 do 5,43 (tj. odczyn od bardzo kwaśnego do kwaśnego). Wykazano, że obniżenie wartości pH powodowało istotny wzrost zawartości frakcji wodnorozpuszczalnych cynku i kobaltu, zwłaszcza gdy zastosowano nawozy mineralne i organiczne (gnojowicę). Po zastosowaniu kompostu stwierdzono odwrotną zależność między zawartością frakcji wodnorozpuszczalnego cynku i pH. Zależności te nie były istotne statystycznie. Całkowita zawartość węgla organicznego (TOC) w glebach trwałych użytków zielonych wahała się od 6,0 do 25,5 g kg-1. Suma substancji humusowych (HS) wahała się od 4,5 do 8,0 mg kg-1; z udziałem odpowiednio 1,5-3,3 mg kg-1 kwasów huminowych (HA) i 2,5-5,5 mg kg-1 kwasów fulwowych (FA). Stopień humifikacji był niski (< 20%). Po zastosowaniu nawozów organicznych i mineralnych na glebach trwałych użytkach zielonych wykazano statystycznie istotne różnice w zawartości TOC i HA (kompost) (między poszczególnymi dawkami nawozów organicznych). Ponieważ FA przeważają w składzie frakcyjnym próchnicy, najczęściej one biorą udział w przemianach i przemieszczaniu się mobilnych form metali ciężkich. W trakcie doświadczenia z nawozami mineralnymi i organicznymi zależność między zawartością frakcji wodnorozpuszczalnych metali ciężkich i materii organicznej była statystycznie istotna dla kobaltu i miedzi. Zawartość kobaltu była odwrotnie proporcjonalna do zawartości HA (r = -0,4021). Podobnie zawartość miedzi obniżała się wraz ze zwiększającą się zawartością FA w glebach (r = -0,3803)

Wpływ nawożenia dolistnego selenem i gotowania na jakość żywieniową ziemniaków

In accurate small-plot experiments with potatoes we explored the effect of foliar applications of Se in the form of sodium selenate (IV) on tuber yields, the Se concentration in the tops and tubers of raw and boiled potatoes and in French fries, in the 'Karin' and 'Ditta' varieties. The experiments were established in Źabčice near Brno in 3 variants: (1) control; (2) 200 g Se o ha^-1; (3) 400 g Se o ha^-1. The mean total yields of tubers per ha were the highest in the control variant (19.99 Mg o ha^-1) but applications of selenium reduced the yields statistically insignificantly (to 16.79 and 18.39 Mg o ha"1, respectively). The 'Ditta' yariety produced higher yields. The average content of Se increased with the applied dose as compared with the control and equals: in the tops 0.255; 0.739 and 0.767 mg o kg^-1 d.m., in raw tubers 0.214; 0.564 and 0.917 mg o kg^-1 d.m., in boiled tubers 0.200; 0.523 and 0.915 mg o kg^-1 d.m. and in French frics 0.223; 0.425 and 0.574 mg o kg^-1 d.m. The content of Se decreased more markedly in French fries by heat processing. On the basis of the achieved results foliar nutrition appears to be a suitable and economically reasonable measure towards a targeted increase in the content of Se in potato tubers from the viewpoint of the positive effects of Se on the human organism.W ścisłym doświadczeniu mikropoletkowym badano wpływ nawożenia dolistnego selenu w formie selenianu(IV) sodu na plony bulw ziemniaków odmian 'Karin' i 'Ditta', zawartość Se w łętach i bulwach ziemniaków surowych i gotowanych oraz we frytkach. Doświadczenia założono w Żab čicach koło Brna w 3 wariantach: (1) kontrola; (2) 200 g Se o ha^-1; (3) 400 g Se o ha^-1. Największe średnie plony bulw uzyskano w obiekcie kontrolnym (19,99 Mg o ha^-1), a stosowanie selenu zmniejszało statystycznie nieznacząco plony (odpowiednio o 16,79 i 1839 Mg o ha^-1). Odmiana 'Ditta' wytwarzała większe plony. Średnia zawartość Se zwiększała się wraz z zastosowaną dawką Se w porównaniu z obiektem kontrolnym i wynosiła w łętach 0,255; 0,739 i 0,767 mg o kg^-1 s.m., w bulwach surowych 0,214; 0,564 i 0,917 mg o kg^-1 s.m., w gotowanych bulwach 0,200; 0,523 i 0,915 mg o kg^-1 s.m. i we frytkach 0,223; 0,425 i 0,574 mg o kg^-1 s.m. Zawartość Se zmniejszała się wyraźniej we frytkach w wyniku obróbki termicznej. Na podstawie uzyskanych wyników można stwierdzić, że nawożenie dolistne wydaje się być odpowiednim i ekonomicznie uzasadnionym sposobem w kierunku osiągnięcia większej zawartości Se w bulwach ziemniaków z punktu widzenia pozytywnego wpływu Se na organizm ludzki

Influence of combined nitrogen and sulphur fertilization on false flax (Camelina sativa [L.] Crtz.) yield and quality

The influence of joint applications of N and S on false flax (Camelina sativa L.) growing was studied in a pot experiment. Nitrogen was applied as NH4NO3 at rates of 0.6 (N1)–0.9 (N2)–1.2 (N3) g per pot. Sulphur was applied as (NH) 2SO4 to achieve levels of 35 ppm (S1) and 55 ppm (S2) S-SO4n 2. The number of branches per plant increased with the nitrogen doses (10.62–12.41–15.38). The N2 and N3 rates (4.91 g and 4.79 g, respectively) significantly increased the seed yields (g/plant) as compared to N1 weight (g) increased significantly only with the highest level of nitrogen N3 (18.23 and 1.17, respectively) compared to N1 (16.52 and 1.06, respectively). Increasing levels of nitrogen (N1–N2–N3) reduced the oil content of seeds (40.79–38.40–37.66%), but increased the protein content (23.93–25.63–28.19%). The level of sulphur S2 significantly stimulated only the oil content to 39.36% compared to 38.54% with S1. At the same time a negative correlation was discovered between the oil and protein content in the seeds (r= −0.8164). The applied doses of nitrogen N total oil yields (1.88–1.80 g/plant) as well as the total protein yields (1.25–1.35 g/plant) compared to N1 (1.53 and 0.90 g/plant, respectively)

THE EFFECT OF UREA AND UREA WITH UREASE INHIBITOR ON THE CONTENT OF MACRONUTRIENTS IN TUBERS AND TOPS OF POTATOES (SOLANUM TUBEROSUM L.)

Abstract MUSILOVÁ, L., LOŠÁK, T., HLUŠEK, J., VÍTĚZOVÁ, M., JŮZL, M., ELZNER, P., FILIPČÍK, R., JŮZL, M., BENNEWITZ, E.: The eff ect of urea and urea with urease inhibitor on the content of macronutrients in tubers and tops of potatoes (Solanum tuberosum L.). Acta univ. agric. et silvic. Mendel. Brun., 2012, LX, No. 5, pp. 167-17

Wpływ mocznika i mocznika z inhibitorem ureazy na plonowanie oraz zawartość azotu i kadmu w ziemniakach

Worldwide the urea fertilisers are the fastest growing and most commonly used source of nitrogen in agriculture. The benefits of using urea as a fertiliser are due to its high nitrogen content (approximately 46 % nitrogen), non polarity, high solubility, and low costs for manufacture, storage, and transport. Among the various available mitigation tools, urease inhibitors like NBPT (N-(n-butyl) thiophosphoric triamide) have the highest potential to improve the efficiency of urea by reducing N losses, mainly via ammonia volatilization. In 2011 and 2012 a small-plot experiment was established with the potato ‘Karin’ variety. The experimental locality was Zabcice, ca 30 km south of Brno, a maize-growing region. Prior to planting both mineral fertilisers (urea and urea with urease inhibitor NBPT – UREA stabil) were applied to the soil surface. During planting these fertilisers were incorporated into the soil. The experiment involved 7 treatments: 54, 72, 90 kgN • ha–1 as urea, 54, 72, 90 kgN • ha–1 as UREA stabil and unfertilised control. Each treatment was repeated 4 times. The focus of the experiment was to monitor the effect of two different fertilisers and different N-doses on the yields of potato tubers and content of nitrogen (N) and cadmium (Cd) in tubers and tops (stems + leaves). In 2011 the contents of nitrogen in the tubers fluctuated between 14.3 and 15.6 g • kg–1 d.m. and in the tops between 29.7 and 40.9 g • kg–1 d.m. The contents of cadmium in tubers ranged between 0.14 and 0.17 mg • kg–1 d.m. and in tops between 0.50 and 0.72 mg • kg–1 d.m. In 2011 the tuber yields fluctuated irregularly, i.e. between 17.0 and 32.9 Mg • ha–1. In 2012 the nitrogen contents in tubers ranged between 16.0 and 17.3 g • kg–1 d.m. and in the tops between 23.9 and 36.9 g • kg–1 d.m. Cadmium contents in tubers fluctuated between 0.13 and 0.20 mg • kg–1 d.m. and in the tops between 0.35 and 0.64 mg • kg–1 d.m. In 2012 the tuber yields fluctuated irregularly between 25.2 and 33.9 Mg • ha–1. Based on the results we can conclude that both fertilisers (urea, UREA stabil) were reflected in the N and Cd contents of the biomass of potatoes irregularly in dependence on the year, rate of fertiliser and analysed plant organ (tubers, tops). In both years the contents of N and Cd were higher in the tops. Tuber yields fluctuated irregularly in dependence on the year and rates of nitrogenous fertilisers.Na całym świecie nawozy mocznikowe są najbardziej dynamicznie rozwijającym się i najczęściej stosowanym źródłem azotu w rolnictwie. Korzyści ze stosowania mocznika jako nawozu wynikają z dużej zawartości azotu (około 46% azotu), jego niepolarności, dobrej rozpuszczalności oraz niskich kosztów produkcji, przechowywania i transportu. Wśród różnych dostępnych narzędzi ograniczania dostępności azotu, inhibitory ureazy, takie jak NBPT (N-(n-butylo) triamid tiofosforowy) mają największy potencjał do poprawy efektywności mocznika poprzez zmniejszenie strat N, głównie przez ulatnianie amoniaku. W latach 2011 i 2012 założono małopoletkowe doświadczenie z ziemniakami odmiany ‘Karin’, zlokalizowane w miejscowości abčice, około 30 km na południe od Brna, w regionie uprawy kukurydzy. Przed sadzeniem zastosowano obydwa warianty nawożenia mineralnego (mocznik i mocznik z inhibitorem ureazy NBPT-UREA stabil) na powierzchnię gleby. W czasie sadzenie nawozy zostały wymieszane z glebą. Doświadczenie obejmowało 7 obiektów: 54, 72, 90 kgN • ha–1 jako mocznik, 54, 72, 90 kgN · ha–1 jako UREA stabil oraz nienawożony obiekt kontrolny, każdy w 4 powtórzeniach. Celem doświadczenia było zbadanie działanie dwóch różnych nawozów i różnych dawek N na wielkość plonu bulw ziemniaka oraz zawartość azotu (N) i kadmu (Cd) w bulwach i łętach (łodygi + liście). W 2011 r. zawartość azotu w bulwach wahała się od 14,3 do 15,6 g • kg–1, a w łętach od 29,7 do 40,9 g • kg–1 s.m. Zawartość kadmu w bulwach wahała się od 0,14 do 0,17 mg • kg–1, a w łętach od 0,50 do 0,72 mg • kg–1 s.m. W 2011 r. plony bulw zmieniały się nieregularnie, tj. od 17,0 do 32,9 t • ha–1. W 2012 r. zawartość azotu w bulwach wahała się od 16,0 do 17,3 g • kg–1, a w łętach od 23,9 do 36,9 g • kg–1 s.m. Zawartość kadmu w bulwach wahała się od 0,13 do 0,20 mg • kg–1, a w łętach od 0,35 do 0,64 mg • kg–1 s.m. W 2012 r. plony bulw zmieniały się nieregularnie, od 25,2 do 33,9 Mg • ha–1. Na podstawie uzyskanych wyników można stwierdzić, że obydwa warianty nawożenia (mocznik, UREA stabil) powodowały nieregularne zmiany zawartości N i Cd w biomasie ziemniaka w zależności od roku, dawki azotu i analizowanego organu rośliny (bulwy, łęty). W obydwu latach łęty zawierały więcej N i Cd niż bulwy. Plony bulw zmieniały się nieregularnie w zależności od roku i dawki nawozów azotowych

The effect of nitrogen and sulphur fertilization on yield and quality of kohlrabi (Brassica oleracea, L.) Efeito da adubagem com o nitrogénio e enxofre ao rédito e à qualidade das couves-rábanos (Brassica oleracea, L.)

In 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 NO3- 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 NO3- content was higher in tubers than in leaves. Increasing the S level in the soil significantly reduced NO3- 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 S0, S1, and S2 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 NO3- contained in the parts used for consumption.<br>Deficiência aguda de S no solo tem sido observada na Europa desde os anos 1980. O couve-rábano é uma das plantas com maior exigência nesse nutriente e sua interação com o N é frequentemente relatada na literatura. Este trabalho foi conduzido em casa de vegetação visando testar o efeito da aplicação de S, na presença de N, na produção e qualidade de couve-rábano (Brassica oleracea, L., variedade Lua). As plantas foram cultivadas em vasos contendo 6 kg de solo, aos quais foram aplicados 0,6 kg de N e S para se obter os teores no solo de: 25 (teor natural), 35, ou 45 mg kg-1. Foram avaliadas a produção e o teor de N, S e NO3- nas raízes e nas folhas e as alterações no teor de aminoácidos nas raízes. A produção de raízes do couve-rábano não afetada pela adubação com S. O teor de N nas raízes e nas folhas variou de 1,42-1,48 % e de 1,21-1,35 % de N, respectivamente, não sofrendo efeito significativo da adubação com S. O teor de S nas raízes oscilou entre 0,59-0,64 % de S. A aplicação de S influenciou positivamente o seu teor no tecido foliar, que apresentou estreita relação com os teores do nutriente no solo, chegando a 0,50; 0,58 e a 0,76 % de S, respectivamente, para os três teores testados. O teor de NO3- foi maior nas raízes do que nas folhas. O aumento das doses de S reduziu o teor de NO3- nas raízes, em 42,2 a 53,6 %, e nas folhas em 8,8 a 21,7 %. O aumento do teor de S no solo reduziu o teor de cisteína + metionina em valores que variaram de 16 a 28 %, mas não afetou os teores de valina, tirosina, ácido aspártico e serina. Com a variação dos teores de S entre 25 e 45 mg kg-1 , houve decréscimo de treonina, isoleucina, leucina, arginina, e a soma de amino ácidos esenciais e alanina na faixa de 37 a 9 %. O teor de histidina aumentou com a elevação do teor de S no solo. A adubação do couve-rábano com S é recomendada sobre tudo para a estabilização da produção e para a redução dos teores de NO3-, cuja presença em alimentos é indesejada