Acta Sci. Pol., Agricultura 13(4) 2014, 153-162

Acta Sci. Pol., Agricultura 13(4) 2014, 153-162 THE EFFECT OF DRESSING SEED MATERIAL WITH A HUMUS PREPARATION AND FOLIAR POTASSIUM FERTILIZATION ON THE YIELD AND CHEMICAL COMPOSITION OF SPRING BARLEY GRAIN Edward Wilczewski, Małgorzata Szczepanek, Tomasz Knapowski, Ewa Rosa University of Science and Technology in Bydgoszcz 1 Abstract. The aim of the study was evaluation of the effect of dressing seed material of spring barley with a humus preparation and foliar potassium fertilization with Drakar on its yield and content of nitrogen, phosphorus, potassium and magnesium in the grain. One-way field experiment was carried out in the years 2006-2008, in Chrząstowo (53 09 N; 17 35 E) near Bydgoszcz, on soil classified as mesic Typic Hapludalfs, of a granulometric composition of light sandy loam. The effect of the following was evaluated: humus preparation Humistar (12% humic acids and 3% fulvic acids), used for dressing at a rate of 1 dm 3 per 50 kg of barley grain (1), foliar fertilizer Drakar (25.7% K and 3% N), applied at two doses of 2 dm 3 ha -1, before flowering and after its end (2), as well as the combined application of Humistar and Drakar (3). The results of using Humistar and Drakar were compared with the control (4) where these preparations were not used. A significant increase was found in 1000 grain weight and yield of barley grain under the effect of dressing the seed material with Humistar. However, this factor s effect on spike density per unit of area or on the grain number per spike was not indicated. Foliar fertilizer Drakar did not affect significantly the grain yield or its components. The studied preparations did not affect significantly the leaf greenness index in barley in the stage of tillering, shooting and flowering. However, a positive effect of Humistar was found on values of this index in the milk stage. The total nitrogen concentration in barley grain was independent of the used preparations. However, a significant increase in the content of phosphorus and magnesium was found in barley grain dressed with Humistar. Concentration of phosphorus and potassium in barley grain on plots with a foliar fertilization with Drakar was lower, while of magnesium higher than on the control. Key words: leaf greenness index, macroelements, SPAD, yield components Corresponding author Adres do korespondencji: dr inż. Edward Wilczewski, Department of Plant Cultivation of University of Science and Technology in Bydgoszcz, A. Kordeckiego 20, 85-225 Bydgoszcz, e-mail: edward@utp.edu.pl

154 E. Wilczewski, M. Szczepanek, T. Knapowski, E. Rosa INTRODUCTION Spring barley is a crop of a great economical significance in Poland. It covers app. 8% of sowing area (mean from the years 2010-2012), and is mainly used as a component of pig feed, and as a raw material for brewing industry [GUS 2013]. Its yields are variable over the years. This results from a high sensitivity of this plant to water supplementation in the growing season [Qureshi and Neibling 2009, Żarski et al. 2011, 2013, Liszewski et al. 2012], which is connected with a relatively poorly developed root system [Batalin 1962]. Thus, it is justifiable to look for agrotechnical methods of growth stimulation and for enabling a better use of soil resources by barley. Numerous studies indicate a positive effect of humus preparations on the growth of roots and the aboveground parts of plants [Ayuso et al. 1996a, Cooper et al. 1998, Canellas et al. 2002, Verlinden et al. 2009, 2010, Matysiak et al. 2011, Szczepanek and Wilczewski 2011]. These substances play a fundamental role in developing physical and biological properties of the soil, and they contribute to a faster growth of roots and shoots. Better root system enables the plant to uptake mineral components from the soil more effectively, and thus to produce a higher yield [Verlinden et al. 2009, 2010]. Liquid humus preparations used for dressing the seed material allow for improving plant yield, even if the applied dose is low. Results of previous studies concerning the effect of humus preparations on growth and plant yield are equivocal [Nardi et al. 2002]. Plant s response depends on the source of humus and its chemical composition connected with it [Muscolo et al. 2007], molecular mass [Marino et al. 2008] and dose [Ayuso et al. 1996a]. Feed value of barley depends mainly on the protein content in the grain. First of all, proper supplementation of the plant with nitrogen is favorable for a high concentration of this element. An element which is essential for accumulating protein in the grain is also potassium, which is an activator of enzymes taking part in its synthesis [Lityński and Jurkowska 1982]. The aim of the study was evaluation of the effect of dressing seed material of spring barley with a humus preparation and foliar potassium fertilization on its yield and content of nitrogen, phosphorus, potassium and magnesium in the grain. In the research hypothesis it was assumed that a positive effect of humus preparation on root development, and of potassium on plant water relations, would improve the condition of the plant supply with nutrients and water, which would cause an increase in the yield and/or nutrient concentration in the grain. MATERIAL AND METHODS One-way field experiment was carried out in the years 2006-2008, in Chrząstowo (53 O 09 N; 17 O 35 E) near Bydgoszcz, on soil classified as mesic Typic Hapludalfs (Soil Survey Staff, 2010), bonitation class IIIa, of granulometric composition of sandy loam. It is characterized by a neutral reaction, average content of organic carbon, and a high content of available potassium and a very high content of available phosphorus and magnesium (Table 1). A significant organic matter fraction is dissolved organic matter ( DOM), whose content is expressed as dissolved organic carbon ( DOC) and/or as dissolved nitrogen (DNt). The studied soil was characterized by a low content of DOM, while an average proportion of DOC and DNt was: 0.64 % C ORG and 0.67 % N TOT, respectively. Acts Sci. Pol.

The effect of dressing... 155 Table 1. Chemical properties of arable layer of the soil (0-30 cm) Tabela 1. Właściwości chemiczne warstwy ornej gleby (0-30 cm) Year Rok C ORG g kg -1 N TOT N OG g kg -1 DOC* mg kg -1 DNt** mg kg -1 P mg kg -1 K mg kg -1 Mg mg kg -1 ph in 1M KCl 2006 7.87 0.87 48.2 4.32 126.4 167.5 94.0 6.60 2007 8.11 0.92 60.3 7.00 151.2 180.0 103.2 6.54 2008 8.10 0.90 45.3 6.73 240.7 207.5 82.8 6.98 Mean Średnia 8.03 0.90 51.3 6.02 172.8 185.0 93.3 6.71 * dissolvedorganic carbon ekstrahowalny węgiel organiczny ** dissolved nitrogen ekstrahowalny azot The experiment was carried out in a randomized block design, in four replications. Plot harvest area was 16.6 m 2. The experimental factor was type of preparation used in spring barley cultivation. The effect of humus preparation Humistar, foliar fertilizer Drakar and their combined application was compared with the control, where no preparations were used. Humistar is an extract from leonardite highly oxygenated form of brown coal from Canada [Verlinden et al. 2010]. It is characterized by black colour and acidic reaction. It contains gravimetrically 12% humic acids and 3% fulvic acids. Preparation was used at a dose of 1 dm 3 per 50 kg grain. The seed material was placed in a seed dresser filled with Humistar, and it was mixed for 5 minutes. Drakar is a liquid fertilizer containing 25.7% K and 3% N. It was foliarly applied in two doses: in -1 mid-june (before flowering BBCH 58-59) and 2 weeks later (BBCH 68-69). 2 dm 3 ha of fertilizer dissolved in 200 dm 3 of water were used each time. On plot with a combined application of both preparations, they were used in the same way as on plots with only Humistar or Drakar. Spring barley Mauritia was used for the studies. Seed grain, before covering it with Humistar, was dressed with a fungicide (tiuram + carbendazim) at a dose of 200 g per 100 kg grain. Barley was sown in early April, with row spacing of 11 cm, at a depth of 2-4 cm. In autumn, in the year before sowing barley, phosphorus and potassium were used at a dose of 21.8 kg ha -1 P and 66.4 kg ha -1 K. Fertilizers were mixed with soil with the use of pre-winter ploughing. Nitrogen was used in spring in two doses: 40 kg ha -1 N before sowing barley, and 50 kg ha -1 N in the stage of shooting in barley (BBCH 31-32). At the same time, also foliar fertilizer, Insol 3, was used at a dose of 1 dm 3 ha -1. Emerging weeds were controlled with the preparation Granstar 75 WG (tribenuron methyl 75%) at a dose of 20 g ha -1 with an addition of preparation Trend 90 EC in the stage of tillering in barley (BBCH 21-22). Fungal diseases were controlled with the use of preparation Bumper 250 EC (propiconazole 25.1%) in late May at a dose of 0.5 dm 3 ha -1, as well as Amistar 250 EC + Artea 330 EC (azoxystrobin 250 g dm -3 + propiconazole 250 g dm -3 + cycloconazole 80 g dm -3 ) in early June at a dose of 0.8 + 0.5 dm 3 ha -1, respectively. Pests (cereal aphid Sitobion avenae F. and cereal leaf beetle Lema melanopus L.) feeding on barley were controlled with preparations: Bi 58 Nowy 400 EC (dimethoate 37.4%) at a dose of 0.5 dm 3 ha -1 and Nurelle D 550 EC (chlorpyrifos 500 g dm -3 ) at a dose of 0.6 dm 3 ha -1. In spring barley s growing season, measurements of leaf greenness index (SPAD) were conducted with the use of a chlorophyll meter SPAD-502. The measurements were carried out on the youngest leaves of 30 plants from each plot in the following developmental stages in barley: tillering (BBCH 22-23), shooting (BBCH 31-32), Agricultura 13(4) 2014

156 E. Wilczewski, M. Szczepanek, T. Knapowski, E. Rosa flowering (BBCH 64-65) and milk stage (BBCH 73-75). Before harvesting barley, spike number [spike m -2 ] was determined. 20 spikes were collected randomly from each plot, and the grain number per spike was determined. After harvest, grain yield was determined in barley. Barley was harvested with a combine harvester in the stage of full maturity (BBCH 91-92) in early August. During harvest, from each plot grain samples were collected, in which moisture was determined, as well as 1000 grain weight, and the content of macroelements. Grain yield was calculated for 15% moisture. Before carrying out chemical analyses the grain was ground. Mineralization was carried out through wet combustion of crushed material with perhydrol and sulphuric acid. Analyses were conducted with the following methods: total nitrogen content with Kjeldahl method; phosphorus content with vanadium-molybdenic method; potassium and calcium with flame photometry; magnesium content with colorimetric method with titan yellow. Chemical analyses were conducted with the use of devices bought as part of the project Realization of the 2 nd Stage of the Regional Innovation Centre co- -funded from the European Regional Development Fund as part of the Regional Operational Programmme for the Kuyavian-Pomeranian Voivodeship for 2007-2013. The obtained results were subjected to analysis of variance with the use of a computer program AWAR, developed by the Institute of Soil Science and Plant Cultivation (IUNG) in Puławy. Significance of differences was determined with Tukey s range test on the significance level of P = 0.05. Analysis of correlations between macroelement content per grain and the grain yield was carried out with the use of a program Statistica for Windows. RESULTS AND DISCUSSION Air temperature in spring barley s growing season was significantly diversified in particular years (Table 2). The least favorable thermal conditions occurred in 2006, in which the cool March and early April caused delay in sowing barley. Furthermore, high temperatures and low rainfall in July in that year resulted in poorer grain development than in other years. In 2007 air temperatures in the period from March to June were higher than long-term means. In 2008 air temperature in the growing season of spring barley was similar to the long-term mean for the area of research. In the study period, high diversification was observed in the amount and distribution of rainfall in particular years. In 2006 there occurred a deficiency in rainfall in June and July, while in 2008 in May and June. In 2007 rainfall from May to July was higher than the totals regarded as optimum for spring barley [Dzieżyc et al. 1987, Panek 1987]. As a result, the obtained grain yields were the highest in 2007, and the lowest in 2008 (Table 3). In 2006 a significant increase in barley s grain yield was found under the effect of the combined application of Humistar and Drakar, compared with the control. However, statistically, no effect of any combination of the applied preparations was proved on barley yield in 2007 and 2008. The obtained results indicate a dependence of the effects of using studied preparations on weather conditions in the growing season. The best results were obtained in the year characterized by an abundant rainfall in May and by a reduced rainfall in June and July (2006). Under these conditions, the application of Humistar with Drakar resulted in the yield increase by 6.4% compared with the control. The lowest effect of applying these preparations was obtained in 2007, which was characterized by a high rainfall in May-July. Acts Sci. Pol.

The effect of dressing... 157 Table 2. Temperature and precipitations during growing season of spring barley Tabela 2. Temperatura i opady w okresie wegetacji jęczmienia jarego Month Miesiąc 2006 2007 2008 Mean from Średnia z lat 1980-2008 Mean air temperature Średnie temperatury powietrza, o C March Marzec -0.9 5.5 3.1 2.7 April Kwiecień 7.8 9.9 8.0 8.3 May Maj 12.8 14.3 13.7 14.0 June Czerwiec 17.2 18.2 17.3 16.8 July Lipiec 22.6 18.0 18.9 19.1 Mean March-July Średnia marzec lipiec 11.9 13.2 12.2 12.2 Total precipitation Sumy opadów atmosferycznych, mm March Marzec 21.6 55.2 53.5 35.0 April Kwiecień 60.4 16.6 40.0 29.6 May Maj 67.4 83.5 13.8 47.4 June Czerwiec 14.6 111.7 19.6 67.6 July Lipiec 28.5 88.9 65.0 70.7 Total March-July Suma marzec lipiec 192.8 355.9 191.9 250.3 Table 3. Yield of spring barley grain, Mg ha -1 Tabela 3. Plon ziarna jęczmienia jarego, Mg ha -1 Treatment Obiekt 2006 2007 2008 Mean from Średnia z lat 2006-2008 Humistar Humistar + Drakar 5.78 ab 5.85 a 7.47 7.38 4.33 4.32 5.86 a 5.85 a Drakar 5.62 ab 7.42 4.11 5.72 ab Control Kontrola 5.50 b 7.33 4.11 5.65 b Mean Średnia 5.69 7.40 4.22 a, b, c mean values followed by different letters in columns differ significantly with P = 0.05 średnie oznaczone różnymi literami w obrębie kolumn różnią się istotnie dla P = 0.05 On average, from the three years of research, a positive effect of Humistar alone was indicated, as well as of its combined application with Drakar, on the grain yield of spring barley (Table 3). However, the effect of Drakar alone on the yield was not proved. After using humus preparation, increase in the grain yield in barley was on average 0.21 Mg ha -1. Humistar s positive effect on 1000 grain weight of spring barley was indicated, though there was no significant effect of the studied preparations on spike density per unit of area nor on the grain number per spike (Table 4). The positive effect of humus preparations on barley s growth and yield is also presented in other studies. From earlier laboratory studies it follows that dressing seed grain with Humistar had a positive effect on the dynamics of growth of roots and shoots in spring barley as early as in its germination stage [Szczepanek and Wilczewski 2011]. On the other hand, from the research of Ayuso et al. [1996b] it follows that humus substances enable significant increase in barley s uptake of nutrients (nitrogen and phosphorus) from the soil, and thus they contribute to an increase in the grain yield. Agricultura 13(4) 2014

158 E. Wilczewski, M. Szczepanek, T. Knapowski, E. Rosa Table 4. Yield components of spring barley Tabela 4. Elementy strukturalne plonowania jęczmienia jarego Year Rok 2006 2007 2008 Means for Średnie z lat 2006-2008 Treatment Obiekt Number of spikes per 1 sq.m Liczba kłosów na m 2 821 723 533 Number of grains per spike Liczba ziaren w kłosie 21.6 19.0 16.0 1000 grain weight Masa 1000 ziaren g 36.3 48.4 51.9 Humistar 700 19.1 45.9 a Humistar + Drakar 701 18.8 45.8 ab Drakar 683 18.9 45.4 ab Control Kontrola 684 18.8 45.1 b Mean Średnia 692 18.9 45.5 Value of the leaf greenness index (SPAD) may be a measure of the level of plant nutrition with nitrogen [Fotyma and Bezduszniak 2000]. In our own studies, the application of humus preparation and foliar potassium fertilizer did not significantly affect the leaf greenness index in the stage of tillering, shooting or flowering (Table 5). However, significantly higher values of this index were observed on plots with Humistar, compared with the control in the milk stage of barley. The obtained results are in line with the response of barley s yield components to the use of Humistar. This preparation did not affect plant nutrition with nitrogen in the period from tillering to flowering in barley, therefore no improvement in the value of traits formed in that period was found (spike density and grain number per spike). However, capacity of the root system to supply plants with nitrogen increased, which resulted in an increase in 1000 grain weight. Table 5. Leaf greenness index values (SPAD) in particular growth stages of barley means for 2006-2008 Tabela 5. Wartości indeksu zieloności liścia (SPAD) w poszczególnych fazach rozwoju jęczmienia średnie z lat 2006-2008 Treatment Obiekt Developmental stage of spring barley Faza rozwojowa jęczmienia jarego tillering krzewienie (BBCH 22-23) shooting strzelanie w źdźbło (BBCH 31-32) flowering kwitnienie (BBCH 64-65) milk maturity dojrzałość mleczna (BBCH 73-75) Humistar 37.1 40.1 41.9 41.0 a Humistar + Drakar 38.0 40.1 41.7 40.6 ab Drakar 37.3 39.8 42.0 40.4 b Control Kontrola 37.3 40.5 41.9 40.4 b Mean Średnia 37.4 40.1 41.9 40.6 a, b, c mean values followed by different letters in columns differ significantly with P = 0.05 średnie oznaczone różnymi literami w obrębie kolumn różnią się istotnie dla P = 0.05 Values of SPAD index increased in the period from tillering to flowering in barley, then they decreased. Similar changes in the value of this parameter, though of higher intensity, were observed in the studies of Liszewski et al. [2012]. In our own studies, we found no significant effect of Humistar on the total nitrogen concentration in barley grain (Table 6). However, this preparation caused increase in the Acts Sci. Pol.

The effect of dressing... 159 content of phosphorus and magnesium. Concentration of these elements in barley grain on plots with foliar fertilization with Drakar and on the control was significantly lower than on plots where seed grain was dressed with humus preparations. Potassium content in barley grain decreased significantly under the effect of the studied preparations. It was the lowest in barley grain on the plot with Humistar. Table 6. Content of macronutrients in spring barley grains, g kg -1 (means for 2006-2008) Tabela 6. Zawartość makroskładników w ziarnie jęczmienia jarego, g kg -1 (średnie z lat 2006- -2008) Treatment Obiekt NTOT NOG P K Mg Humistar 18.3 3.97 a 3.04 d 1.88 a Humistar + Drakar 18.8 3.93 b 3.06 c 1.87 a Drakar 18.9 3.89 c 3.10 b 1.83 b Control Kontrola 18.9 3.92 b 3.12 a 1.76 c Mean Średnia 18.7 3.93 3.08 1.84 a, b, c mean values followed by different letters in columns differ significantly with P = 0.05 średnie oznaczone różnymi literami w obrębie kolumn różnią się istotnie dla P = 0.05 Different results were obtained by Asik et al. [2009] in their studies on wheat. They found a positive effect of humus preparations applied into the soil on nitrogen uptake in wheat. In the research of Knapowski et al. [in the press], concerning the effect of Humistar and Drakar on the yield and development of quality traits in spring wheat, a positive influence of both studied preparations was found (especially of Drakar) on the total nitrogen concentration in the grain, with a simultaneous absence of this factor s effect on the grain yield. Different response of spring wheat and spring barley to dressing the seed with a humus preparation may be connected with a different grain structure. From the laboratory studies of Szczepanek and Wilczewski [2011] it follows that husked barley grain responds better to soaking in humus preparation than wheat grain. This manifested itself in the stimulation of the initial plant growth, measured with the rate of elongating radicles and hypocotyls in barley, which could be favorable for an increase in this plant s yield. Weaker, though beneficial, effect of humus preparation on the initial growth of wheat seedlings did not translate into an increase in the yield, but into an improvement in grain quality parameters. Despite cultivating barley on fertile soil, rich in minerals, our own studies indicated usefulness of applying humus preparations through soaking the seed material in them for improvement in the yield and concentration of some macroelements in the grain. Grain yield of spring barley was positively correlated with the phosphorus content in it, and negatively correlated with the nitrogen content (Table 7). No dependence between grain yield and the content of potassium and magnesium in the grain was indicated. Phosphorus content in the grain was positively correlated with the potassium content and negatively with nitrogen content. No connection between magnesium content in the grain and values of other traits was indicated. On all dates of measurement, the leaf greenness index was positively correlated with nitrogen content and negatively correlated with the phosphorus content in barley grain (Table 8). Potassium content in the grain was negatively correlated with the leaf greenness index in the stage of tillering, shooting and flowering, while magnesium content in the grain was not correlated with this index. Agricultura 13(4) 2014

160 E. Wilczewski, M. Szczepanek, T. Knapowski, E. Rosa Table 7. Simple correlation coefficients for the relation between the yield of spring barley and concentration of macronutrients in grains (n = 12) Tabela 7. Współczynniki korelacji prostej dla zależności pomiędzy plonem ziarna i zawartością makroskładników w ziarnie (n = 12) Variable Zmienna Grain yield Plon ziarna Concentration of macronutrients in grain Zawartość makroskładników w ziarnie N TOT N OG P K N TOT N OG -0.851* P K 0.594* -0.080-0.829* -0.426 0.579* Mg -0.420 0.510-0.308-0.373 * significant for P = 0.05 istotne dla P = 0,05 Table 8. Simple correlation coefficients for the relation between the leaf greenness index values and concentration of macronutrients in grains (n = 12) Tabela 8. Współczynniki korelacji prostej dla zależności pomiędzy indeksem zieloności liścia i zawartością makroskładników (n = 12) Feature Cecha Leaf greenness index values (SPAD) in particular growth stages of barley Indeks zieloności liścia (SPAD) w poszczególnych fazach rozwoju jęczmienia tillering krzewienie (BBCH 22-23) shooting strzelanie w źdźbło (BBCH 31-32) flowering kwitnienie (BBCH 64-65) milk maturity dojrzałość mleczna (BBCH 73-75) N TOT N OG 0.948* 0.750* 0.662* 0.863* P K -0.872* -0.612* -0.811* -0.770* -0.784* -0.925* -0.579* 0.016 Mg 0.525 0.273 0.354 0.504 * significant for P = 0.05 istotne dla P = 0,05 CONCLUSIONS 1. Dressing seed material with a humus preparation Humistar, and combining this treatment with an additional foliar application of potassium fertilizer Drakar, was found to have a positive effect on the grain yield in spring barley. 2. Dressing seed material with a humus preparation caused a significant increase in 1000 grain weight of spring barley, however it had no effect on spike density and grain number per spike. 3. Foliar potassium fertilizer Drakar had no effect on the grain yield or on yield components in spring barley. 4. After Humistar application, barley contained significantly more phosphorus and magnesium in the grain, compared with the control and with the plot with foliar fertilization of Drakar. However, no effect of the studied preparations was found on the total nitrogen concentration in barley grain. 5. The studied preparations did not affect the leaf greenness index (SPAD) in the stage of tillering, shooting and flowering in barley, but in the milk stage this index was higher after using Humistar, compared with the control and plot with Drakar only. Acts Sci. Pol.

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162 E. Wilczewski, M. Szczepanek, T. Knapowski, E. Rosa Żarski J., Dudek S., Kuśmierek-Tomaszewska R., 2011. Wpływ deszczowania i nawożenia azotem na plonowanie jęczmienia browarnego na glebie lekkiej. Infrastruktura i Ekologia Terenów Wiejskich 3, 69-78. Żarski J., Dudek S., Kuśmierek-Tomaszewska R., Błażewicz J., Zembold-Guła A., 2013. Ocena wpływu deszczowania i nawożenia azotem na wysokość i jakość plonu dwóch odmian jęczmienia browarnego. Infrastruktura i Ekologia Terenów Wiejskich 2/I, 77-92. WPŁYW ZAPRAWIANIA MATERIAŁU SIEWNEGO PREPARATEM HUMUSOWYM I DOLISTNEGO NAWOŻENIA POTASEM NA WIELKOŚĆ PLONU I SKŁAD CHEMICZNY ZIARNA JĘCZMIENIA JAREGO Streszczenie. Celem badań była ocena wpływu zaprawiania materiału siewnego jęczmienia jarego substancją humusową oraz nawożenia dolistnego nawozem potasowym Drakar na jego plonowanie oraz zawartość azotu, fosforu, potasu i magnezu w ziarnie. Ścisłe, jednoczynnikowe doświadczenie polowe wykonano w latach 2006-2008, w Chrząstowie (53 09 N; 17 35 E) koło Bydgoszczy, na glebie brunatnej właściwej, o uziarnieniu gliny lekkiej pylastej. Oceniano wpływ: preparatu humusowego Humistar (12% kwasów huminowych i 3% kwasów fulwowych), stosowanego do zaprawiania w ilości 1 dm 3 na 50 kg ziarna jęczmienia (1), nawozu dolistnego Drakar (25.7% K i 3% N), aplikowanego w dwóch dawkach po 2 dm 3 ha -1, przed kwitnieniem i po jego zakończeniu (2), oraz łącznego stosowania Humistaru i Drakaru (3). Efekty stosowania Humistaru i Drakaru porównywano z kontrolą (4), w której nie stosowano tych preparatów. Stwierdzono istotne zwiększenie masy 1000 ziaren i plonu ziarna jęczmienia pod wpływem zaprawiania materiału siewnego Humistarem. Nie wykazano jednak wpływu tego czynnika na obsadę kłosów z jednostki powierzchni ani liczbę ziaren w kłosie. Nawóz dolistny Drakar nie wpływał istotnie na plon ziarna i jego komponenty. Badane preparaty nie wpływały istotnie na wskaźnik zieloności liści jęczmienia w okresie krzewienia, strzelania w źdźbło i kwitnienia. Stwierdzono natomiast pozytywny wpływ Humistaru na wartości tego wskaźnika w okresie dojrzałości mlecznej. Koncentracja azotu ogólnego w ziarnie jęczmienia nie była zależna od stosowanych preparatów. Stwierdzono natomiast istotne zwiększenie zawartości fosforu i magnezu w ziarnie jęczmienia zaprawianego Humistarem. Koncentracja fosforu i potasu w ziarnie jęczmienia w obiektach z nawożeniem dolistnym Drakarem była mniejsza, a magnezu większa niż w kontroli. Słowa kluczowe: elementy plonowania, indeks zieloności liścia, makroskładniki, SPAD Accepted for print Zaakceptowano do druku: 27.10.2014 For citation Do cytowania: Wilczewski E., Szczepanek M., Knapowski T., Rosa E., 2014. The effect of dressing seed material with a humus preparation and foliar potassium fertilization on the yield and chemical composition of spring barley grain. Acta Sci. Pol., Agricultura 13(4), 153-162. Acts Sci. Pol.