No abstract

A small-plot long-term field fertilization experiment was set up in 2011 with willow (Salix triandra x Salix viminalis ’Inger’) grown as an energy crop in Nyíregyháza, Hungary. The brown forest soil was treated three times (in June 2011, May 2013, May 2016) with municipal biocompost (MBC), municipal sewage sludge compost (MSSC) or willow ash (WA), and twice (June 2011, May 2013) with rhyolite tuff (RT). In late May – early June 2016 urea (U) and sulphuric urea (SU) fertilizers were also applied to the soil as top-dressing (TD). These fertilizers and amendments were also applied to the soil in 2016 in the combinations; MBC+SU, RT+SU, WA+SU and MSSC+WA. All the treatments were repeated four times. In July 2016 the highest nitrogen concentrations in willow leaves were measured in the U (3.47 m/m%) and SU (3.01 m/m%) treatments, and these values were significantly higher than the control (2.46 m/m%). An excess of nitrogen considerably reduced the Zn uptake of the leaves, with values of 39.5 μg g-1 in the U treatment, 53.4 μg g-1 in the SU treatment, and 63.5 μg g-1 in the control. All other amendments or TDs, except for WA, enhanced the specific potassium concentrations in willow leaves compared to the control. No significant quantities of toxic elements (As, Ba, Cd, Pb) were transported from soil amendments or TDs to the willow leaves. In July 2016 the most intensive leaf chlorophyll fluorescence was observed in the MSSC and MSSC+WA treatments.

The effects of a heavy metal containing wastewater sediment on two cultivars of white willow were investigated in a pot experiment. Our aim was to examine the effect of toxic elements on the microanatomical parameters of the leaves of the tested plant. We examined the following parameters: stomatic density, stoma width and length, lamina thickness, adaxial and abaxial epidermis thickness, mesophyll thickness, palisad and spongy parenchyma thickness, main vein width and length. The experiment had the following results: with the presence of toxic elements, the thickness of the lamina increased, within this, there was a significant growth in the thickness of the spongy parenchyma.  The width and the length of the main vein decreased, so did the extent of the xylem cavities. The extent of the collenchymal stock of the leaf venation increased. The number of stomas increased, but the size of the stomas decreased. As a result of toxic element contamination, the number of Ca-oxalate crystals increased within the leaf mesophyll.

A hazánkban az olajipari napraforgó a harmadik legnagyobb területen termesztett szántóföldi növény. A termésátlagok folyamatos növekedése miatt egyre nagyobb jelentőséggel bír az optimális tápanyag-ellátás, azon belül is az optimális nitrogén ellátás. Vizsgálataink arra irányultak, hogy különböző nitrogénformák (karbamid, pétimészsó, pétisó), valamint azok kijuttatási időpontjai (azonos hatóanyag szintek mellett) milyen hatással vannak a növény termésmennyiségére és olajtartalmára. Kísérletünket a Nyíregyházi Egyetem Tangazdaságában, Nyírtelek Ferenc tanyán végeztük el 2020-ban, 2021-ben és 2022-ben. A fenti műtrágyaféleségeket a vizsgált években 80 kg/ha-os hatóanyagmennyiséggel juttattuk ki, egyszeri és osztott kezelést alkalmazva. A kísérleti terület nagysága 0,75 hektár volt kezelésenként, amiből 4 db 1200 m2-es parcella került kijelölésre. A betakarított termésmennyiségeket külön lemértük majd átlagoltuk. Az olajtartalom méréséhez kezelésenként egy-egy mintát vettünk. A három év eltérő eredményeket hozott. A rendkívüli aszály miatt a 2022-es év eredményei nehezen értékelhetők. A 2020-as és a 2021-es évben sem állapíthattunk meg egyértelmű tendenciákat. Az osztott kezelésekkel 2020-ban magasabb termésmennyiségeket mértünk, de a 2021-es év eredményei ezt nem támasztották alá. Olajtartalom szempontjából az osztott kezelések általában jobb eredményt produkáltak, de a különbség statisztikailag nem kimutatható.

Growth chamber pot experiment was set up with two varieties of Sudan grass. Plants were grown in uncontaminated (control) topsoil of the former wastewater settling pond from Debrecen, which was amended with 10% (m/m) of wastewater sediment (P: 5125; Fe: 22756, Pb: 287; Cr: 1027; Zn: 888 mg/kg). The elemental composition of soil and shoots of plants and activities of some enzymes in leaves were measured. It can be concluded that the roots and shoots of plant individuals of both varieties consistently took up higher concentrations of each of the elements from the medium "enriched" with wastewater sediment. The elevated element concentrations were found in some cases in the roots, and in other cases in the leaves (K: ~2000 (soil) - ~13000 (root) - ~30000 (shoot) mg/kg; Cr: ~330 (soil) - ~3,30 (root) - ~0,189 (shoot) mg/kg). The excessive accumulation of toxic elements was not observed. The activities of four enzymes were measured in the leaves of plants (glucose 6-phosphate dehydrogenase, G6PDH; isocitrate-dehydrogenase, ICDH; peroxidase, POX; catalase, CAT). The enzyme activities of POX increased meanwhile that of CAT decreased significantly, in spite of slight differences. As a trend, the specific activity for G6PDH increased by 26% (GK Csaba) and 36% (Akklimat), while values for ICDH became higher by 28% (GK Csaba) and 41.5% (Akklimat), for the two varieties studied, respectively. The latter results were not statistically supported.