Changes of weed ecological groups under different organic mulches

The aim of the investigation was to evaluate the influence of different organic mulches and different thickness of mulch layer on weed ecological groups. The field experiment was carried out in the Pomological Garden of the Aleksandras Stulginskis University (54º53'N, 23º50'E). The soil type was Calc(ar)i-Endohypogleyic Luvisol (LVg-n-w-cc). Treatments of the experiment: factor A – mulching: 1) without mulch, 2) straw, 3) peat, 4) sawdust, 5) grass; factor B – thickness of the mulch layer: 1) 5 cm, 2) 10 cm.All investigated organic mulches decreased weed density by 2.7–10.3 times compared with non-mulched soil. The mulch layer of 10 cm thickness decreased the weed density better by 1.3–2.9 times compared with the 5-cm mulch layer. The highest amount of weeds belonged to species indifferent to soil pH, rich in nitrogen, moderately moist and moist soil. Organic mulches, not infected with weed seeds, decreased density of the mentioned weed ecological groups compared with no-mulching. On that score mulching with 10 cm thickness mulch layer was more effective than that with 5 cm thickness mulch layer. Qualitative distribution of weeds into ecological groups influenced by mulch and thickness of mulch layer was even, but the quantitative distribution was uneven.Key words: Ecological group, organic mulch, thickness of mulch layer, weedÄnderungen innerhalb ökologischer Gruppen von Unkräutern unter verschiedenem organischen MulchZusammenfassungZiel der Untersuchungen war die Bewertung des Einflusses von unterschiedlichem organischen Mulch bei unterschiedlicher Dicke der Auflagen auf die Verunkrautung. Die Untersuchungen wurden in den Jahren 2004 bis 2009 im Pomologischen Garten von der Aleksandras Stulginskis Universität (54º53'N, 23º50'E) durchgeführt. Die Bodenart war Calc(ar)i-Endohypogleyic Luvisol (LVg-n-w-cc). Die Versuchsvarianten waren: Faktor A – organischer Mulch: 1) ohne Mulch, 2) Winterweizenstroh, 3) Torf, 4) Sägemehl, 5) Gras; Faktor B – Mulchschichtdicke: 1) 5 cm, 2) 10 cm.Alle angewandten Mulchverfahren reduzierten die Unkrautdichte um das 2,7- bis 10,3-Fache im Vergleich mit nicht mit Mulch bedeckten Flächen. Mulchauflagen von 10 cm reduzierten die Unkrautdichte um den Faktor 1,3-2,9 im Vergleich mit Auflagen von 5 cm Mulch. Die höchste Unkrautdichte fand sich bei Boden-pH-, Stickstoff- und Feuchte-toleranten Unkrautarten. Organischer Mulch, nachweislich frei von Unkrautsamen, reduzierte in allen Fällen die Dichte der in Frage stehenden ökologischen Unkrautgruppen im Vergleich mit Flächen ohne Mulchauflage. In dieser Hinsicht waren 10 cm Mulchauflage in allen Fällen besser als nur 5 cm Mulchauflage. Die qualitative Verteilung innerhalb der ökologischen Gruppen der Unkräuter war unabhängig von Mulchart oder Dicke der Auflage immer ausgeglichen. Nicht ausgeglichen hingegen war die quantitative Verteilung.Stichwörter: Mulchschichtdicke, ökologische Gruppen, organischer Mulch, Unkrau

Control of Heracleum sosnowskyi in Lithuania

Sosnovsky’s hogweed (Heracleum sosnowskyi) is a dangerous perennial, invasive alien plant in Lithuania. Control of this plant is complicated due to well-developed biological properties. To achieve efficient control of the species, it is crucial to choose highly efficient herbicides and their combinations. Field experiments, designed to compare the efficacy of different herbicides and their mixtures used to control Heracleum sosnowskyi, were conducted in 2016 and 2017 in Lithuania, Varnupiai (54° 29' 19.54", 23° 30' 45.9"), Marijampolė distr. The efficacy of the herbicides and their mixtures applied for Sosnovsky’s hogweed control was different. The use of both lower and higher rates of glyphosate did not have the expected result, as 4-6 weeks after application new plants started to emerge. A mixture of glyphosate with triasulfuron showed better effect. The efficacy of dicamba and its mixtures with fluroxypyr and triasulfuron, fluroxypyr, triasulfuron and their mixture, fluroxypyr + clopyralid + MCPA mixture depended on the experimental years’ meteorological conditions. In 2017, the effect of the above mentioned herbicides and their mixtures on Sosnovsky’s hogweed stood out 4-6 weeks after application. Both the smaller and higher rates of tribenuron-methyl + metsulfuronmethyl mixture gave effective control of Sosnovsky’s hogweed. The effect of fluroxypyr + metsulfuron-methyl mixture was more rapid, and 6 weeks after application only single plants remained in the plots

FUNGI AND MYCOTOXINS IN FRESH BEE POLLEN

The aim of the present study was to determine the concentration of microscopic fungi and selected mycotoxins in fresh bee pollen, stored for different periods. In the study, 12 pollen samples collected from the same apiary families were investigated. The total count of microorganisms in the pollen during the study period varied from 2.9×103 to 4.4×103 cfu g-1. The moisture content of fresh pollen varied between 14.2 and 22.7%. During studies, the most prevalent fungal genera of Fusarium, Penicillium, Alternaria, Mucor and yeast were found in fresh bee pollen. The amounts of microscopic fungi increased from 2.9×103 to 4.4×103 cfu g-1 as the pollen storage time increased. The significantly higest amounts of fungal colonies was determined after 3 days storage of undried pollen. The most significant Fusarium spp. increase (14.9%) was determined after 2 days of storage. The highest levels of mycotoxins ZEN and DON were determined after 3 days of pollen storage. Fresh bee pollen chould be dried as quickly as possible, to reduce the levels of microbial contamination

Weed Control by Organic Mulch in Organic Farming System

Vytauto Didžiojo universitetasŽemės ūkio akademij

The effect of mulches on Elytrigia repens spreading under conditions of organic agriculture

Elytrigia repens is the most important and widely spread perennial weed in Lithuania. Infestation with E. repens in organic agriculture is an increasing problem in many parts of Europe. Non-chemical weed management strategies against E. repens, based on cultivation tactics and different mulching, have received very high attention for many years. The two factor stationary field experiment was carried out at the Experimental Station of the Aleksandras Stulginskis University. The influence of organic mulches and different thickness of mulch layer on weed density was investigated in 2004–2009, the residual effect of the mulches and mulch layer was studied in 2010–2012.At the beginning of the experiment higher density of E. repens was estimated in plots with straw mulch and lower in plots mulched with peat and grass mulch. In 2007–2009 all investigated organic mulches reduced E. repens emergence. Peat, sawdust and grass had the strongest influence on the decrease of E. repens regrowth. Significantly higher density of E. repens sprouts was estimated in experimental plots mulched with 5 cm mulch layer compared with this in plots mulched with 10cm mulch layer during 2004–2009 except 2007. The residual effect of all examined organic mulches on E. repens spreading was unequal. The previously six years used and incorporated organic mulches did not significantly decrease E. repens numbers in 2010–2012 because they do not mechanically suppress weed emergence. The residual effect of mulch layers on E. repens sprout numbers was not significant. A tendency of decreased densities of E. repens was estimated during the first two years of the mulch residual effect studies. Einfluss von Mulch auf die Elytrigia repens-Ausbreitung im ökologischen LandbauElytrigia repens ist das wichtigste und am weitesten verbreitete mehrjährige Unkraut in Litauen. Befall mit E. repens in der ökologischen Landwirtschaft ist ein zunehmendes Problem in vielen Teilen Europas. Nichtchemische Managementstrategien gegen E. repens, basierend auf ackerbaulichen Maßnahmen und verschiedenen Mulch-Verfahren, haben eine sehr hohe Aufmerksamkeit seit vielen Jahre erhalten. Der Zwei-Faktoren Feldversuch wurde auf der Versuchsstation der Aleksandras-Stulginskis-Universität durchgeführt. Der Einfluss organischer Mulche und unterschiedlicher Dicke der Mulchschicht auf die Unkrautdichte wurde in 2004-2009 untersucht, und im Zeitraum 2010-2012 wurde die Nachwirkung der Mulchauflagen und der Mulchschichtstärken erfasst.Zu Beginn des Experiments traten höhere Dichten von E. repens in Parzellen mit Strohmulch auf, schwächer in Parzellen mit Torf und Grasmulch. In 2007-2009 reduzierten alle angewandten Mulchverfahren die Entwicklung von E. repens. Torf, Sägemehl und Gras hatten den stärksten Einfluss auf die Abnahme von E. repens. Deutlich höhere Dichten von E. repens wurden auf Versuchsflächen mit 5 cm Mulchauflage im Vergleich mit 10 cm Auflage in den Jahren 2004 bis 2009, außer 2007, festgestellt.Die Nachwirkung aller untersuchten organischen Mulchauflagen auf die Entwicklung von E. repens war unterschiedlich. Die vor 6 Jahren ausgebrachten organischen Mulchauflagen verringerten die Dichte von E. repens im Zeitraum 2010-2012 nicht signifikant, weil sie das Unkraut nicht mechanisch unterdrücken. Die Nachwirkung der Mulchauflagen auf die Dichte von E. repens war nicht signifikant. Eine Tendenz verringerter Dichte von E. repens wurde während der ersten zwei Jahre der Mulch-Nachwirkungs-Studien beobachtet

ECONOMICAL EVALUATION OF REDUCED INTENSITY TILLAGE SYSTEMS, STRAW AND GREEN MANURE COMBINATIONS

Since 1999, a long-term field experiment has been done at the Experimental Station of Vytautas Magnus University (former Aleksandras Stulginskis University) at 54º52′50 N latitude and 23º49′41 E longitude. The soil of the experiment site is Epieutric Endocalcaric Endogleyic Planosol (Endoclayic, Aric, Drainic, Humic, Episiltic) according to WRB (2014). The objective of our investigations was to assess the long-term impact of reduced intensity tillage systems, straw and green manure combinations on productivity and economical evaluation. A short crop rotation was introduced: winter wheat, spring barley, spring rape. The results were obtained in 2000-2017. Sustainable agroecosystems are able to maintain their condition, productivity and biodiversity, as well as their integrity over time and in the context of human activity and use. The sustainability of agroecosystems is inseparable from the stability of their productivity. In order to illustrate this, we estimated crop productivity differences % from the year 2000 to 2017. In terms of crop productivity, all the tested long-term complex measures of different intensities were similar, both when comparing with average productivity that year and when estimating cumulative differences com-pared with deep ploughing. &nbsp

Impact of sustainable tillage on biophysical properties of Planosol and on faba bean yield

Decreased tillage intensity can contribute to a reduced agro-technological footprint and stabilise the negative impact of climate change, especially in leguminous crop cultivation. For this reason, a long-term (since 1988) stationary field experiment has been performed on silty loam Planosol (in Lithuania). The main objective of this study was to establish the influence of sustainable tillage and no-tillage systems on soil aggregate stability to water, penetration resistance, enzymatic activity, abundance of earthworm and faba bean grain yield. Five different tillage systems were investigated: conventional deep and shallow mouldboard ploughing, deep chiselling, shallow disking and no-tillage. No-tillage in faba bean cultivation significantly increased soil structural stability by 40–97%, saccharase content by 0.7–2.0 times, urease activity by 3–4 times, the average quantity of earthworm by 55% and the biomass by 3.6 times. The impact of other ploughless tillage systems on soil properties was positive but not as significant. Faba bean grain yield was more influenced by growing seasons than by different tillage methods

Investigation of soil bioactivity and weed infestation in spring oilseed rape agrocoenosis of different density

Investigation of soil bioactivity and weed infestation in spring oilseed rape agrocoenosis of different density Aušra Grybaitė Field experiments were carried out in 2004 and 2005 at the Experimental Station of Lithuanian University of Agriculture to study the influence of different spring oilseed rape (Brassica napus L.) ‘Sponsor’ densities (50.1-100, 100.1-150, 150.1-200, 200.1-250, 250.1-300, 300.1-350, 350.1-400, 400.1-450 plants m-2) on soil bioactivity and weed infestation. Soil - Calc(ar)i-Endohypogleyic Luvisol. By increasing of spring oilseed rape crop urease activity in the soil didn’t chage significantly. The saccharase activity in the rape agrocoenosis with density more than 150.1 plants m-2 significantly increased in comparison with saccharase activity in the thinest rape agrocoenosis. The content of humus (r = 0.73, P < 0.05) and available phosphorus (r = 0.71, P < 0.05) influenced the saccharase activity. Spring oilseed rape crop density had no influence on number of weed species, weed sprouts and weed density before harvest. Efficiency of weed suppressing increased when weed density in crop at 3-4 leaves stage increased. This proved the small similarity indexes of weed density in crop at 3-4 leaves stage and before harvest. Rape crop density had no influence on weed species change. Significant negative relationship was found between weed air-dry biomass and rape crop density (r = -0.82, P < 0.01). Most of weeds in rape crop were therophytes. Most of them germinate in summer or any month (indifferent species), spread by water (barochory). Weed density at rape 3-4 leaves stage was bigger than before harvest. Qualitative distribution of weeds into biological, ecophysiological groups and types of dispersal at rape 3-4 leaves stage and before harvest was even. Quantitative distribution in 2004 was even, in 2005 uneven, because at rape 3-4 leaves stage indifferent species dominated. The work is written in Lithuanian, it consists of 45 pages, 10 tables, 14 figures, annexes and 48 references are used in the work. Key words: Brassica napus L., crop density, urease, saccharase, weed.Žemės ūkio akademijaVytauto Didžiojo universiteta

The effect of organic mulches on soil properties, segetal flora and crop productivity

Tyrimų tikslas – nustatyti organinių mulčių ir jų skirtingo storio sluoksnio poveikį dirvožemio savybėms, segetinei florai ir augalų derlingumui. Ginamieji disertacijos teiginiai: 1. Organiniai mulčiai mažina dirvožemio temperatūrą apsaugo dirvožemį nuo staigių temperatūrinių pokyčių, palaiko didesnį dirvožemio drėgnumą, mažina šlyties pasipriešinimą. 2. Organiniai mulčiai gerina dirvožemio agrochemines savybes. 3. Organinai mulčiai nevienodai veikia dirvožemio biologines savybes. 4. Mulčiavimas organinais mulčiais mažina agrocenozių piktžolėtumą. 5. Organiniai mulčiai nevienodai įtakoja žemės ūkio augalų derlingumą. 6. Žolės mulčio įtaka įvairių augalų pasėliams pagal integruoto vertinimo rodiklius yra didesnė negu šiaudų, durpių, bei pjuvenų.The experimental objective. The study was designed to establish the impact of organic mulches and different mulch layer thickness on segetal flora and crop productivity. Statements to be defended: 1. Organic mulches reduce soil temperature, protect the soil from sharp temperature changes, maintain higher soil moisture content, and reduce shear strength. 2. Organic mulches improve soil agrochemical properties. 3. Organic mulches exert different effects on soil biological properties. 4. Organic mulching reduces weed incidence in crops. 5. Organic mulches have different effects on agricultural crops productivity. 6. According to integrated assessment parameters, the effect of grass mulch on various crop stands was greater than that of straw, peat and sawdust.Žemės ūkio akademijaVytauto Didžiojo universiteta

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Vytauto Didžiojo universitetasŽemės ūkio akademij