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Abstract: Način pridelave navadne pire (Triticum aestivum (L.) Thell. subsp. spelta (Thell.) M.K.), še posebej gnojenje v ekološki pridelavi, zaradi pomanjkanja raziskav predstavlja dokaj nepojasnjeno področje za stroko, zato je namen tega dela pojasniti vpliv organskih gnojil in s tem dodanega dušika na rast, razvoj in tvorbo pridelka. Za namen raziskave je bil v letih 2010/2011 na njivah Univerzitetnega kmetijskega centra Pohorski dvor zasnovan poskus s štirimi gnojili (bučne pogače, Biosol, digestat in gnojevka) ter kontrolna parcela, ki ni bila pognojena v štirih ponovitvah v naključnem bloku. Proučevan je bil vpliv različnih organskih gnojil, dovoljenih v ekološki pridelavi, na nekatere morfološke lastnosti rastlin in klasa ter količino in kakovost pridelka navadne pire. Proučevani obravnavanji ne vplivata na število stebel, število klasov na m-2 in višino rastlin ter na parametre, vrednotene pri analizi klasa (dolžina klasa, število klaskov in število zrn na klas-1). Statistično značilen vpliv ima le odmerek dušika na maso zrn. Vrsta gnojila vpliva na odstotek vlage v zrnju, odmerek dušika pa na količino pridelka. V primeru gnojenja z bučnimi pogačami pridelek ni višji, je pa v tem primeru dodani dušik rastlina bolj učinkovito izkoristila – visoke vrednosti agronomske učinkovitosti (27,13 kg/m-2 plevencev kg N-1), v tleh pa je ostalo tudi manj mineralnega dušika (41,7 kg Nmin ha-1).
Keywords: pira, dušik, organska gnojila, ekološka pridelava
Published in DKUM: 14.11.2011; Views: 4214; Downloads: 282
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Abstract: Sladkorni sirek (Sorghum sacharattum L.) je energijska rastlina, pomembna v humani in živalski prehrani. Z namenom preverjanja vpliva gostote posevka (10, 15 in 20 rastlin m-2), posejanih v medvrstnih razmikih 0,45 in 0,70 m, na pridelek sladkornega sirka, maso listov, maso socvetja in morfološke lasnosti (premer stebla, dolžino stebla in celotne rastline) je bil v letu 2006 v UKC Maribor zasnovan poljski poskus v štirih ponovitvah in šestih obravnavanjih. Gostota rastlin je statistično značilno vplivala na dolžino celotne rastline, na premer stebla in dolžino stebla pa ni imela vpliva. Medvrstni razmik ni imel statistično značilnega vpliva na maso stebla, maso listov, maso socvetja in na maso celotne rastline. Ob tem pa je gostota statistično značilno vplivala na maso listov in maso celotne rastline. Najvišjo maso listov smo dobili pri 20 rastlinah m-2. Najvišji pridelek zrnja in silaže je bil dosežen pri gostoti 20 rastlin m-2. Vsebnost suhe snovi v sladkornem sirku glede na razmik in gostoto je variirala med 22,0 in 36,1 % in vsebnost sladkorjev v povprečju variira med 5,5 % v 6. listu in 14,0 % v 6. kolencu.
Keywords: sirek, rast, pridelek, sladkorji
Published in DKUM: 31.05.2011; Views: 3020; Downloads: 193
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Abstract: Biodynamic (BD) agriculture became the subject of research efforts during the last decades, whereas a part of the scientific community looks at the BD method with skepticism and marks it as dogmatic. Summarized data of published research studies showed that further research is needed in the field of food quality comparison/determination, food safety and the environmental performance (e.g. foot prints). In this sense, yields, agronomic efficiency (AE) in relation to yields in some crops and the earthworm populations depending on those crops remain to be explored under the BD production system (PS). Therefore wheat, cabbage and oil pumpkins (rotation 1) and spelt, red beet and false flax (rotation 2) were produced in three successive years (2008-2010) under 4 PS (conventional (CON), integrated (INT), organic (ORG) and BD) + control plots in a field trial near Maribor, Slovenia. Earthworms were determined in rotation 1 in October 2009 and 2010 using the „hot“mustard-extraction method. Yields in the BD PS amounted to 99, 113 and 124 percent of the average yields of all PS for wheat, cabbage and oil pumpkin seeds, respectively. Also AE of N, Nmin, P and K of the BD system for the production of all crops studied in rotation 1 was in the upper half of all PS under investigation. Moreover, earthworm populations and biomass were highest and on a similar level in the BD and ORG systems in all three crops investigated, where most were found in oil pumpkins. In the second step the ecological footprint of PS under study was calculated for wheat and spelt production and interpreted using the SPIonExcel tool. Three-year results show a markedly lower ecological footprint of the ORG and BD systems in production of both crops, mainly due to non-use of external production factors. When yields are added to the equation, the ORG and BD systems also have a lower overall footprint per product unit and ecological efficiency of production. Thus, ORG and BD systems present viable alternatives in facing environmental degradation and climate change in cereal production. However, room for improvement exists in the area of machinery use in all systems studied and yield improvement in the ORG farming system. Moreover, the importance of food quality has increased, but there remains a lack of research in this field, including sensory quality. Thus, in the third step, yields and sensory properties of white cabbage and red beet were examined in 2008 and 2009. Yields did not differ significantly among PS. A total of 167 consumers scored four attributes (color, odor, taste, and willingness to buy) using a nine-point hedonic scale. Results show significant differences between PS for both crops, where INT and control cabbage was preferred over CON cabbage samples (BD and ORG in-between), whereas BD and control red beet was preferred over CON and INT samples (ORG in-between). Lastly, the contents of sugars, organic acids, total phenolic content and the antioxidant activity were quantified in the flesh of red beet samples from 2009 using established methods. Significant differences were measured for malic acid, total phenolic content (TPC) and total antioxidant activity, where malic acid content ranged from 2.39 g kg-1 FW (control) to 1.63 g kg-1 FW (CON, ORG and INT). Highest TPC was measured in BD and control samples (0.677 and 0.672 mg GAE g-1, respectively), lowest in CON samples (0.511 mg GAE g-1). Antioxidant activity was positively correlated with TPC (r2=0.6187) and ranged from 0.823 µM TE g-1 FW to 1.270 µM TE g-1 FW in CON and BD samples, respectively, whereas total sugar content ranged from 21.03 g kg-1 FW (CON) to 31.58 g kg-1 FW (BD). The importance of the measured constituents for human health, as well as for plant resilience and health is discussed and put into perspective. Thus, the BD PS presents a viable alternative to the nowadays predominant CON and INT PS for the production of the studied crops under the Slovene subcontinental temperate climate.
Keywords: biodynamic farming, agronomic efficiency, earthworms, ecological footprint, sensory quality, chemical composition
Published in DKUM: 31.03.2011; Views: 5770; Downloads: 615
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Abstract: Toplota, svetloba, vlaga in tip tal so ključni dejavniki za kalitev in vznik rastlinic. Z namenom, da bi preverili vpliv teh dejavnikov na kalitev oljnih buč v primerjavi z jedilnimi, sta bila postavljena dva eksperimenta v rastni komori in eden v rastlinjaku. Proučen je vpliv toplotnega režima (12, 14, 16 °C), svetlobe (temno 0 ur, pol svetlo 12 ur ter svetlo 24 ur), vlage (40 % PK in 100 % PK) in tal (glinena ilovica in peščena ilovica) oz. substrat na odstotek živokalečih semen in maso rastlinic. Rezultati kažejo, da bučevkam odgovarjajo topla tla (vsaj 18 °C), kalitev v temi in 100 % PK. Zaradi omejene kalitve pri nižjih temperaturah je obvezno sejati več semen na setveno mesto in kasneje redčiti, substratu pa dodati glinene delce. Pri zasnovi je potrebno upoštevati tudi specifične zahteve vrste semena.
Keywords: oljna buča, kalitev, vznik, klimatski dejavniki
Published in DKUM: 15.10.2010; Views: 5530; Downloads: 338
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Abstract: Posamezni agrotehnični ukrepi so ključnega pomena za ekološko pridelavo. V letih 2004 in 2005 smo na Pohorskem dvoru pri Mariboru in Ptuju izvedli ekološki poljski poskus z oljnimi bučami. Namen raziskave je bil proučiti vplive leta, lokacije, zasnove posevka (seme, sadika), gnojenja s hlevskim gnojem in prekrivnih rastlin (Trifolium incarnatum L. in Trifolium alexandrinum L.), na količino mineralnega dušika v tleh, razvoj in pridelek oljnih buč. Z vključenimi obravnavanji smo želeli zagotoviti dovolj mineralnega dušika v tleh v tistih razvojnih fazah oljnih buč, ki so pomembne za oblikovanje in kakovost pridelka bučnic. Setvene pasove, smo na parcelah s prekrivnimi rastlinami, preorali tri tedne pred sajenjem buč. Razvojne faze buč smo spremljali 20, 40, 90 in 115 dni po zasnovi posevka. Mineralni dušik smo vzorčili do 0,6 m, v fazah BBCH 001, 500 in 909. Ugotovili smo, da so leto, lokacija, prekrivne rastline in gnojenje statistično značilno vplivali na morfološke lastnosti oljnih buč v razvojni fazi BBCH 700 ter pridelek v fazi BBCH 909. Zasnova posevka s sadiko je značilno vplivala na višji pridelek bučnic. Na količino Nmin v tleh so v maju vplivala vsa vključena obravnavanja, v juniju pa samo leto in lokacija. Rezultati raziskave so pokazali, da lahko prekrivni posevki in hlevski gnoj ob primerni razporeditvi padavin v rastni dobi, zagotavljajo primerno oskrbo oljnih buč z mineralnim dušikom.
Keywords: oljne buče, prekrivne rastline, mineralni dušik, hlevski gnoj, ekološko kmetovanje
Published in DKUM: 09.04.2010; Views: 5455; Downloads: 638
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