Zatiranje plevela v ekološkem kmetijstvu / Organic farming weed control

Ker je uporaba mnogih fitosanitarnih sredstev ekološkem kmetijstvu prepovedana (Uredba 889/2008, priloga II.), najdemo na trgu vedno več strojne opreme za zdravstveno varstvo poljščin. Strojni pripomočki za nego tal so okoljsko sprejemljivejši kot raba fitosanitarnih sredstev, vsaj iz vidika toksičnosti za ekosisteme in vpliva na zdravje ljudi.

[en] As many phytosanitary products are not allowed in organic farming (Regulation 889/2008, annex II.), more and more mechanical weed control equipment is sprouting out on the market. Machine weed cotrol is more environmentally acceptable than phytosanitary products, at least from the point of ecosystem toxicity and human health impact.

15. 06. 2009 sem se udeležil predstavitve delovanja priklopne mehanizacije za zatiranje plevela, ki se je zgodila v Studencu pri Krtini. Na koruznem polju smo si lahko ogledali uporabo česala in naprave za termično zatiranje plevela.

[en] Last month, I went to a public presentation of towed weed control machinery. The use of a tine weeder and a weed-heat-control device was demonstrated on a corn field.

S poljskim česalom kombiniramo zatiranje plevelov z nego tal. Z delovanjem česala prezračujejo in rahljajo zemljo ter preprečujejo zaskorjenost (posledica je izbljšana vodna kapaciteta tal in večja količina rastlinam dostopnih hranil). V predstavitvi se je poljsko česalo se je izkazalo za bolj uspešnega pri odstranjevanju širokolistnega plevela. Četudi s takim načinom zatiranja plevela z njive ne odstranimo vseh nezaželenih rastlin v končni fazi ti 'slepi potniki' sami prispevajo k večji vlažnosti tal.

[en] The tine weeder allows the combination of weed control and tillage practices. The tines aerate and crush the crust of the soil (consequentially, the field water capacity and plant nutrient availability is improved). The presented tine weeder was more successful in the removal of the broadleaved weed types. Even as all the weeds are not remowed from the field, these remaining stowaways do contribute to a higher moisture content of the ground.

priklopno česalo, plod znanja in dela s kmetije, na kateri je potekala predstavitev
[en] the presented tine weeder was farm-made

levi dve vrsti sta obdelane s česalom
[en] the weeder was used on the left two rows

O napravi za termično zatiranje plevela, ki se prodaja pod imenom ecobrena, smo slišali že veliko na lanskem 46. kmetijsko živilskem sejmu v Gornji Radgoni, kjer je ecobrena prejela bronasto medaljo. Traktorski priključek je sestavljen iz plinskih šob, razvodil, varnostnih ventilov in nosilca za plinske jeklenke. Šobe usmerjajo plamen pod takim kotom, da uniči plevele, in razkuži zogrnji del tal, posevek pa pusti nepoškodovan.

[en] I have already seen the gas wead-control tractor trailer last year at the 46. International Agricultural – Food Fair in Gornja Radgona, where the device was awarded a bronze medal for mechanical equipment. The attachment is composed of gas burning nozzles, leading hoses and a hoalder for gas cylinders. The nozzles dirrect the flames toward the weeds between the rows and away from the crop. The heat also disinfects the soils top layer.

ecobrena med delovanjem
[en] operating the ecobrena

po obdelavi je uničena cela rastlina
(fotosinteza je prekinjena tudi v zelenih delih rastline na sliki)
[en] after burning, the whole plant is destroyed
(the photosynthesis stopped in the plant green parts, too)

ročna izvedba
[en] hand-operated model

Zanimiva bi bila še primerjava emisij toplogrednih plinov na račun fitosanitarnih sredstev in zaradi rabe zemeljskega plina (poraba pri prototipu ecobrene je kar velika, 20-40 kg/ha). Vprašanje je, ali bi samo izgoravanje zemeljskega plina sploh kompenzirala toplogredna bilanca proizvodnje, transporta in nanašanja ekvivalentne funkcionalne količine fitosanitarnih sredstev.

[en] It would be interesting to work out a comparison of the greenhouse gas emissions due to the usage of common phytosanitary agents and the usage of such earth-gas based practices (the tractor model consumes 20 to 40 kg gas/ha). It is questionable wether the mere gas burning itself is compensated by the global warming potential decrease of the pesticide functional equivalent production, transport and application.