Maize represents in Slovenia for many years the most widespread field crop. For the last 10 years it has been grown on average, on 40 % of arable land, which ranks us first in Europe. The maize production is also known for its impacts on the environment. Above all, weeds are those that represent the greatest threat to maize production both in terms of economics as well as environmental impacts. This paper presents the technology of maize production in the past and its impacts on the environment, particularly groundwater. Additionally the approach of integrated plant protection, which has been developing from the concept of weed eradication to the weed management within integrated crop production, is described.
B.04 Guest lecture
COBISS.SI-ID: 4640104Majority of the intensive agricultural production in Slovenia is concentrated on the fertile arable land in the lowlands. However, the sources for most of the Slovenian drinking water are groundwater aquifers recharged through intensively cultivated shallow alluvial soils. Conservation tillage management practices where main crops are planted in the plant residues exhibited positive environmental implications not just in protecting soils from erosion, but also from preventing of leaching agrochemicals into groundwater. In the period from 2012 to 2014 series of field experiments in maize production was conducted at Agricultural institute of Slovenia in Jablje, where conventional and strip- till management systems were compared. Experimental plots were established in the field, where previous year cover crops, radish (Raphanus sativus L.), crimson clover (Trifolium incarnatum L.) and ryegrass (Lolium multiflorum Lam.) where planted in the wheat stubble. In conventional plots, cover crops where incorporated in the spring with moldboard plough, followed by spring tine cultivator seed bed preparation and maize planting. In the strip-till system, cover crops were terminated with glyphosate one week before planting and mulched if needed after which maize was planted in the cultivated strips. Early post emergence herbicide treatment was applied in both production systems. Our preliminary three years experimental results indicate, that similar germination and early growth rate of maize was determined in strip-till management systems, compared to conventional maize production system. Strip-till production system displayed alternative technology and potential for achieving high maize yields.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 4638056In years 2010-2013 series of field trials were conducted at the Agricultural institut of Slovenia experimental farm in Jablje. To study effect of cover crops on weed management, following cover crops were planted in the wheat stubbles: buckwheat, sunflower, oats, ryegrass, niger seed, camelina, radish, rape, crimson clover and lacy phacelia. All tested cover crops significantly reduced weed density and coverage in the fall and in the early spring of the following year. After termination of cover crops, plant residues were incorporated with ploughing after which, spring wheat, spring barley and maize were planted as main crops. After tillage, cover crops suppressive effect on weed infestation was still observed in main crops spring wheat, spring barley and maize, however it was strongly reduced compared to fall and early spring sampling period. Cover crops yields differ significantly between years. The greatest fresh and dry matter mass was determined in nigerseed, radish, oats and sunflower. Based on our results, cover crops strongly reduced weed infestation in the growing season and in the following spring, while after tillage considerably lower supressive effect was observed. Similarly, from 2012-2013 field experiments were conducted, where conventional, mechanical and strip till maize production systems were compared. In conventional plots standard technology with ploughing, seed bed preparation and post emergence herbicide was applied, whereas only mechanical weed control measures were tested in the mechanical weed control plots. In the strip till system maize was planted in the dead mulch of cover crops, radish (Raphanus sativus L.), crimson clover (Trifolium incarnatum L.) and ryegrass (Lolium multiflorum Lam.). Weed control was the most effective in conventional system, whereas higher weed infestation was observed in mecahnical weed control treatments. Ragardeless of higher weed infestation, yields were mainly decreased due to reduced maize plant stand. Our preliminary results indicate that similar dry maize grain yields of 9.1, 8.9 and 7.7 tons per hectar were obtained in conventional, mechanical and strip-till systems, respectively. Based on our initial results, mechanical and strip-till maize production systems represent alternative technology with comparable maize yields.
F.09 Development of a new technological process or technology
COBISS.SI-ID: 4473192Beside beneficial environmental effect in aspect of nutrients, soil and water preservation, cover crops can serve as a potential tool in the integrated weed and pest management systems. With their fast, vigourous growth and establishment, cover crops impose strong competition to weed species for nutrients, water and light. From 2010-2012 buckwheat, sunflower, oats, ryegrass, niger seed, camelina, radish, rape, crimson clover and lacy phacelia were planted in the wheat stubbles as cover crops in the experiment conducted at Agricultural Institute of Slovenia. Plant residues were incorporated in the spring of the following year, after which spring wheat, barley and maize were planted as main crops. In the growing season several assessments of weed species coverage and biomass was performed. Cover crops significantly reduced weed coverage in the fall sampling period. Similarly, in the spring of 2011 and 2012, before incorporation of cover crops residues, weed coverage in all experimental plots was significantly reduced compared to control treatment with exception of sunflower and crimson clover. However, later in the season, no effect of cover crops on weed infestation in main crops spring wheat, spring barley and maize was determined as suppresive effect diminshed and weed coverage and biomass were similar in all experimental plots. In the 2012 the greatest yields were determined in nigerseed, radish and sunflower with 28.7, 31.8 and 36.5 t of fresh and 4.3, 4.8 and 5.5 t of dry matter per hectar respectively. Based on our results, cover crops strongly reduce weed infestation in the growing season and the following spring, while further reaserch will be needed to investigate it's long term effect on weed control.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 4311912