For direct sowing in soil covered with plant residues, the problem is the proper functioning of seed drills and seed drill elements, which in the case of large quantities of plant material begins to accumulate before soil openers of seeding elements and packed, this will influence on quality of direct sowing. For a survey of energy consumption and cutting quality of crop residues after harvest, we used a newly developed machine for cutting crop residues, which is by design a hybrid between disk harrow and land rollers for soil compaction. In exploitation conditions (stubble after harvest of grain maize) has been established energy consumption and quality of processing crop residues after corn harvesting.
COBISS.SI-ID: 3515752
The study was conducted at three locations in the Savinjska region of Slovenia, where soil is contaminated with heavy metals due to the zinc industry (Cinkarna Celje). In Ponikva the soil to a depth of 30 cm contains 0.8 mg kg-1 Cd, 32.2 mg kg-1 Pb and 86 mg Zn kg-1, in Medlog 1.4 mg kg-1 Cd, 37.4 mg kg-1 Pb and 115 mg kg-1 Zn and in Skofja vas 10.9 mg kg-1 Cd, 239.7 mgkg-1 Pb and 1356 mg kg-1 Zn. The pH at the selected sites was between 7.3 and 7.6. In the beginning of September 2006 two hybrids of Brassica napus L. var. napus, PR45 D01 and PR46 W31 suitable for production of biodiesel obtained from Pioneer Seeds Holding GmbH, were sown. After 96 days juvenile and after 277 days mature plants were collected. Parts of plants (root, shoot and seed) were separated and Cd, Pb, Zn, Mo and S determined by ultra-trace ICP-MS. We compared the uptake of Cd, Pb, Zn, Mo and S in different parts of juvenile and mature plants of the two different hybrids, TF (translocation factor), BAF (bioaccumulation factor) and PP (phytoextraction potential) were calculated. The mature hybrid PR46 W31 had higher shootžroot ratio and higher PP for metals (Cd, Pb and Zn) and lower PP for the micronutrient (Mo) and macronutrient (S) on the polluted site. The study demonstrated the potential use of oilseed rape on multiply polluted soils for production of 1st and 2nd generation biofuels. The potential restoration of degraded land could also disburden the use of agricultural land.
COBISS.SI-ID: 1116886
Millions of hectares of agricultural land are contaminated world-wide. Soil degradation processes, now already enhanced by the effects of climate change, will increase the tendency to use contaminated land for food production, thus increasing the human health risk. Remediation technologies have the potential to preserve now contaminated soil for the safe production of food. However, before these emerging technologies are applied in full-scale, the effect of remediation on the long-term quality and safety of soils and on crops and vegetables grown on remediated soil needs to be carefully examined. Currently there is almost no data on these effects in scientific literature. Soil washing with chelants such is EDTA is an effective and potentially soil-friendly remediation option for toxic metal contaminated soils. However, soil washing cannot remove toxic metals from soil entirely, even at high chelant-to-metal ratios, and the long-term risks associated with residual metals are still largely unknown. Novel EDTA-based soil washing technology, using acidic EDTA precipitation and electrochemical recovery of toxic metals and metaloides from spent soil washing solution will be presented. Method enables EDTA recycling and reuse of process water in a closed process loop and was evaluated for technical and economic feasibility in a pilot-scale study using 60-75 kg soil batches. Soil washing of Pb (1950 mg kg-1), Zn (800 mg kg-1), Cd (10 mg kg-1) and As (120 mg kg-1) contaminated garden soil from Meza Valley, Slovenia, using 60 mmol kg-1 EDTA removed 80, 40, 70 and 80% of toxic metals, respectively. After remediation potential pytoavailability (DTPA extraction) of soil residual metals was reduced for 80, 80, 65 and 65%, mobility (TCLP) for 30, 20, 40 and 35%, oral bioavailability from stomach phase (PBET) for 40, 65, 75 and 90% and from intestinal phase for 55, 45, 55 and 40% for Pb, Zn, Cd and As, respectively. The effect of remediation on soil chemical properties: toxic metal fractionation, pH, organic matter and carbonate content, C:N ratio, P and micro-nutrient concentration, cation-exchange capacity; on soil physical properties: soil structure, water potential and water holding capacity; and on soil biological properties: microbial diversity (bacterial and fungal genomic DNA), induced respiration, dehydrogenase, glukosidase, phosphatise (acid, alkaline), urease and esterase (FDA) activity was studied and will be presented. The functioning of remediated soil as a plant substrate was evaluated in the experimental garden and compared against non-remediated soil. Leachability of Pb, Zn, Cd and As was monitored using lysimeters. The growth of Chinese cabbage (Brassica pekinensis), onion (Allium cepa), cauliflower (Brassica oleracea), green pea (Pisum sativum), spinach (Spinacia oleracea) and toxic metals uptake into the plants green parts and roots were measured. Colonization of plant roots with arbuscular mycorrhizal fungi, leaf gas-exchange and chlorophyll fluorescence were estimated.
COBISS.SI-ID: 6816377