Long-term field experiment to follow various effects of conservation soil tillage is conducted at Biotechnical faculty in Ljubljana. The soil is Eutric Gleysol. Conventional treatment with plowing, 22 cm deep P, and conservation treatment by rotary harrow to a depth of 10 cm N, and subplots with compost amendment (-c) and without fertilization (-n) were observed. After 5 years nutrient contents and organic matter were higher in N than P. Compost addition had a positive effect on microbial biomass, but the tillage system did not affect it. However, nitrogen mineralization and decomposition of straw were higher in P as in N, and in the soil depth of 15 – 20 cm than in the 5 – 10 cm.
The effect of remediation using three EDTA doses (10, 30, 60 mmol kg−1) on soil functioning was assessed using column experiment and Brassica rapa. Soil washing removed up to 77, 29 and 72% of metals from soil contaminated with 1378, 578 and 8.5 mg kg−1 of Pb, Zn and Cd, respectively. Sequential extraction indicated removal from the carbonate soil fraction. Metal oral-accessibility from the stomach phase was reduced by up to 75 and from the small intestine by up to 79% (Pb). Part of metals (up to 0.8% Cd) was lost due to leaching from columns. Remediation reduced toxic metal soil-root transfer by up to 61% but did not prevent metal accumulation in leaves. The fitness of plants grown on EDTA washed soils (gas exchange, fluorescence) was not compromised. Remediation initially reduced the soil DNA content (up to 29%, 30 mmol kg−1 EDTA) and changed the structure of microbial population.