Copper (Cu) is naturally present in all soils with a normal range of 2 -60 mg kg 21 . The traditional use of Cu fungicides against mildew diseases has led to the accumulation of Cu in some vineyard and orchard soils. Consequently, there is a move to reduce the use of these compounds in agriculture, especially in organic cultivation. A comprehensive study has not been made of the Cu content of Greek agricultural soils, which are typically alkaline with high clay content and may, therefore, be vulnerable to Cu accumulation. Within the framework of various projects, surface soil samples were taken from 10 different regions of Greece for various representative crops, and especially, for fallow soil and abandoned land. The samples were analyzed for total (aqua regia digestion) and DTPA-extractable Cu content and for several physical and chemical properties. Mean values of total Cu for the different regions of the country ranged from 16 (Limnos and Thera) to 89 mg kg 21 (Nemea), with an overall mean of 38 + 26 mg kg 21 . Significantly lower Cu content (27 mg kg 21 ) was found for annual than for other crops. The mean values for fallow land, vines, and olives were close to the overall mean, but for citrus the mean value was slightly higher. The highest value of 70 mg kg 21 was found for orchards/nuts

The root mass of winter barley (Hordeum vulgare cv. Niki) at growth stages 5, 9 and 16 of the Feekes scale increased from 100 % (0.272 mg cm–3 soil) to 132 % and 139 %, respectively. Root mass was always greater in no‐tillage (NT) plots than in ploughed‐tillage (CT) plots and was also greater where manure was applied in comparison to plots without manure. The root density at growth stages 5, 9 and 16 over all treatments was 0.197, 0.224 and 0.238 cm cm–3 soil, respectively. At growth stage 5, the root density in NT plots was 9 % greater than that in CT plots, and in rotary hoed (MT) plots it was 3 % greater. At this same growth stage, soil fertilization with NP, farmyard manure (30 t ha−1) and NP plus farmyard manure improved the root density of barley by up to 5, 10 and 11 %, respectively, in comparison with control plots. The diameter of barley roots was clearly biggest in CT plots, while in NT plots the thinnest roots were found. The mean diameter was 0.63, 0.75 and 0.78 mm at growth stages 5, 9 and 16, respectively (over all treatments). Significant correlation coefficients were found between root density (RD) and the soil properties bulk density (BD), porosity (P), penetration resistance (PR) and mean weight diameter of aggregates (MWD). For example, the highest r values were as follows: at growth stage 5, r=0.95 (P < 0.001) for P and r=0.86 (P < 0.001) for MWD; at growth stage 9, r=−0.97 (P < 0.001) for PR and r=0.96 (P < 0.001) for P, and finally at growth stage 16, r=0.97 (P < 0.001) for P and r=−0.97 (P < 0.001) for PR.

The effect of addition of organic materials (shredded pruning residues, composted olive mill by-products) on spatial distribution of soil chemical and microbial properties in irrigated and rainfed olive groves was investigated. Most of the soil parcels were subjected to reduced tillage or no tillage practices. Soil sampling took place in 40 olive groves in the region of Messinia, south-western Peloponnese, Greece during a 5-year period (2012–2017). The results showed significant increases in soil organic matter, humic acids and nitrate content at the end of the study period, compared to the first year of the soil sampling campaign. On the other hand, the relatively low amount of fresh organic materials that was applied to the soil produced unfavorable results. Differences between irrigated and rainfed soil parcels were not significant, for most of the soil properties, since the area receives much higher loads of rain than the average rainfall, as registered in the main olive growing regions of Greece. The area underneath the tree canopy favors an environment that enhances soil fertility, compared to the area out of the tree canopy. Changes of soil properties according to depth showed that the surface soil in olive orchards has the potential to sequester carbon and nutrients.

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Laboratory experiments were conducted to determine the effects of soil aluminum levels and moisture content on aluminum (Al) bioaccumulation and protein content in the earthworm (Octodrilus complanatus). The experimental design was a completely randomized block with 2 factors (aluminum content [C-0: 0 mg kg -1 , C-1: 1000 mg kg -1 , C-2: 2000 mg kg -1 , C-3: 3000 mg kg -1 ] and moisture level [M1: 100% of soil water capacity, M2: 60% of soil water capacity] and 3 replications. The lowest pH was noted in the C-0 treatment. There were no significant differences in the electrical conductivity, cation exchange capacity or total nitrogen in soil between the aluminum treatments. Moreover, there were no significant differences in soil properties between the moisture treatments. The highest soil Al content was noted in the C-3 treatment. No earthworm mortality was observed in soil contaminated with Al. Moreover, the highest aluminum content in earthworms was observed in the C-3 treatment. The aluminum content in the earthworms was significantly positively correlated with the aluminum content in the soil (r=0.984***, p<0.001). Our results indicated that the growth of earthworms was affected by the Al level. Lastly, Al caused a reduction in earthworm protein content.