Effects of tillage and fertilization on some selected physical properties of soil (0-30 cm depth) and on the root growth dynamic of winter barley (Hordeum vulgate cv. Niki)

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 effects of farming practices on earthworm dynamics in olive groves of central Greece (Oligochaeta)

We compared species richness, species composition, density and biomass of earthworm communities in organically and conventionally managed olive groves in central Greece. Earthworm biomass and density was significantly higher (p<0.05) in organic olive groves than in conventional olive groves. The highest species richness was recorded in the organic olive groves. Six species were recorded in total: Octodrilus complanatus, O. croaticus, Dendrobaena byblica, D. veneta, Aporrectodea caliginosa, and Microscolex phosphoreus. Only four of these were found in conventional olive groves, where D. veneta and M phosphoreus were absent. The most abundant species were O. complanatus, D. veneta, and D. byblica

Species Richness and Density of Earthworms in Relation to Soil Factors in Olive Orchard Production Systems in Central Greece

Earthworms can be used as bioindicators of soil management as they are easy to classify and very sensitive to changes of both physical and chemical soil parameters. The aim of this work was to study relations between earthworm species (richness and density) and the physicochemical soil properties such as pH, organic matter, soil moisture, and texture (percentages of sand, silt, and clay) under different farming practices (organic and conventional) in olive groves in central Greece. The data revealed significantly greater values of earthworm species richness, density, soil organic matter, and moisture in the organic olive groves than in the conventional ones. Furthermore, total earthworm density was positively correlated to earthworm Shannon diversity index, soil moisture, organic matter, nitrogen, phosphorus, and potassium in organic olive groves. However, total earthworm density was negatively correlated to soil pH and silt in conventional olive groves. It can be concluded that species richness and density of earthworms in olive groves can be considered as sensitive indicators of management practices

The effects of farming practices on earthworm dynamics in olive groves of central Greece

We compared species richness, species composition, density and biomass of earthworm communities in organically and conventionally managed olive groves in central Greece. Earthworm biomass and density was significantly higher (p<0.05) in organic olive groves than in conventional olive groves. The highest species richness was recorded in the organic olive groves. Six species were recorded in total: Octodrilus complanatus, O. croaticus, Dendrobaena byblica, D. veneta, Aporrectodea caliginosa, and Microscolex phosphoreus. Only four of these were found in conventional olive groves, where D. veneta and M. phosphoreus were absent. The most abundant species were O. complanatus, D. veneta, and D. byblica. © Kasparek Verlag, Heidelberg

Effects of aluminum and moisture levels on aluminum bioaccumulation and protein content in the earthworm Octodrilus complanatus

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

HEAVY METALS IN VINEYARDS AND ORCHARD SOILS

The application of foliar fungicides in vineyards and orchards can increase soil concentration of heavy metals such as copper (Cu) and zinc (Zn), up to the toxicity threshold for fruit trees and cover crops. However, some agronomic practices, such as liming, addition of organic fertilizers, cultivation of soil cover crops and inoculation of young plants with arbuscular mycorrhizal fungi can decrease the availability and the potential of heavy metal toxicity to fruit trees. This review aims to compile and present information about the effects of increasing concentrations of heavy metals, especially Cu and Zn, on soils cultivated with fruit trees and provides some agronomic practices of remediation. Information about the sources of heavy metals found in soils cultivated with fruit trees are presented; mechanisms of absorption, transport, accumulation and potential toxicity to plants are described