Olive Grove Soils Research Articles

Cumulative and Residual Effects of Two-Phase Olive Mill Waste on Olive Grove Production and Soil Properties

Modern olive (Olea europaea L.) mill extraction techniques generate a large amount of two-phase olive mill waste (OMW) containing up to 90% organic matter. Recycling OMW as a soil amendment may represent a solution for its disposal, especially in Mediterranean areas, where many soils are characterized by very low organic matter levels. A 10-yr field study was conducted to evaluate the long-term sustainability of raw OMW disposal as a soil amendment on an olive grove in Elvas, Portugal. The soil was amended with OMW at rates of 0, 30, and 60 Mg ha ―1 , dry weight equivalent, for 8 yr, with cumulative and residual effects being assessed in the last year and 2 yr after the last application. Long-term applications of OMW to soil led to cumulative and residual effects on soil physical [aggregate stability and bulk density (D b )], chemical [total organic carbon (TOC) and its humified fractions, total N, available P, and K], and biochemical [dehydrogenase (DH), urease (UR), 3-glucosidase (GLU), alkaline phosphatase (PHO), and arylsulfatase (ARS) activities] properties, and contributed to an increase in olive yields compared with the control (>17%, > 1.47 Mg ha ―1 ). However, electrical conductivity (EC) rose significantly with OMW application, especially in the residual year, ranging from 0.513 dS m ―1 for the unamended soil to 2.29 dS m ―1 at the 60 Mg ha ―1 application rate. Repeated addition of OMW to olive grove soils may be a useful strategy for recycling this organic amendment to improve soil fertility and increase yields. However, long-term use of OMW increases the risk of soil salinity, especially if application rates are >30 Mg ha ―1 .

Influence of two-phase olive mill waste application to soil on terbuthylazine behaviour and persistence under controlled and field conditions

Purpose Terbuthylazine is one of the most common herbicides used to control weeds in olive groves. Application of two-phase olive mill waste (OW) to soils may play a fundamental role in the management of leaching losses of pesticides, especially in Mediterranean areas where soils are characterized by low organic matter levels. We evaluated the impact of OW amendments on the sorption–desorption, degradation, leaching, and persistence of the herbicide terbuthylazine in a representative olive grove soil from Portugal.

Effects of oil mill wastes on surface soil properties, runoff and soil losses in traditional olive groves in southern Spain

In Spain, agriculture triggers soil degradation and erosion processes. New strategies have to be developed to reduce soil losses and recover or maintain soil functionality in order to achieve a sustainable agriculture. This experiment was designed to evaluate the effect of two olive mill wastes (olive leaves and “alperujo”) on soil properties and soil erosion in a rain fed olive grove in SE Spain. After three years experiment, oil mill wastes application significantly improved physical and chemical properties of the studied soil with respect to control. The organic matter content, bulk density and porosity were increased, which confirmed the interactions of these properties. Available water capacity increased with olive leaves but decreased when applied “alperujo”. With respect to erosion, after simulated rainfall experiments it was found that the oil mill wastes contributed to increase the roughness and the interception of raindrops, delaying runoff generation and enhancing the infiltration of rainwater. Treatment with oil mill wastes contributed to a reduction in runoff generation and soil losses compared to bare soil, especially when applied olive leaves. ► We added olive mill wastes (olive leaves, “alperujo”) on rain fed olive grove soil. ► We compared the effect of olive leaves and “alperujo” on soil properties and soil erosion. ► Oil mill wastes application significantly improved physical and chemical properties. ► Oil mill wastes contributed to a reduction in runoff generation and soil losses. ► Olive leaves are recommended: they reduce erosion and increasing the water available.

De-Oiled Two-Phase Olive Mill Waste Application Impact on Phosphorus Sorption and Fractionation in a Mediterranean Soil Under Olive Production

Low phosphorus (P) availability is a critical impediment to agricultural use of P-fixing soils. De-oiled two-phase olive mill waste (DTOMW) may be used as a soil amendment that can increase P availability and consequently improve crop production. The aim of this study was to investigate the effect of DTOMW amendments to soil on the fractionation, sorption, and buffering capacity of P in soils collected from a typical olive grove amended in the field with 27 and 54 Mg ha−1 of DTOMW for 7 years. Cumulative and residual effects were evaluated in the last year of DTOMW application and 2 years subsequent to the last application. A modified Hedley fractionation scheme was used to evaluate the change in soil P forms, whereas the potential for sorption of P was evaluated by applying the surface Langmuir models to sorption isotherms. The P fractionation results indicated an increase in all P fractions (P < 0.05) in the studied samples. The order of the rates of increase in concentrations of P fractions was HCl-Pi > NaHCO3-Pi ≈ NaOH-Po > HCl-Po ≈ NaOH-Pi > H2O-Pi > NaHCO3-Po > residual P > H2O-Po in the cumulative year, whereas in the residual year, the order of increase was HCl-Pi > NaOH-Po > NaHCO3-Pi > H2O-Pi > NaOH-Pi > HCl-Po > residual P > NaHCO3-Po > H2O-Po. The DTOMW amendments significantly decreased the P sorption maxima (P < 0.05). Most of the total P sorption potential was attributed to low-energy sites, independent of the amendment applications received. The DTOMW soil application decreased indices of P-binding intensity at both high- and low-affinity sites, decreased the P equilibrium buffering capacity, and increased the equilibrium P concentration, indicating that P availability increased with increasing DTOMW rate and also with increasing humified organic matter fraction. This study has shown that in olive grove soils, successive DTOMW amendments may be an effective management practice for controlling their ability to fix inorganic P and increase P availability for the crop for at least 24 months after its application.

Direct and residual effects on diuron behaviour and persistence following two-phase olive mill waste addition to soil: Field and laboratory experiments

Two-phase olive mill waste (TPOMW) is a by-product of olive oil extraction, contains up to 90% organic matter, and may be used as a soil amendment. In order to investigate the impact of TPOMW amendments to soil on the sorption-desorption, degradation, leaching, and persistence of the herbicide diuron, field and laboratory experiments were conducted on a representative olive grove soil. The soil was amended in the laboratory with TPOMW at the rates of 5% and 10%, and in the field with 30 and 60 Mg ha − 1 of TPOMW for seven years. Direct and residual effects were evaluated in the last year and two years after the last TPOMW field application (2005 and 2007, respectively). Significant increases in diuron sorption were observed with the greater amount of TPOMW in the laboratory and field-amended soils, mainly promoted by an increase in humic acid content, this process being more reversible in the laboratory than in the field amended soils. The TPOMW soil application only significantly increased the half-life of diuron in the laboratory amended soils, ranging from 8.5 days for the original soil to 32 days at the greater application rate. The TPOMW amendments significantly reduced the downward mobility of diuron, and reduced the amount of herbicide leached in the laboratory and field-amended soils, with a major residual decrease two years after the last waste addition since no herbicide leached through these amended-soil columns. In the field persistence study, TPOMW addition increased diuron retention mainly in the upper 30 cm of the soils, decreasing the herbicide's vertical movement through the amended soils. The residence time of diuron increased with increasing TPOMW rate, especially in the direct year (2005). The results revealed major changes in diuron's behaviour due to the different TPOMW loading rates and the transformation of the amendment during two years of biodegradation in the soil. This study has shown the usefulness of TPOMW for reducing groundwater contamination by pesticides for at least 24 months following its application.

Simulation of soil organic carbon stocks in a Mediterranean olive grove under different soil-management systems using the RothC model

Agricultural soils play a very important role in regulating the carbon dioxide (CO2) content of the atmosphere, and can behave either as carbon sources or sinks. We have simulated the dynamics of carbon in the soil under different land uses and soil-management systems in a Mediterranean olive grove with the Rothamsted carbon (RothC) model. To this end we chose patches of native vegetation (NV) and two different olive grove soils (chromic calcisols and calcic vertisols) under different soil-management systems: conventional tillage (T), and mulching with shredded olive-pruning debris and residues from olive-fruit cleaning (PD + CR). We measured the clay content, bulk density, soil organic carbon (SOC) and total nitrogen (N) in each patch. The SOC and N values decreased by more than 30% as a result of a change in soil use from NV to T olive grove. After adding PD + CR these values rose once more, even to levels above NV. The RothC model performed well for covered soils (NV and PD + CR) but overestimated the SOC values after the soil use was changed from NV to T olive grove, probably due to high carbon losses caused by erosion, common to T soils in the Mediterranean basin. As a result of mulching the soil with only pruning debris, CO2 emitted to the atmosphere was reduced by >55% for both soils. Associated with this decrease in the emission rate, RothC estimated a potential carbon sequestration of 0.5 and 0.6 t C/ha/yr for chromic calcisols and calcic vertisols, respectively. The reuse of organic debris generated in the olive grove, such as pruning debris and residues from olive-fruit cleaning, is an efficient way of improving soil properties, diminishing CO2 emissions and increasing the soil’s capacity to store carbon.

Cumulative and residual effects of de-oiled two-phase olive mill waste application to soil on diuron sorption, leaching, degradation, and persistence

Laboratory and field experiments were conducted to evaluate the influence of de-oiled two-phase olive mill waste (DTPOMW) amendments on the sorption–desorption, degradation, leaching, and persistence of the herbicide diuron in a representative olive grove soil. The soil was amended in the laboratory with DTPOMW at the rates of 5% and 10% (w/w), and in the field with 27 and 54 Mg ha −1 of DTPOMW for 7 years. Cumulative and residual effects were evaluated in the last year and 2 years after the last DTPOMW field application (2005 and 2007, respectively). The results showed that the adsorption of diuron to the soil significantly increased in the presence of DTPOMW in the laboratory and field-amended soils, and that humic acid content was mainly responsible for this increase. The DTPOMW soil application only significantly increased the half-life of diuron in the laboratory-amended soils, ranging from 8.6 d for the original soil to 51 d at the greater application rate. The DTPOMW amendments significantly reduced the downward mobility of diuron, and reduced the amount of herbicide leached in the laboratory and field-amended soils, and no residues of diuron were detected in the leacheate of the residual-amended columns. In the field study, DTPOMW addition increased the persistence of diuron in the upper 10 and 5 cm of the soils in the cumulative and residual years, respectively, decreasing the herbicide’s vertical movement through the amended soils with increasing DTPOMW rate. This study has shown that in olive grove soils DTPOMW amendment may be an effective management practice for controlling ground water contamination by diuron.

Short and medium-term effects of two-phase olive mill waste application on olive grove production and soil properties under semiarid mediterranean conditions

A five-year field study was conducted to evaluate the potential use of oiled and de-oiled two-phase olive mill waste (TPOMW and DTPOMW, respectively) as soil amendment on a representative olive grove soil: a Cutanic Luvisol. Treatments included a non-amended control, TPOMW1, TPOMW2, DTPOMW1 and DTPOMW2 (30, 60, 27 and 54 Mg ha −1 dry weight equivalent). Significant increases ( P < 0.05) in organic carbon, total N, available P and K, and aggregate stability were observed in the amended soils. Leaf analysis showed significant increases in N, P, and K concentrations in treated plots after the two first years of TPOMW or DTPOMW amendments. Also, a general increase in olive production was observed in the treated plots, this increase being higher in the TPOMW1 and DTPOMW1 treated soils. After five years of repeated TPOMW and DTPOMW application, the increase in yield was 29%, 9.8%, 30%, and 19% for TPOMW1, TPOMW2, DTPOMW1, and DTPOMW2, respectively. Raw TPOMW and DTPOMW have the potential to be valuable soil amendments and source of organic matter, with a positive effect on olive yield, and closing the cycle of residues-resources.

Isolation and characterization of Bacillus thuringiensis strains from olive-related habitats in Turkey

To isolate Bacillus thuringiensis strains from different olive-related habitats (olive groves and olive oil factories) in Turkey and to characterize these strains by molecular methods. A total of 150 samples, consisting of olive grove soil, green olive leaves, olive leaf residues, animal faeces, olive pomace and dust, were examined for the presence of B. thuringiensis. One hundred B. thuringiensis strains were isolated from 54 environmental samples (36%) and characterized in terms of crystal morphology, cry and cyt gene content by polymerase chain reaction, plasmid profiles and 16S-internal transcribed spacer ribosomal DNA restriction fragment length polymorphism (16S-ITS rDNA RFLP). The highest percentage of samples containing B. thuringiensis was found in 38 out of 54 total soil samples (70%). Of the 100 B. thuringiensis isolates, the most frequent crystal shapes were irregularly shaped (24%), spherical-irregular pointed (19%), cuboidal (17%) and spherical (16%). The cry1 plus cry4 genotype was the most abundant genotype in our collection (21%). RFLP analysis of the amplified 16S-ITS rDNA revealed 11 distinct patterns for the isolates and 10 reference strains. Bacillus thuringiensis isolates showed a great genetic diversity and crystal shape heterogeneity. This is the first study on the isolation and characterization of B. thuringiensis from olive-related habitats in Turkey. No correlation was observed between the cry genotypes and insecticidal crystal shapes of the isolates. Restriction profiles of 23% of the isolates were found to be different from those of the 10 reference strains used.

Changes in organic matter and residual effect of amendment with two-phase olive-mill waste on degraded agricultural soils

Agricultural soils from many parts of the Mediterranean region are very poor in organic matter and are exposed to progressive degradation processes. Therefore, additions of the olive-mill waste from a continuous two-phase system as an organic amendment can improve soil quality and hence mitigate the negative environmental and agronomic limitations of these soils. A field study under semiarid Mediterranean conditions was conducted to evaluate the changes in organic matter after four consecutive annual additions of olive-mill watery husk (OMWH) waste and the de-oiled two-phase olive pomace (TPOP) waste on an olive grove soil: a cutanic Luvisol (CL). Treatments included a control, OMWH (30 and 60 Mg ha(-1), DW equivalent), and TPOP (27 and 54 Mg ha(-1), DW equivalent). Also, a two-year greenhouse study using wheat (Triticum aestivum L.) was conducted to evaluate the residual effects of adding OMWH to CL soil and to a degraded Leptic Cambisol (LC). Treatments included five OMWH rates ranging from 0 to 40 Mg ha(-1). Significant increases in total organic carbon (TOC), water soluble organic carbon (WSOC), humic and fulvic acids, and aggregate stability were observed in the treated plots, and the highest humification index was obtained when OMWH was applied at the lowest rate. The increase in aggregate stability correlated positively and highly significantly (P<0.01) with the humic and fulvic acid and WSOC contents. In the greenhouse, significant increases in TOC, carbohydrates, aggregate stability, total N, available K, and cation exchange capacity were observed in both soils. However, available P decreased significantly. There was an increased residual fertilization effect of OMWH for both soils. The best fits to grain yield and OMWH rates were with a linear regression for the CL soil (R(2)=0.957 and P<0.01), and a quadratic regression for the LC soil (R(2)=0.960 and P<0.01).

Abundance and diversity of soil arthropods in olive grove ecosystem (Portugal): Effect of pitfall trap type

Soil arthropod biodiversity is an indicator of soil quality and can be studied using pitfall trapping. In this research, olive grove edaphic fauna was assessed at different sampling dates by comparing two different diameters (7 and 9 cm) and three different contents (empty, water and preservative) of pitfall traps in order to determine which type of pitfall trap is more efficient. Considering all pitfall trap types and sampling times, a total of 12,937 individual edaphic arthropods belonging to 11 taxa were recovered. Smaller traps with preservative collected significantly more individuals than the other pitfalls tested. Larger and empty traps collected significantly more spiders and traps with preservative collected more beetles. Smaller and empty traps collected fewer individuals than the other trap types. Both Shannon's diversity and Pielou's evenness indexes were higher in the larger and empty traps and richness was higher in the smaller traps filled with water. The study of myrmecocenosis was emphasised because olive grove soil fauna was numerically dominated by Formicidae (56.6% of all organisms captured) belonging to 12 genera and 24 species; Tapinoma nigerrimum, Messor barbarus, Cataglyphis hispanicus, Tetramorium semilaeve, Cataglyphis ibericus, Messor bouvieri and Camponotus cruentatus were the most abundant ant species. Traps with preservative reached the highest accumulation of species for a small number of pitfalls when compared with the other pitfalls studied and a sampling effort of 20 samples is apparently sufficient to sample the greater part of the ant species of the olive grove. From this study, it seems that traps with preservative are the best choice to use in further studies concerning the epiedaphic fauna of the olive grove.

Impact of Sewage Sludge Compost Utilization on Chemical Properties of Olive Grove Soils

Field experiments were conducted for four years, between 1998 and 2002, in two olive grove soils of adult olive orchards (Olea europaea L. cv. Cornicabra) in a clay loam soil in Seseña (Toledo, Spain) and in a sandy loam soil in Aranjuez (Madrid, Spain). There were four treatments, sewage sludge compost (SSC), sewage sludge compost plus urea (SSC+U), urea (U) and control (C). Each treatment was replicated four times and two depths were studied (0-15 and 15-30 cm). Once a year, before spreading sewage sludge compost, soil samples were taken at depths of 0 to 15 cm and 15 to 30 cm. Organic matter, total Kjeldhal nitrogen, phosphorus availability, pH, and electric conductivity were measured. No differences were found between treatment on organic matter and electric conductivity after four years of application of sewage sludge compost to two olive grove soils. In relation to nitrogen content, sewage sludge compost, only in Seseña, produced higher nitrogen soil content than the traditional urea treatment. Sewage sludge compost applied on olive grove soils improved the Phosphorus availability for the olive tree. In Aranjuez, the use of sewage sludge compost increased the pH of the soil with respect to Urea and Control plots. In Seseña, the reverse effect was found.

Agrology In Olive Grove Soils In TheP.D.O. Baena (Spain)

Nowadays it is possible to observe that many zones present great imbalances in the use of soils with respect to the potential possibilities. These imbalances are very important because they produce a decrease of the crop production and a degradation of soil properties that lead to great environmental problems. In this project, a methodology of work based on the Geographic Information System (GIS) has been developed for the study of the problems these situations are generating. The development of this GIS methodology has generated a useful tool for the evaluation of the present soil use to get its optimal productive capacity. Then, and with the data collected in this evaluation, it is possible to develop a planning and exploitation model that formulates the way to adapt the