Search

Detailed knowledge of soil properties is fundamentally important for optimizing agriculture practices and management. Meanwhile, the spatial distribution of soil physicochemical properties is considered a fundamental input of any sustainable agricultural planning. In the present study, ordinary kriging, regression kriging and IDW were chosen for deciphering soil spatial variability and mapping soil properties in a reclaimed area of the Behera Governorate of Egypt where soil arose from two different types, one sandstone and the other limestone. Geostatistics were used to show the interrelationships and conditions of soil properties (available phosphorus, potassium and nitrogen, EC, pH, Sp, ESP, CEC, OC, SAR, and CaCO3). The results of mapping spatial soil variability by Geostatistics could be used for precision agriculture applications. Based on the soil test results, nutrient management recommendations should be applied regarding variable rates of fertilizers. The performance of the maps was evaluated using Mean square error (MSE). Inverse distance weight (IDW) showed higher efficiency than Kriging as a prediction method for mapping the studied soil properties in the study area. The results of the present study suggest that the application of the selected fit model worldwide in any relevant study of soil properties of different geological sources is feasible.

Land evaluation is imperative for its efficient use in agriculture. Therefore, this study aimed at assessing the suitability of a region in West El-Minia for cultivating some of the major crops using the geographical information system (GIS). The results focus on allocating space for cultivating sugar beet and utilizing the free period of sugar beet in other crops. This exploitation helps to maintain the quality of the land and increase its fertility by using crop rotation with integrated agricultural management. A machine learning technique was implemented using the random forest algorithm (RF) to predict soil suitability classes for sugar beet using geomorphology, terrain attribute and remote sensing data. Fifteen major crops were evaluated using a suitability multicriteria approach in GIS environment for crop rotation decisions. Soil parameters were determined (soil depth, pH, texture, CaCO3, drainage, ECe, and slope) to characterize the land units for soil suitability. Soils of the area were found to be Entisols, Typic Torrifluvents, Typic Torripsamments and Typic Torriorthents and Aridsols, Typic Haplocacids, Calcic Haplosalids and Sodic Haplocalcids. Overall, the studied area was classified into four suitability classes: high “S1”, moderate “S2”, marginal “S3”, and not suitable “N”. The area of each suitability class changed depending on the crop tested. The highest two crops that occupied S1 class were barley with 471.5 ha (representing 6.8% of the total study area) and alfalfa with 157.4 ha (2.3%). In addition, barley, sugar beet, and sorghum occupied the highest areas in S2 class with 6415.3 ha (92.5%), 6111.3 ha (88.11%) and 6111.3 ha (88.1%), respectively. Regarding the S3 class, three different crops (sesame, green pepper, and maize) were the most highly represented by 6151.8 ha (88.7%), 6126.3 ha (88.3%), and 6116.7 ha (88.2%), respectively. In the end, potato and beans occupied the highest areas in N class with 6916.9 ha (99.7%) and 6853.5 ha (98.8%), respectively. The results revealed that the integration of GIS and soil suitability system consists of an appropriate approach for the evaluation of suitable crop rotations for optimized land use planning and to prevent soil degradation. The study recommends using crop rotation, as it contributes to soil sustainability and the control of plant pests and diseases, where the succession of agricultural crops on a scientific basis aims at maintaining the balance of nutrients and fertilizers in the soil.

The main aim of the LIFE+ OLIVECLIMA project is to trial the introduction of new cultivation practices for tree crops in order to find a cost-effective means of mitigating and adapting to climate change, through the increase of carbon sequestration by soils, and reduction of greenhouse gases emissions. In order to determine the benefits of using cover crops on soil fertility and biodiversity, an investigation with different combinations of legumes and oat has been conducted during 2014-2015 in Chania, Greece, in a low tree density rain-fed olive orchard covered dominantly by Oxalis pes-caprae weed. The treatments were: natural vegetation, bare soil, only oats, only Vicia sativa, mixture of four legumes with oats and mixture of five legumes with oats. Seed emergence and soil cover was monitored and soil was monthly sampled at three depths (0-10, 10-20 and 20-30 cm) for analysis. During plant growth, significant fluctuations in soil NO(3)-N and NH(4)-N content were recorded. Similarly, soil CO(2) emissions increased with plant growth and air temperature raise. Sowing cover crop mixtures is a promising soil management practice to increase soil fertility and enrich plant and microbial biodiversity in olive orchards especially when dominated by Oxalis pes-caprae a very aggressive weed in many Mediterranean areas.

Water scarcity in the Mediterranean region is becoming a growing concern, threatening the viability of agriculture, which is one of the main economic sectors in many areas. The design of an optimal irrigation management plan, based on state-of-the-art measuring and modeling tools, can effectively contribute towards water saving efforts and potentially address the water scarcity issue in the region. This paper describes the development and application of an integrated decision-making system for the management of water resources of olive and citrus crops in the North of Chania, Crete, Greece. The system integrates different field measurements, for example 2088 soil moisture measurements taken within the study area, and modeling approaches to simulate flow in the unsaturated zone. After the successful calibration and validation of the model, the spatio-temporal representation of soil moisture and pore water pressure were used as guidance for developing optimal irrigation plans, taking into account the water needs of olive and citrus crops, aiming to maximize crop yield, agricultural income, and promote water saving efforts. According to the results, water use can be reduced by up to 36% during the dry season, compared to conventional irrigation practices for citrus trees. Similarly, for olive trees, the reduction in water use can reach up to 41%. The proposed methodology can also be cost-effective in terms of water value, saving about 40% from the typical water cost for irrigation in the study area. The impact of climate change on water resources availability in the area and water conservation efforts were also investigated for the period of (2019-2030). Results show that, comparing the Baseline, RCP 8.5 and RCP 4.5 climatic scenarios, the highest savings on average are observed for emission scenario RCP 4.5 with 53.3% water savings for olive trees and 46.7% for citrus trees.

Olive cultivation is considered as one of the most significant agricultural activities in Greece, from a financial, social, and ecological point of view. Intensive cultivation practices in combination with the Mediterranean climate, lead to depletion of soil organic matter, erosion, desertification, and degradation of water resources. This paper describes sustainable olive crop management practices that were comparatively applied in 120 olive groves in Greece for 5 years with the participation of three farmers groups. Organic materials recycled in the olive groves during the present study were valuable sources of carbon, nitrogen, phosphorus, and potassium. Carbon content was highest in pruning residue (53.8&ndash, 54.2%) while all materials studied were considered rich in C ranging between 41.9&ndash, 46.2% (compost) and 34.9&ndash, 42.5% (three-phase olive mill waste-OMW). The highest content in nitrogen was detected in compost (2&ndash, 2.45%) followed by pruning residue (0.93&ndash, 0.99%) and OMW (0.03&ndash, 0.1%). Compost was considered a good source of phosphorus (0.3&ndash, 0.6%) followed by pruning residue (0.08&ndash, 0.13%) and OMW (0.01&ndash, 0.3%). Potassium was also considerable in the organic materials recycled ranging 0.5&ndash, 1.5% in compost followed by pruning residue (0.5&ndash, 0.7%) and OMW (0.3&ndash, 1.1%). Adoption of modified pruning also had important contribution toward sustainable management of olive trees. Sustainable pruning resulted in a well-balanced ratio between vegetative growth and fruiting (balanced, every year, in order to eradicate biennial bearing). Significant fluctuation in olive yields was observed in the first years of the project while yields were gradually stabilised by applying sustainable crop management. In parallel, yield increase without additional inputs, lowers the carbon&mdash, environmental footprint of the product regarding several environmental impact categories. Results can be integrated in the national agricultural and environmental policy in Mediterranean countries toward the achievement of a circular economy.

Olive trees constitute one of the most dynamic cultivations for Mediterranean countries, while their economic importance is high. As water constitutes a fundamental factor affecting olive tree production, soil water content is a most critical parameter that must be monitored to improve olive trees’ cultivation management. Effects of precipitation, irrigation, and soil management on water content in four soil depths (10, 20, 30, 40 cm), four periods of the year (February–March, April–May, June–July, August–September) and three successive years were determined in 12 Mediterranean olive groves (Trifilia, southern Greece) as well as their respective fruit and olive oil yields. Significantly higher soil water content was recorded in the first (+16.8%) and third (+27.4%) year compared to the second year. Higher (+6.8%) water content was observed in irrigated olive groves compared to rainfed fields. Higher (+5.6%) water content was observed in sustainable olive groves compared to intensively managed fields. Significantly, higher soil moisture was recorded at 40 and 30 cm depth compared to 10 cm depth while intermediate values were observed at 20 cm. Marked increase in fruit yield was achieved through sustainable management (+39%) compared to intensive olive groves. The potential to improve irrigation practices in the area was also indicated by results of the present study.

The objective of this work was to classify and map the areas environmentally sensitive to desertification in the Mediterranean island of Crete. Sensitivity to desertification was estimated with a modification of the MEDALUS Environmentally Sensitive Area Index (ESAI) approach, using 15 quantitative parameters divided into four main quality indices: climate, vegetation, soils and management quality. The ESAI methodology was modified to include two additional parameters related to soil quality (water erosion and soil organic matter). According to the results, 37% of the island's area is characterized as critically sensitive to desertification. This percentage varies significantly across the island, with the western part having the least critically sensitive areas, and the eastern part the most critically sensitive. The results of this study also indicate that critically sensitive areas are found in the eastern side of the island mainly due to human-related factors and climatic conditions. It was concluded that the proposed methodology is a valuable tool for regional-scale assessment of areas environmentally sensitive to desertification in Mediterranean environments.

Olive trees are a major source of agricultural residues. Strategies based on different management of organic amendments have been reported to increase soil fertility. The effect of sustainable organic matter input practices (application of shredded pruning residue and olive residue compost to soil) on soil properties in irrigated and rain-fed olive groves was investigated. The study took place in 40 olive groves in the region of Peza, island of Crete, Greece during a 5-year period (2012–2017). The results showed that olive trees play an important role in soil nutrient conservation under semi-arid conditions in the Mediterranean basin. The addition of olive tree residues, in combination with conservation tillage practices, improved soil fertility over the experimental period. Most of the soil properties were favored by irrigation. In olive soil parcels receiving organic materials the soil organic matter and the total nitrogen were increased in irrigated fields. The ability of surface soil to sequester carbon and nutrients beneath the tree canopy of olive groves was high. It is recommended that sustainable soil management practices should consider soil fertility variability of olive orchards.

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.

The aim of the present study was to determine the short-term effects (three years) of four sustainable management systems including different carbon inputs (compost, pruning residues and cover crops, applied solely or combined) on the mineral content of soil, olive trees and weeds, on some specific groups of soil microorganisms, and on weed mycorrhizal colonization in an olive orchard compared to a conventional system involving soil tillage and only mineral forms of fertilizers. The study was performed between 2013 and 2015 in a 40-year-old olive plantation. The results showed that soil organic matter, as well as main macro- and micronutrients, were markedly improved following three years of increased biomass inputs. Data related to the mycorrhizal colonization of spontaneous weed flora and to actinobacteria, Azotobacter and proteolytic bacteria suggest favourable effects on soil biology and agro-ecosystem complexity. Sowing a mixture of winter cover crops for three successive years also contributed to soil enrichment in biological as well as mineral nutrient aspects. Adoption of the sustainable management here applied practices is in complete agreement with the European policy on the transition from a linear to a circular economy and would provide significant benefits for rural stakeholders and ecosystems in the long term.

A field experiment was conducted in an irrigated olive orchard to determine the effects of an orchard management system consisting of increased carbon input management on spatial distribution (tree...

Olive (Olea europaea L.) is a common cultivated tree crop in the Mediterranean Basin. Inappropriate cultivation practices (i.e. excessive tillage and application of herbicides, the absence of organic amendments, the burning of pruning residues in situ) lead, in combination with the Mediterranean climate, to the depletion of soil organic matter, erosion, desertification and degradation of water resources. Strategies based on changes in the land management (e.g. cover crops and green manure, restriction of tillage, recycling of agricultural wastes and pruning residues), have been reported to enhance soil structure, increase soil fertility, decrease soil erosion, increase the C stored in soil, and reduce atmospheric CO2. This chapter highlights soil management techniques that could promote the conservation of the productive olive grove system and thus contribute to the sustainability of the natural resources. During olive tree growth and olive oil production a large quantity of plant residues and mill wastes are produced. The implementation of alternative olive cultivation techniques (reduced/no tillage, plant residue and weed management, tree pruning, etc.) has not been systematically tested under the prevailing conditions of the Mediterranean olive forest. Although there are multiple specific studies taking into account specific practices in selected regions, a holistic approach for the Mediterranean olive groves has not yet been known. The design, the development and the adoption of an integrated soil management system in olive groves, adjustable to local soil climatic conditions is proposed, among further research priorities.

In this work, a dynamic GIS modeling approach is presented that incorporates: a) geoinformatic techniques, b) 55-year historical meteorological data, and c) field measurements, in order to estimate soil erosion risk in intensively cultivated regions. The proposed GIS-based modeling approach includes the estimation of soil erosion rates due to surface water flow under current and future climate change scenarios A2 and B1 for the years 2030 and 2050. The soil erosion was estimated using the Universal Soil Loss Equation (USLE). The proposed soil erosion model was validated using field measurements at different sites of the study area. The results show that an extended part of the study area is under intense erosion with the mean annual loss to be 4.85 t/ha year−1. Moreover, an increase in rainfall intensity, especially for scenario B1, can generate a significant increase (32.44 %) in soil loss for the year 2030 and a much more (50.77 %) for the year 2050 in comparison with the current conditions. Regarding the scenario A2, a slight decrease (1.85 %) in soil loss was observed for the year 2030, while for 2050 the results show an adequate increase (7.31 %) in comparison with the present. All these approaches were implemented at one of the most productive agricultural areas of Crete in Greece dominated by olive and citrus crops.

Olive growing counts as one of the most significant agricultural activities in Greece, from a financial, social and ecological point of view. Modern olive culture often includes exhaustive use of the available water resources having as a result adverse effects for production cost and the environment. This paper evaluates seasonal soil moisture content at three different soil depths (10, 30, 40 cm), in relation with rainfall and irrigation in an olive cultivar “Kalamon” orchard. Our results indicate strong variation of soil moisture as affected by season and irrigation. In addition, the role of drip-irrigation on soil moisture content appears to be more significant at soil depths up to 30 cm compared to lower soil zones. Specifically, at soil depth of 40 cm the soil moisture curves close to irrigation lines seems to coincide compared to these far away from the irrigation line.

Recycling Olive Mill Wastewater (OMW) by its application on agricultural land is considered to be a sustainable practice for soil enrichment and waste management, and recent legislation permits large scale OMW recycling in Mediterranean countries. Therefore, studies on the effects of OMW application on earthworms under experimental conditions that closely resemble those occurring in the field are urgently required to facilitate the safe and ecologically friendly use of OMW at large scale. In this study, the effects of three-phase OMW liquid on the survival and growth of the earthworm Octodrilus complanatus (Duges, 1828), commonly present in olive groves, were assessed. The liquid was applied at a rate i) equal to the maximum authorized by Greek legislation for olive groves fertilization (80 m3 ha−1) and ii) half of this amount (40 m3 ha−1). The effects were tested in an indoor experiment conducted in plastic containers. The results showed no adverse effect on the survival of the earthworms over a period of 56 days post-treatment, at both application doses. The growth of earthworms, as estimated by their body weight change at 28 or 56 days post-treatment, was not negatively affected; instead, there was a relative increase seen at the higher dose (80 m3 ha−1), although the difference between the treatments was not significant. Qualitative observations indicated feeding of earthworms on the OMW liquids. Organic matter decomposition was not affected and there was no significant alteration in the soil properties, except the electrical conductivity that was increased at the higher level of OMW application. Therefore, the application of OMW liquids at the doses recommended by the legislation does not affect the survival and growth of the earthworms and is compatible with their activities to promote organic matter decomposition.

Olive tree pruning residue and olive waste represent a great amount of organic materials that are produced during a short period. The application of organic materials to land is a common practice in sustainable agriculture in recent years. However, its implementation in olive groves under different irrigation regimes has not been systematically tested. The aim of this work was to study the effect of alternative carbon input techniques (e.g., wood shredded, pruning residues, returning of olive mill wastes the field with compost) on soil chemicals (e.g., pH, EC, total organic carbon, total nitrogen, inorganic nitrogen, humic and fulvic acids, available P, and exchangeable K), and microbial properties (e.g., soil basal microbial respiration and microbial biomass carbon) in relation to irrigation conditions (e.g., irrigated and rainfed olive orchards). The results showed that changes in soil quality in olive orchards due to carbon inputs depend on irrigation conditions. Soil carbon content remarkably reduced by the addition of organic material in irrigated plots compared to control whereas they were substantially increased in rainfed plots. Microbial parameters appeared to be reliable indicators of changes in soil management over the short period of this study. Nutrient concentrations and microbial properties of soil show a decreasing trend with increasing distance from tree trunk regardless the irrigation conditions and carbon input practices. This fact indicates the influence of a tree canopy area and root density on the soil surface properties. Soil depth significantly influenced soil attributes; major decreases were recorded for SOC, inorganic nitrogen, and microbial properties, indicating the high potential of surface soil in olive groves to sequester carbon. Conversely, the addition of organic matter and irrigation conditions did not contribute to subsoil C content. Proper management of alternative carbon inputs in soil can positively affect soil productivity in Mediterranean olive groves.