The age of vines as a controlling factor of soil erosion processes in Mediterranean vineyards

Vineyards incur the highest soil and water losses among all Mediterranean agricultural fields. The state-of-the-art shows that soil erosion in vineyards has been primarily surveyed with topographical methods, soil erosion plots and rainfall simulations, but these techniques do not typically assess temporal changes in soil erosion. When vines are planted they are about 30 cm high × 1 cm diameter without leaves, the root system varies from 2 to over 40 cmdepth, and sometimes the lack of care used during transplanting can result in a field with highly erodible bare soils. This means that the time since vine plantation plays a key role in soil erosion rates, but very little attention has been paid to this by the scientific community. Thus, the main goal of this research was to estimate soil losses and assess soil erosion processes in two paired vineyard plantations of different ages. To achieve this goal, the improved stock unearthing method (ISUM) was applied to vineyards on colluvial parent materials with similar soil properties, topographical characteristics and landmanagements in the Les Alcusses Valley, southwestern Valencia province, Spain. Our findings suggested that the old vineyards showed lower erosion rates (−1.61 Mg ha−1 yr−1) than those that were recently planted (−8.16 Mg ha−1 yr−1). This is because of the damage that the plantation of the vines causes to soil. Tillage after planting (4 times per year) resulted in changes in the inter-rowand rowmorphology, promoting the development of a ridge underneath the vines that disconnected the inter-rows and reduced soil losseswith time. After the second year and until the 25th year after plantation, soil erosionwas approximately 1Mg ha−1 y−1,whichmeans thatmost of the erosion took place during the first two years after the plantation. Soil conservation strategies should be applied immediately after the plantationworks to allow sustainable grape production. That is when soil erosion most needs to be controlled

The Contrasted Impact of Land Abandonment on Soil Erosion in Mediterranean Agriculture Fields

Abandonment of agricultural land results in on- and off-site consequences on soil system and there is a need to evaluate the impact on soil erosion to understand the ecosystem's changes. The aim of this research is to assess the impact of abandonment in four Mediterranean crops (vineyards, almonds, citrus and olives) on soil and water losses. To achieve this goal, 105 rainfall simulation experiments were conducted in agriculture fields (vineyards in Málaga, almonds in Murcia, and citrus and olive in Valencia) and on the paired abandoned plots. After abandonment, soil detachment decreased drastically in the olive and citrus orchards, meanwhile vineyards did not show any difference and almonds registered higher erosion rates after the abandonment. Terraced orchards of citrus and olives recovered a dense vegetation cover after the abandonment, meanwhile the sloping terrain of almonds and vineyards enhanced the development of crusts and rills and a negligible plant cover that resulted in high erosion rates. The contrasted response of the abandonment is discussed

Role of rock fragment cover on runoff generation and sediment yield in tilled vineyards.

The soil in conventional Mediterranean vineyards is an active and non-sustainable source of sediment and water. Lack of vegetation cover, small soil organic matter content and intense ploughing result in large rates of erosion in a millennia-old tillage system. There is a need for soil conservation strategies that enable sustainability of wine and grape production; therefore, it is essential to measure the rates and to investigate the processes and factors of soil erosion. This study evaluated factors that can reduce soil losses in traditional Mediterranean vineyards. The investigation was carried out with 96 rainfall simulation experiments at the pedon scale (0.24m2) to measure soil detachment and runoff yield under low frequency-high magnitude rainfall events of 1 hour at 55mmhour−1. On average, runoff was 40.6% of the rainfall, and the rate of soil erosion (i.e. amount of soil lost) was 71.5 g m−2. The key factor controlling erosion was the rock fragment cover. There was a clear decrease in soil losses with increased rock fragment cover on the soil surface, but an increase in surface runoff. The results of our study showed that rock fragments at the pedon scale reduced soil erosion in Mediterranean vineyards, but when a layer of embedded rock fragments developed, large rates of runoff were triggered

Effects of parent material on soil erosion within Mediterranean new vineyard plantations

Parent material can determine specific physical and chemical soil properties and, therefore, soil erosion rates. However, for new vine plantations, there is not enough research on soil erosion assessment on different parent materials which could be helpful for agricultural management plans. The main aim of this research was to quantify soil erosion rates of two recent vineyard plantations under similar climate and land use management conditions, but on different parent materials, namely colluvium (2 years old) and marls (8 years old), located within the Les Alcusses valley vineyards in Eastern Spain. To achieve this goal, the ISUM (improved stock unearthing method) was applied. ISUM involves measurements of vertical distances from a horizontally stretched meter band attached to opposite pair vine plants to the topsoil surface at 5 sampling points along the cross sections of the pair vine rows. The original surface level was determined from the fixed distance of 2 cm of the graft unions from the soil surface. Digital elevation modelling of the vertical measurements was used to infer the erosion rates. Annual total soil erosion rates were 87.7 Mg ha−1 year−1 and 4.35 Mg ha−1 year−1 in the marls and colluvium plots, respectively. For the marls plot, 67% of the depletion occurred in the inter-row areas, whereas for the colluvium plot the inter-row areas registered 4.78 Mg ha−1 year−1 depletion and the row areas showed only a deposition of 0.44 Mg ha−1 year−1. We hypothesised that the inter-row areas registered the highest erosion rates due to the tillage practices. In the row areas, the cover of the vines possibly reduced soil erosion rates and acted as sinks for sediments. This behaviour of the inter-row areas acting as sources and the row areas as sinks for sediments was more evident on the colluvium plot, while most sections on the marls plot showed intense erosion features. It is suggested that more attention should be paid by policymakers and stakeholders to these differences when new plantations are introduced on marls and colluvium vineyards. We claim that initial soil erosion control measures should be applied during the first few years of plantations instead of when the vineyards are much older and soil has already been mobilised

Evaluation of multi-hazard map produced using MaxEnt machine learning technique

Natural hazards are diverse and uneven in time and space, therefore, understanding its complexity is key to save human lives and conserve natural ecosystems. Reducing the outputs obtained after each modelling analysis is key to present the results for stakeholders, land managers and policymakers. So, the main goal of this survey was to present a method to synthesize three natural hazards in one multi-hazard map and its evaluation for hazard management and land use planning. To test this methodology, we took as study area the Gorganrood Watershed, located in the Golestan Province (Iran). First, an inventory map of three different types of hazards including flood, landslides, and gullies was prepared using field surveys and different official reports. To generate the susceptibility maps, a total of 17 geo-environmental factors were selected as predictors using the MaxEnt (Maximum Entropy) machine learning technique. The accuracy of the predictive models was evaluated by drawing receiver operating characteristic-ROC curves and calculating the area under the ROC curve-AUCROC. The MaxEnt model not only implemented superbly in the degree of fitting, but also obtained significant results in predictive performance. Variables importance of the three studied types of hazards showed that river density, distance from streams, and elevation were the most important factors for flood, respectively. Lithological units, elevation, and annual mean rainfall were relevant for detecting landslides. On the other hand, annual mean rainfall, elevation, and lithological units were used for gully erosion mapping in this study area. Finally, by combining the flood, landslides, and gully erosion susceptibility maps, an integrated multi-hazard map was created. The results demonstrated that 60% of the area is subjected to hazards, reaching a proportion of landslides up to 21.2% in the whole territory. We conclude that using this type of multi-hazard map may be a useful tool for local administrators to identify areas susceptible to hazards at large scales as we demonstrated in this research

A Conceptual Model for Planning and Management of Areas of Public Space and Meeting in Colombia

A refined investigation of new trends in urban analysis assuming a sustainable design of Areas of Public Space and Meeting (APSM) is a fundamental response to the challenges of inclusive and efficient cities. Even though the APSM are districts regarded as urban structuring systems, there is a lack of territorial planning instruments and conceptual models aimed at explaining their long-term dynamics. Based on these premises, we developed a conceptual model that articulates relevant variables of interest for the planning and management of APSM. The construction of the model includes the review and analysis of the literature and the validation process based on a consultation with a panel of experts on the subject. Our findings demonstrate that the existing research does not address the APSM issue adequately, and the methodologies proposed so far do not lead to accurate and comprehensive analyses of urban complexity in light of sustainability targets. There are only isolated, disjointed, and partial approaches to variables of interest, making it difficult to carry out holistic studies. Our technical and scientific proposal offers a framework for an exhaustive evaluation of these areas. The model has been structured according to the assumptions of urban sustainability and can be applied to diverse urban environments in South America

Soil degradation and socioeconomic systems’ complexity: Uncovering the latent nexus

Understanding Soil Degradation Processes (SDPs) is a fundamental issue for humankind. Soil degradation involves complex processes that are influenced by a multifaceted ensemble of socioeconomic and ecological factors at vastly different spatial scales. Desertification risk (the ultimate outcome of soil degradation, seen as an irreversible process of natural resource destruction) and socioeconomic trends have been recently analyzed assuming “resilience thinking” as an appropriate interpretative paradigm. In a purely socioeconomic dimension, resilience is defined as the ability of a local system to react to external signals and to promote future development. This ability is intrinsically bonded with the socio-ecological dynamics characteristic of environmentally homogeneous districts. However, an evaluation of the relationship between SDPs and socioeconomic resilience in local systems is missing in mainstream literature. Our commentary formulates an exploratory framework for the assessment of soil degradation, intended as a dynamic process of natural resource depletion, and the level of socioeconomic resilience in local systems. Such a framework is intended to provide a suitable background to sustainability science and regional policies at the base of truly resilient local systems

Population trends and urbanization. Simulating density effects using a local regression approach

7siopenDensity-dependent population growth regulates long-term urban expansion and shapes distinctive socioeconomic trends. Despite a marked heterogeneity in the spatial distribution of the resident population, Mediterranean European countries are considered more homogeneous than countries in other European regions as far as settlement structure and processes of metropolitan growth are concerned. However, rising socioeconomic inequalities among Southern European regions reflect latent demographic and territorial transformations that require further investigation. An integrated assessment of the spatio-temporal distribution of resident populations in more than 1000 municipalities (1961-2011) was carried out in this study to characterize density-dependent processes of metropolitan growth in Greece. Using geographically weighted regressions, the results of our study identified distinctive local relationships between population density and growth rates over time. Our results demonstrate that demographic growth rates were non-linearly correlated with other variables, such as population density, with positive and negative impacts during the first (1961-1971) and the last (2001-2011) observation decade, respectively. These findings outline a progressive shift over time from density-dependent processes of population growth, reflecting a rapid development of large metropolitan regions (Athens, Thessaloniki) in the 1960s, to density-dependent processes more evident in medium-sized cities and accessible rural regions in the 2000s. Density-independent processes of population growth have been detected in the intermediate study period (1971-2001). This work finally discusses how a long-term analysis of demographic growth, testing for density-dependent mechanisms, may clarify the intrinsic role of population concentration and dispersion in different phases of the metropolitan cycle in Mediterranean Europe.openPolinesi G.; Recchioni M.C.; Turco R.; Salvati L.; Rontos K.; Rodrigo-Comino J.; Benassi F.Polinesi, G.; Recchioni, M. C.; Turco, R.; Salvati, L.; Rontos, K.; Rodrigo-Comino, J.; Benassi, F

Straw mulch as a sustainable solution to decrease runoff and erosion in glyphosate-treated clementine plantations in Eastern Spain. An assessment using rainfall simulation experiments

[EN] In many Mediterranean areas, citrus orchards exhibit high soil loss rates because of the expansion of drip irrigation that allows cultivation on sloping terrain and the widespread use of glyphosate. To mitigate these non-sustainable soil losses, straw mulch could be applied as an efficient solution but this has been poorly studied. Therefore, the main goal of this paper was to assess the use of straw mulch as a tool to reduce soil losses in clementine plantations, which can be considered representative of a typical Mediterranean citrus orchard. A total of 40 rainfall simulation experiments were carried out on 20 pairs of neighbouring bare and mulched plots. Each experiment involved applying 38.8 mm of rain at a constant rate over 1 h to a circular plot of 0.28 m(2) circular plots. The results showed that a cover of 50% of straw (60 g m(-2)) was able to delay the time to ponding from 32 to 52 s and the time to runoff initiation from 57 to 129 s. Also, the mulching reduced the runoff coefficient from 65.6 to 50.5%. The effect on sediment transport was even more pronounced, as the straw mulch reduced the sediment concentration from 16.7 g l(-1) to 3.6 g l(-1) and the soil erosion rates from 439 g to 73 g. Our results indicated that mulching can be used as a useful management practice to control soil erosion rates due to the immediate effect on high soil detachment rate and runoff initiation reduction in conventional clementine orchards on sloping land, by slowing down runoff initiation and by reducing runoff generation and, especially, sediment losses. We indirectly concluded that straw mulch is also a sustainable solution in glyphosate-treated citrus plantations.This paper is part of the results of research projects GL2008-02879/BTE, LEDDRA 243857 and RECARE-FP7 (ENV.2013.6.2-4).Keesstra, S.; Rodrigo-Comino, J.; Novara, A.; Giménez Morera, A.; Pulido, M.; Di Prima, S.; Cerda, A. (2019). Straw mulch as a sustainable solution to decrease runoff and erosion in glyphosate-treated clementine plantations in Eastern Spain. An assessment using rainfall simulation experiments. CATENA. 174:95-103. https://doi.org/10.1016/j.catena.2018.11.007S9510317