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Understanding differences in the agro‐hydrologic performance of Vertisols under conventional tillage (CT) and direct drill (DD) requires a thorough knowledge of the soil hydraulic properties. We measured water retention on 54 undisturbed topsoil (0–0.05 m) samples collected at the CT and DD plots from a long‐term experiment. Water retention was significantly larger in DD (p < .05) for absolute pressure heads (|h|) ranging from 63 to 3.2 × 103 cm, and at 1.8 × 104 and 3.3 × 104 cm. A comparison of the equivalent pore‐size distributions showed combined effects of tillage in the CT topsoil and compaction as a result of machinery traffic and natural consolidation in the DD topsoil, increasing and decreasing the amount of the largest pores in CT and DD, respectively, in favour of a larger abundance of smaller equivalent pore‐sizes in DD than in CT. Significant differences in water retention and abundance of equivalent pore sizes near the dry end of the soil water retention curve (|h| ≈ 4 × 104 cm) appear to be associated with the larger organic matter content in DD. These results were corroborated by field‐measured soil water content data (0–0.10 and 0.25–0.35 m), showing a persistently larger soil water content in DD than the spatial average of both tillage systems. Differences in the observed trimodal soil water content probability density functions between CT and DD were related to equivalent pore‐sizes for which significantly different water retentions were measured. This work elucidates direct and indirect effects of soil management on water retention and the equivalent pore‐size distribution, with important consequences for the soil´s agro‐hydrologic performance.

This study aims to analyze and systematize the recent judgments of the Supreme Court, interpreting article 108.3 of the Law 29/1998, of July 13th, regulating the contentious-administrative jurisdiction, drafting LO 7/2015, effective since October 1st, 2015. The precept obliges the judges, when ordering the demolition of a property, to demand as a prior condition, and barring imminent danger, the provision of sufficient guarantees to respond to the payment of indemnities owed to third parties in good faith. The typical assumption is the citizen who buys a home covered by an urban planning license, which is later declared illegal and his property as well, and must be demolished. In spite of the social and economic importance of the measure, the precept, being full of indeterminate legal concepts, provoked and provokes a multitude of questions about its meaning. Doubts that comes to palliate the Supreme Court in the sentences studied, although only partially., Este estudio pretende analizar y sistematizar las recientes sentencias del Tribunal Supremo interpretando el artículo 108.3 de la Ley 29/1998, de 13 de julio, reguladora de la jurisdicción Contencioso-administrativa, redacción LO 7/2015, vigente desde el 1 de octubre de 2015. El precepto obliga a los jueces, cuando ordena la demolición de un inmueble, a exigir como condición previa, y salvo peligro inminente, la prestación de garantías suficientes para responder del pago de las indemnizaciones debidas a terceros de buena fe. El supuesto típico es el ciudadano que compra una vivienda amparada en licencia urbanística, que es declarada posteriormente ilegal y su inmueble ilegalizable, debiendo ser demolida. Pues a pesar de la trascendencia social y económica de la medida, el precepto, al estar lleno de conceptos jurídicos indeterminados, provocó y provoca multitud de interrogantes sobre su sentido. Dudas que viene a paliar el Tribunal Supremo en las sentencias estudiadas, aunque sólo de manera parcial.

Mediterranean olive trees traditionally grow under rainfed conditions, on poor soils with steep slopes. Rainfall is mainly concentrated during autumn and winter and is characterized by intense rain pulses, separated by dry periods. The use of electromagnetic induction (EMI) techniques in these olive orchards might be questioned since EMI surveys are generally recommended to be performed under moist soil conditions. A 6.7 ha olive orchard was surveyed for EMI-based apparent electrical conductivity (ECa), both under wet and dry soil conditions. In addition, 48 soil samples were analyzed for soil texture and for soil water content (SWC) under both soil conditions. The relationships between ECa, soil texture and SWC, under both soil conditions were evaluated. Despite the significantly larger ECa values measured during the wet survey as compared to the dry survey, a similar spatial correlation structure was found, indicating temporally stable ECa patterns. Significant correlations (r) were found between both surveys for ECa (r = 0.67) and for SWC (r = 0.63). The correlation between SWC and clay content exceeded 0.60 for both surveys, and the correlation between ECa and clay content was twice as high under wet soil conditions as compared to dry soil. In both situations, the ECa surveys revealed the same patterns of soil texture, indicating that moist soil conditions are not an absolute prerequisite for the use of EMI to map the spatial variability of these soil properties. Nonetheless, measuring the ECa under different moisture conditions can provide additional information about soil moisture dynamics.

Olive cultivation is a widespread land use in Mediterranean climates. The proper implementation of soil and water conservation practices in groves requires detailed knowledge of the governing hydrological processes. In this work topsoil moisture dynamics under wet and dry conditions and across a small catchment was investigated in the inter row (IR) and directly under the olive tree canopies (UC). We do this using a sensor network (11 stations) and a simple bucket model which was calibrated (June, 2011–2012) and validated (June, 2012–2013). During most of the year the normalized soil moisture contents (s) were greater in the IR than under UC, with an average normalized soil moisture difference of 0.12. The difference between UC and IR normalized soil moisture followed a seasonal pattern, reaching a maximum near 0.30 during spring. An analysis of the normalized soil moisture probability density functions (pdfs) was bimodal, showing characteristic dominant wet and dry soil moisture states, with the highest probability densities for the dry state. Overall the spatial variability of soil moisture was lower UC than in the IR. This was a result of the soil moisture buffering capacity of the canopy with respect to rainfall and evaporation, in addition to observed differences in soil properties. Hourly soil moisture data were successfully modelled (R2 > 0.85), both UC and in the IR, yet with the inclusion of a simple formulation for canopy interception for the former. The results provide insight into how olive trees change hydrological processes in their neighbourhood. Copyright © 2016 John Wiley & Sons, Ltd.

Background and aims: Future success of olive cropping in the Mediterranean depends critically on improving yield, reducing production costs, and preventing infestation by soil-borne pathogens. In order to put forward adequate soil management practices accurate knowledge of the spatial distribution of soil properties is required. The aims of this study were to delimit areas with constrained tree development in an olive orchard using electromagnetic induction (EMI), and to identify the causal relationships between apparent electrical conductivity (ECa) and soil properties. Methods: The experimental field was exhaustively sampled for different soil properties and ECa was measured in 2011 and 2012 under dry and wetter soil conditions, respectively. Results: The spatial ECa distribution matched the observed canopy coverage pattern well. Three zones were delimited according to ECa values from 0 to 27.5, from 27.5 to 57.5, and greater than 57.5 mS m−1. All ECa signals, regardless of soil-water status, exhibited a common dominant ECa pattern. The area with the lowest ECa values (0–27.5 mS m−1) showed optimal tree growth (45 % canopy coverage) and presented significantly lower average clay contents than the other two areas. Intermediate ECa values (27.5–57.5 mS m−1) identified accurately the area with deficient tree development and tree die-off (12 % canopy coverage), and corresponded with an area along the drainage pathway where profile-averaged soil-water, clay, stone and organic matter content were highest. Conclusions: EMI surveys detected subtle differences in soil properties and provided useful information to delimit areas with constrained tree development. The approach can be used as a screening technique before installing tree plantations.

Despite the well-accepted value of soil hydraulic properties for describing and modeling matter and energy fluxes in the unsaturated zone, their accurate measurement across scales is still a daunting task. The increasing availability of continuous soil water content measurements at discrete points in space, as provided by sensor networks, offers still unexplored possibilities for evaluating soil physical properties across landscapes. In this study, we propose a new method, based on the Bruce and Klute equation, to estimate effective soil water diffusivity from soil water profile data observed during continuous desiccation periods. An analytical expression is proposed for the diffusion-soil water relationship, assuming an exponential relationship between soil water content and the Boltzmann variable. The method has been evaluated using soil water profile data observed at inter-row and under canopy locations across a rainfed olive orchard in SW Spain. The spatial variability of the effective soil water diffusivity across the orchard was estimated. Different soil conditions under the tree canopies as compared to inter-row areas resulted in significantly different effective diffusivity relationships, reflecting the effect of trees on soil physical properties and water dynamics across olive orchards. The proposed method offers a suitable alternative to traditional laboratory methods and can be easily extended to estimate soil hydraulic conductivity and water retention curves.

Soil erosion constitutes a major problem in the dry-farming agriculture of Mediterranean areas. The coincidence of fall showers falling over bare soils after a long, hot, dry summer, steep slopes, and intensive tillage, or the occurrence of large uncultivated patches like in tree-cropping, aggravate the problem. Among several soil conservation practices, cover crops are being adopted by olive farmers as a promising method to reduce soil and water losses. This report summarizes the results of 2 yr from a network of microplots installed in olive orchards in the olive-growing area of Southern Spain to improve the technique of soil management and extend it to farmers. The cover crop diminished soil losses in all the experimental plots with an average of 76%. Water loss was also reduced, although to a lesser extent, in six of the eight fields, with an average of 22%. Additionally, the results showed the great influence of the cover percentage in the decrease in soil loss and in the concentration of sediments in the runoff. However, it should be taken into account that plant cover consumes water, and that the advantages of the decrease in runoff in the water balance with the cover could be eliminated if it is not managed appropriately. Therefore, more years of experimentation covering different climate conditions are necessary. © Soil Science Society of America. All rights reserved.