Impact of soil erosion and runoff on mountain slopes of Mediterranean agroecosystems

La degradación de suelos en los agroecosistemas mediterráneos implica una pérdida de utilidad actual y una reducción de sus funciones potenciales, tanto por procesos naturales, como aquellos especialmente inducidos e intensificados por las acciones humanas. Se evalúa el impacto de la erosión y escorrentía en diferentes tipos de uso del suelo (TUS): agrícola (olivar, almendro y cereal), bosque (Pinus halepensis y Pinus sylvestris), matorral, pastizal y tierras de cultivo abandonadas, en Sierra Nevada (SE España). Las parcelas cerradas de erosión-escorrentía con dos repeticiones fueron instaladas en las laderas en cada TUS, registrándose tasas de erosión y escorrentía durante 22 eventos lluviosos. De acuerdo con los resultados obtenidos en el marco del presente estudio, los TUS consistentes en P. halepensis y P. sylvestris minimizaron de forma significativa la erosión y escorrentía, en contraste con los suelos agrícolas abandonados. En relación a los TUS con actividad agrícola se determinó una mayor incidencia de la erosión en el olivar respecto al almendro y cereal. El matorral registró tasas de erosión y escorrentía intermedia entre los Pinus spp. y agrícolapastizal. En consecuencia, la alteración de la cubierta vegetal es crucial para interpretar la degradación de la productividad de los suelos, así como para planificar estrategias sostenibles con el objeto de mitigar los procesos de degradación del suelo en agroecosistemas mediterráneos.Land degradation in Mediterranean agroecosystems implies the loss of current utility and reduction of its potential functions, by both natural processes and those specifically induced and intensified by human actions. The impact of erosion and runoff on different land-use types (LUT): farmland (olive, almond and cereal), forest (Pinus halepensis and Pinus sylvestris), shrubland, grassland and abandoned farmland in Sierra Nevada (SE Spain) have been assessed. The erosion plots twice replicated were located on the slopes for each land-use type, monitoring the erosion and runoff rates for 22 rainfall events. According to the results of the present study the LUT consisting in P. halepensis and P. sylvestris significantly minimized soil erosion and runoff, in contrast to the abandoned farmland. In relation to farmland activity important impact of erosion has been found in olive plots than in almond and cereal. The shrubland generated intermediate erosion and runoff rates between Pinus trees and agriculture-grassland plots. Consequently, plant cover change is crucial in interpreting the productivity degradation of soils, as well as in planning sustainable strategies to mitigate soil degradation processes in Mediterranean agroecosystems.Este trabajo fue realizado en el marco de los proyectos de investigación “Procesos hidrológicos y erosivos y valoración de la biomasa y secuestro de carbono orgánico bajo diferentes usos del suelo en la cuenca agraria “El Salado”, Lanjarón (SE España) (RTA2007-00008-00-00)” y “Técnicas de agricultura de conservación en cultivos leñosos de secano y clima mediterráneo: implicaciones en la productividad sostenible, control de la erosión, mantenimiento de la biodiversidad edáfica y la calidad de los suelos (RTA2011-00007-00-00)”, ambos otorgados por el INIA y cofinanciado con fondos FEDER de la UE

Gestión del conocimiento. Perspectiva multidisciplinaria. Volumen 10

El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 10, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro es una publicación internacional, seriada, continua, arbitrada de acceso abierto a todas las áreas del conocimiento, que cuenta con el esfuerzo de investigadores de varios países del mundo, orientada a contribuir con procesos de gestión del conocimiento científico, tecnológico y humanístico que consoliden la transformación del conocimiento en diferentes escenarios, tanto organizacionales como universitarios, para el desarrollo de habilidades cognitivas del quehacer diario. La gestión del conocimiento es un camino para consolidar una plataforma en las empresas públicas o privadas, entidades educativas, organizaciones no gubernamentales, ya sea generando políticas para todas las jerarquías o un modelo de gestión para la administración, donde es fundamental articular el conocimiento, los trabajadores, directivos, el espacio de trabajo, hacia la creación de ambientes propicios para el desarrollo integral de las instituciones

Mitigación de la erosión de suelos en plantaciones de almendro por cubiertas vegetales: implicaciones para la agricultura sostenible de montaña (SE España)

The conservation and sustainable management of soil and water resources are some of the biggest challenges in rainfed agricultural systems. During two hydrological years, we have studied the rates of erosion and soil runoff from hillside farming in three types of vegetation: barley (Hordeum vulgare), vetch (Vicia sativa) and thyme (Thymbra capitata), in an extensive planting of almond (Prunus amygdalus). The esperiment was conducted in Lanjaron (Granada, SE Spain) with closed erosion plots of 144 m2 (24 mx 6 m) on a hillside with a slope of 35%. Three meter wide vegetable strips were arranged intermittently and across the slope between rows of almond trees. The recordsof erosion and agricultural runoff were significantly lower in plots covered with thyme, in contrast to those recorded with vetch. The effectiveness of the thyme-covered over the barley and vetch ones in controlling erosion and runoff exceeded 69 and 67%, respectively. Cover crops while cutting and stopping the path of surface runoff retained transported sediments and promote their infiltration into the soil. Besides, the remaining runoff with much less energy can reinfiltrate on the ground before being intercepted by the next swath. We have concluded that the combination of growing woody plant and cover stripes represents an efficient model of adaptation to the traditional systems to improve productivity and sustainability of mountain agriculture in semiarid climate.La conservación y gestión sostenible de los recursos suelo y agua constituyen uno de los mayores retos de los sistemas agrícolas de secano. Durante dos años hidrológicos se han estudiado las tasas de erosión y escorrentía de un suelo de cultivo en ladera con tres tipos de cubierta vegetal: cebada (Hordeum vulgare), veza (Vicia sativa), y tomillo (Thymbra capitata) en una plantación extensiva de almendros (Prunus amygdalus). El ensayo se realizó en Lanjarón (Granada, SE España) con parcelas cerradas de erosión de 144 m2 (24 m x 6 m) en una ladera con pendiente del 35%. Las franjas vegetales de 3 m de ancho se dispusieron de forma intermitente y transversal a la pendiente entre hileras de árboles de almendro. Los registros de erosión y escorrentía agrícolas fueron significativamente inferiores en las parcelas con cubiertas de tomillo, en contraste con las registradas con veza. La efectividad de las cubiertas de tomillo respecto a las de cebada y veza en el control de erosión y escorrentía superaron el 69 y 67%, respectivamente. Las cubiertas vegetales al recortar y frenar la trayectoria de la escorrentía superficial retienen los sedimentos transportados y promueven su infiltración en el suelo. Asimismo, la escorrentía remanente con mucho menos energía puede reinfiltrarse en el suelo antes de ser interceptada por la siguiente franja. Se concluye que la asociación de cultivo leñoso con franjas de cubiertas vegetales representa un modelo eficiente de adaptación a los sistemas tradicionales para la mejora de la productividad y sostenibilidad de la agricultura de montaña de clima semiárido

High reduction of erosion and nutrient losses by decreasing harvest intensity of lavender grown on slopes

International audienc

High reduction of erosion and nutrient losses by decreasing harvest intensity of lavender grown on slopes

In Mediterranean countries, where rainfall is scarce and irregular, intensive agriculture promotes erosion and nutrient losses from soil, ending eventually in contamination of water bodies. Wild shrubs may protect the soil against the erosivity of raindrops. However, some shrubs such as wild lavender are traditionally harvested by uprooting the entire plant. Thus, we studied here the impact of harvesting only a part of the plant biomass. Cultivating lavender, Lavandula lanata L., in erosion plots in Lanjarón, Granada, Spain, we studied the effect of two harvest intensities of 25% and 50% of the plant biomass, on soil erosion, runoff, nutrient loss (NPK) and soil-water dynamics. Our results show that decreasing the harvest intensity from 50% to 25% reduced soil loss by 67%: from 143 to 46 kg soil ha$^{-1 }$yr$^{-1}$. Water runoff was also decreased by 59%: from 13 to 5 mm yr$^{-1}$. These findings demonstrate that the rational harvest of cultivated aromatic plants protected the soil against erosion due to the reduction of soil-particle detachment by raindrop impact, and consequently avoided mechanical soil movement. Further, decreasing the harvest intensity from 50% to 25% reduced N losses by 65%, P losses by 42% and K losses by 64%. Soil-water content at 5, 10 and 20 cm deep was also higher for a harvest intensity of 25% than for a harvest intensity of 50%. In conclusion, this study supports the cultivation of lavender instead of wild harvest, following a rational harvest of biomass for reducing erosion and pollution as well as conserving soil-water content

La fruticultura subtropical en los ecosistemas de ladera de clima mediterráneo: cambios en la vegetación/Subtropical fruit farming in Mediterranean weather hillside ecosystem: changes in vegetation

En la costa de Granada, sureste de España, se encuentra una zona de frutales subtropicales en laderas, distribuidos en terrazas. Se evaluaron tasas de descomposición y liberación de nitrógeno (N) de hojarasca, en dos ecosistemas: (1) ecosistema de ladera inalterado (ELI) sin cultivo agrícola, con cubierta de vegetación autóctona, y (2) ecosistema de ladera alterado (ELA) con frutales de mango (Mangifera indica L.), aguacate (Persea americana Mill.), chirimoyo (Annona cherimolia Mill.), níspero (Eriobotrya japonica (Thunb.) Lindl.), y cubiertas de plantas aromáticas y medicinales (PAM) en los taludes de las terrazas. En ELA la tasa de descomposición de hojarasca de chirimoyo fue la más alta, y entre las PAM la alhucema rizada (Lavandula dentata L.), así como la mejorana (Thymus mastichina L.), alhucema rizada (Lavandula dentata L.) y ajedrea (Satureja obovata Lag.) registraron altas tasas de liberación de N. En ELI acebuche (Olea europea L.) y bolina (Genista umbellata (L'Hér.) Dum., tuvieron bajas tasas de descomposición. Las PAM en ELA pueden contribuir a restablecer los ciclos naturales de reciclado de nutrientes, minimizando los efectos del cambio de uso del suelo

WABOL: A conceptual water balance model for analyzing rainfall water use in olive orchards under different soil and cover crop management strategies

A water balance model developed to simulate the effect of different soil management alternatives, as for instance conventional tillage or cover crop, on soil water balance has been implemented in a user friendly interface in order to allow its use by technicians and other stakeholder in the olive sector. In spite of this simplified interface for the user, the model uses process-based methodologies to describe the key processes controlling water balance in rainfed olive orchards, such as runoff, deep percolation, cover crop growth, soil evaporation and olive and cover crop transpiration. Model predictions were evaluated using 3-year period of runoff and soil moisture data for different soil managements from an experimental field located in an olive orchard in Southern Spain. Comparison of simulated results with experimental data suggests that the model predicts satisfactorily runoff losses and soil moisture. Thus, annual runoff simulation provided a RMSE of 4.4 mm and the model efficiency was in general higher than 0.5. This suggests that the described model could be a useful tool for stakeholders to carry out a complete evaluation of different soil management alternatives in olive orchards. Finally, an example of an application of the model is presented. In this example, the model is used to evaluate the impact of using a cover crop, including different mowing dates, on the different components of the soil water balance compared to conventional tillage for the conditions of Cordoba, Southern Spain, using a 50 year long record. This exercise indicates that the use of a cover crop in these conditions have a negative impact on olive transpiration (25% average reduction), although this impact can be mitigated using an early date killing of the cover crop, March 15th for the conditions simulated in this exercise.The authors wish to thank P08-AGR-03643 (Andalusian Government), AGL2009-12936-C03-01 (Spanish Ministry of Science and Innovation) and FEDER funds (Spanish Ministry for Agriculture, Food and the Environment) for its support in some of the phases of our study. We also acknowledge the Fund for Excellence of the Ministry of Education and Science of the Albanian government which supported the stay of the corresponding author at IAS-CSIC during this collaboration.Peer Reviewe

Organic olive farming in Andalusia, Spain. A review

AbstractOlive is a key crop in the Mediterranean basin, socially, economically, and environmentally, being a major source of rural employment. Organic products such as olive oil have attracted many types of consumers in recent years. In this context, the Mediterranean basin represents 5 Mha of the 10 Mha of olive farming worldwide, with Spain being the leading producer. Also, during the recent decades, olive farmers met the challenges of sustainability by implementing principles of agroecological production. Therefore, the focal point is no longer exclusively on yields but also on the quality, health, and environmental aspects of products and systems. In this work, we review and analyse the global situation of organic farming, focusing on the development, current status, perspectives, and opportunities of organic olive farming in Andalusia (S Spain). In addition, we assess the environmental benefits and consequences of the shift from conventional to organic management of olive orchards, focusing on the improvement of soil quality and biodiversity. Also, the general factors affecting the decision making for acquiring organic olive oil are discussed. Our main findings show the following: (1) It is necessary to encourage educational and research programmes to promote the demand for these products, positively affecting consumer health, protecting the environment, and improving rural economies. (2) The future of organic agriculture will depend on its economic viability and on the determination shown by governments to protect these practices. (3) Further support for funding research is needed to continue studying the effect of olive cultivation on soil biological quality, changes in soil properties, and biodiversity. More importantly, these beneficial extra outputs produced for society must be interiorised in economic value to compensate organic oil producers. (4) Finally, a clear understanding of attitudes and preferences, as well as the motivations of consumer when making the choice for organic olive products, is essential in responding to this specific demand. However, as stated above, major institutional and educational actions are also needed in order to boost sustainable organic olive farming and thus the preference for organic olive oil

Benefits of plant strips for sustainable mountain agriculture

Erosion degrades soil quality in agricultural ecosystems, thereby reducing the productivity of the land. Semi-natural vegetation and diverse cropping systems have been converted into monocultures with low tree densities, leaving the soil unprotected. We evaluated the association in soil- and water-conservation systems with production in traditional almond orchards and the beneficial impact of plant strips in mountainous agriculture. Soil loss, runoff and nutrient loss over a four-year period (2002–2005) were monitored in hillside erosion plots with almond trees under different soil-management systems: (1) non-tillage with sage (Salvia lavandulifolia L. subspecies Oxyodon) strips 3 m wide; (2) non-tillage with rosemary (Rosmarinus officinalis L.) strips, (3) non-tillage with thyme (Thymus baeticus L. Boiss. exlacaita) strips, and (4) conventional tillage on the south flank of the Sierra Nevada (Lanjaron) in south-eastern Spain. Also, the nut yield from almond trees, and the biomass from aromatic-shrub strips were measured. The erosion plots, located on a 35% slope, were 144 m$^{2}$ in area. The plant-cover strips, 3 m wide, ran across the slope. Our results show that the most effective treatment proved to be non-tillage with thyme strips, reducing the annual soil loss by 93% and runoff by 80%, with respect to conventional tillage. Non-tillage with rosemary strips reduced soil loss by 91% and runoff by 82%, with respect to conventional tillage, while these percentages were 69% and 51%, respectively, for non-tillage with sage strips. In addition, all the treatments as a whole, in comparison with conventional tillage, revealed that the plant strips were the decisive factor in the reduction of NPK losses by surface runoff. The average nut yield from non-tillage with sage strips, non-tillage with rosemary strips, non-tillage with thyme strips and conventional tillage during the study period was 2.4, 3.2, 3.8 and 4.5 kg tree$^{-1}$, respectively, and the essential oil yield from sage, rosemary and thyme strips was 5.0, 8.7 and 10.8 L ha$^{-1}$, respectively. The non-tillage with thyme strips decreased nutrient loading in surface waters and thus had a positive impact on the environment while simultaneously maintaining reasonable almond-production levels. Thus, the combination of orchard trees with shrubs provided a viable option to conserve soil and water in hilly areas with opportunities to increase overall land productivity as well as sustainable agro-environmental measures

Dynamic of Carbon and Nitrogen Concentrations in the Decomposition of Leaf Litter of Subtropical Crops in Southeastern Spain

Litter decomposition is one on the main routes of energy consume in an ecosystem and one of the principal roles in nutrient cycling. On the other side, in the last decades, subtropical crops have expanded importantly along the coast of Granada (SE Spain). To evaluate the cycles a bag technique experiment was carried out by using mango leaves (Mangifera indica L.), cherimolia (Annona cherimola Mill.), avocat (Persea americana Mill.) and loquat (Eriobotrya japonica L.). The main objective of this work was monitoring the dynamic of litter decomposition of these crops leaves and the evolution of their contents in carbon and nitrogen in a Mediterranean subtropical climate context. Bags were buried and recovered at certain time periodically to evaluate carbon and nitrogen concentration as well as mass losses. The results of this study showed that farmers could benefit of the knowledge of nutrient dynamics in litter decomposition to improve soil organic matter in the long term and to incorporate nitrogen. In this sense, loquat and mango showed the highest nitrogen accumulation and as a consequence these types of litters could be used as organic soil amendments in the long term. Contrarily, cherimolia accumulated higher carbon amounts than the rest of the studied crops