Search

The need to improve agroecosystem sustainability to secure yields, minimize environmental impacts and improve soil health is widely recognized. Organic production systems are one of the strategies that may be used to alleviate the negative environmental repercussions of conventional agriculture. In the present study, we compared the impact of conventional and organic production systems on the almond (Prunus dulcis (Mill.) D.A. Webb) yield and quality of nuts of two cultivars (Marcona and Desmayo largueta), with both systems being managed on marginal hillslopes in the southeast of Spain. Our findings show that the organic production system in rainfed almond trees has positive effects on certain nut quality parameters, with a slight decrease in almond yield, specifically 9.5% for cv. D. largueta and 1.3% for cv. Marcona, with respect to the conventional system. The results obtained have varied depending on the cultivar. Statistically significant differences have been obtained for cv. Marcona in the sugar content (54.4 and 49.8 g kg−1 in organic and conventional, respectively) and the total phenol content (3.41 and 2.46 g GAE kg−1 for organic and conventional, respectively). In the case of cv D. largueta, statistically significant differences were found between the organic and conventional systems for antioxidant activity (14.8 vs. 8.68 mmol Trolox kg−1, DPPH), fatty acid content (229 vs. 188 g kg−1 dw), saturated fatty acids (36 vs. 28.7 g kg−1 dw), monounsaturated fatty acids (113 vs. 110 g kg−1 dw) and polyunsaturated fatty acids (60.3 vs. 49.6 g kg−1 dw ). Here, we show for the first time how a rainfed organic system allows for higher- quality almonds, specifically with a higher content of phytochemicals beneficial for health, which, together with the higher price compared to conventional almonds, could compensate for the yield losses while preserving the sustainability of marginal agroecosystems.

El cambio climático, la reducción de los recursos hídricos o la degradación y el abandono de la tierra son algunas de las limitaciones que hay que superar en la búsqueda de una agricultura competitiva y sostenible. Dentro de las posibles estrategias, debe considerarse la implementación de cultivos tolerantes a la sequía con alta rentabilidad y la implementación de estrategias de ahorro de agua como las estrategias de riego deficitario (RD). Dentro de las posibilidades de cultivo, el almendro (Prunus dulcis Mill.) sería una excelente alternativa ante un escenario de escasez de agua y cambio climático. Sin embargo, es esencial alcanzar un equilibrio entre la gestión de cultivos y la disponibilidad de agua, definiendo sus necesidades hídricas y las relaciones entre las necesidades de riego y las prácticas agronómicas. En este sentido el objetivo general de esta tesis doctoral fue mejorar el manejo del riego del cultivo del almendro, concretamente en tres de las variedades más implementadas en el sector almendrero (cvs. Guara, Marta y Lauranne) usando dos estrategias de RD diferentes; riego deficitario controlado (RDC) y riego deficitario sostenido (RDS). Con el objetivo de optimizar el manejo del agua de riego para cada variedad estudiada y aumentar la calidad de la almendra obtenida. El estudio se llevó a cabo en dos fincas comerciales de almendro; “Montana de San José” y “Cartuja”. En la primera finca los experimentos se llevaron a cabo durante las campañas 2017 y 2018 y se estableció tres tratamientos de riego: Control (FI); el cual se rego al 100% de las necesidades de riego (NR) durante todo el periodo de riego (PR), un tratamiento sobre regado (150-ETc); el cual se regó al 150% NR durante todo el periodo de riego y un tratamiento de RDC (RDC65) el cual se regó cubriendo el 100% de las NR excepto en los meses de llenado de grano donde se regó al 65% de las NR. En la segunda, los experimentos se llevaron a cabo en las campañas 2019 y 2020 y se establecieron tres tr

Almond (Prunus dulcis Mill. [D.A. Webb]) is the third most widely spread crop in Spain and has traditionally been cultivated in marginal areas and shallow soils under rainfed conditions. However, it recently has been progressively introduced in flat irrigated areas. The implementation of cover crops in the inter-rows of woody crops has been proven as a suitable strategy to reduce the runoff and soil erosion but they also can boost soil quality and health. A field experiment was conducted during two-monitoring seasons to examine the soil nitrogen and carbon sequestration potential of three seeded cover crops [barley (Hordeum vulgare L.), hairy vetch (Vicia villosa Roth), and a mixture of 65% barley and 35% vetch] and a control of spontaneous flora in irrigated almond orchards (SW Spain). Here, we show that barley provided the highest biomass amount, followed by mixture covers, vetch, and the control treatment. Also, vetch covered the soil faster in the growing stage, but its residues were decomposed easier than barley and mixture treatments during the decomposition period after mowing, providing less soil protection when the risk of water erosion with autumn rainfall is high. On the other hand, vetch improved soil nitrate content by over 35% with respect to barley and mixture treatments at 0–20 cm soil depth throughout the studied period. In addition, a greater carbon input to the soil was determined in the barley plot. That is, the mixture and barley cover crops had higher potential for carbon sequestration, augmenting the soil organic carbon by more than 1.0 Mg ha−1 during the study period. Thus, taking into consideration the findings of the present experiment, the establishment of a seeded cover crop would be more advisable than spontaneous flora to mitigate soil erosion, enhancing soil fertility and carbon sequestration in irrigated almond plantations in Mediterranean semi-arid regions.

The demand for aromatic and medicinal plants (AMPs) is growing worldwide, and most of them are from the wild collection. Today there is a consensus that for industrial purposes the AMPs must be cultivated. Many studies have shown the importance of the collection strategy used to guarantee the plant regeneration, and soil protection against erosion process in mountainous areas in the Mediterranean region. In this work, during three-year monitoring period we compared in four AMPs two harvest strategies by cutting biomass in 25% (BHI25) and 50% (BHI50) of oregano (Origanum bastetanum L.), lavender (Lavandula lanata L.); sage (Salvia lavandulifolia V.); and santolina (Santolina rosmarinifolia L.) in order to assess their effect on essential-oil content, and to be consistent with both plant and soil conservation in Mediterranean steeply sloping areas. The experimental plots were located in Lanjarón (Granada, SE Spain), on a 20% slope. According to the findings the strategy BHI50 of fresh herb of oregano, lavender, sage, and santolina produced essential-oil yield of 13.2 ± 1.74, 17.3 ± 1.69, 9.7 ± 5.21, and 10.8 ± 2.00 L·ha-1, respectively. Since significant differences were found between BHI25 and BHI50 strategies for harvest and distillation of aromatic plants, we recommend a rational harvest, leaving the 50% of the plant biomass in the field to avoid the soil degradation. In addition, with this rational harvest strategy encourages the sustainable AMP cultivation without significant alterations for essential-oil yields, and at the same time guaranteeing the regrowth, and conservation of them in its habitat. Therefore, encouragement local decision-making measures regarding environmental compatibility, social acceptability and economic viability in land use and management will be crucial. Otherwise, the inappropriate harvest of aromatic shrubs in mountain areas compromises land conservation.

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., La descomposición de la hojarasca es una de las principales vías de consumo de energía en un ecosistema y uno de los pilares básicos en el ciclo de nutrientes. Por otro lado, en las últimas décadas, los cultivos subtropicales se han expandido de forma considerable en la costa de Granada (sureste de España). Para evaluar dichos ciclos se llevó a cabo un ensayo con bolsas utilizando para ello hojas de mango (Mangifera indica L.), chirimoyo (Annona cherimola Mill.), aguacate (Persea americana Mill.) y níspero (Eriobotrya japonica L.). El objetivo de este trabajo fue realizar un seguimiento de la dinámica de descomposición de las hojarascas producidas por el mango, aguacate, chirimoyo y níspero, y de la evolución de su contenido en carbono y nitrógeno en condiciones de clima mediterráneo subtropical. Las bolsas fueron enterradas y se recuperaron cada cierto tiempo para evaluar la concentración de carbono y nitrógeno, así como la pérdida de masa en cada una de ellas. Los resultados de este estudio mostraron de forma evidente que los agricultores pueden beneficiarse del conocimiento de la dinámica de nutrientes en hojarasca para mejorar la materia orgánica en el suelo a largo plazo y la incorporación de nitrógeno. En este sentido, el níspero y el mango mostraron las mayores tasas de acumulación de nitrógeno y, por lo tanto, la biomasa de estas especies podría ser utilizada como enmiendas de tipo orgánico a largo plazo. Por el contrario, el chirimoyo acumuló mayores cantidades de carbono que el resto de los cultivos estudiados.

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., La descomposición de la hojarasca es una de las principales vías de consumo de energía en un ecosistema y uno de los pilares básicos en el ciclo de nutrientes. Por otro lado, en las últimas décadas, los cultivos subtropicales se han expandido de forma considerable en la costa de Granada (sureste de España). Para evaluar dichos ciclos se llevó a cabo un ensayo con bolsas utilizando para ello hojas de mango (Mangifera indica L.), chirimoyo (Annona cherimola Mill.), aguacate (Persea americana Mill.) y níspero (Eriobotrya japonica L.). El objetivo de este trabajo fue realizar un seguimiento de la dinámica de descomposición de las hojarascas producidas por el mango, aguacate, chirimoyo y níspero, y de la evolución de su contenido en carbono y nitrógeno en condiciones de clima mediterráneo subtropical. Las bolsas fueron enterradas y se recuperaron cada cierto tiempo para evaluar la concentración de carbono y nitrógeno, así como la pérdida de masa en cada una de ellas. Los resultados de este estudio mostraron de forma evidente que los agricultores pueden beneficiarse del conocimiento de la dinámica de nutrientes en hojarasca para mejorar la materia orgánica en el suelo a largo plazo y la incorporación de nitrógeno. En este sentido, el níspero y el mango mostraron las mayores tasas de acumulación de nitrógeno y, por lo tanto, la biomasa de estas especies podría ser utilizada como enmiendas de tipo orgánico a largo plazo. Por el contrario, el chirimoyo acumuló mayores cantidades de carbono que el resto de los cultivos estudiados., A decomposição do folhedo é uma das principais vias de consumo de energia em um ecossistema e um dos pilares básicos no ciclo de nutrientes. Por outro lado, nas últimas décadas, os cultivos subtropicais têm se expandido de forma considerável na costa de Granada (sudeste da Espanha). Para avaliar tais ciclos foi levado a cabo um ensaio com sacolas utilizando para isso folhas da mangueira (Mangifera indica L.), anoneira (Annona cherimola Mill.), abacateiro (Persea americana Mill.) e nespereira (Eriobotrya japonica L.). O objetivo deste trabalho foi realizar um seguimento da dinâmica de decomposição dos folhedos produzidos pela mangueira, pelo abacateiro, pela anoneira e nespereira, e da evolução de seu conteúdo em carbono e nitrogênio em condições de clima mediterrâneo subtropical. As sacolas foram enterradas e retiradas a cada certo tempo para avaliar a concentração de carbono e nitrogênio, como também a perda de massa em cada uma delas. Os resultados deste estudo mostraram, de forma evidente, que os agricultores podem ser beneficiados pelo conhecimento da dinâmica de nutrientes em folhedos para melhorar a matéria orgânica no solo em longo prazo e a incorporação de nitrogênio. Neste sentido, as folhas da nespereira e da mangueira mostraram as maiores taxas de acumulação de nitrogênio e, portanto, a biomassa destas espécies poderia ser utilizada como emenda de tipo orgânico em longo prazo. Já as da anoneira, pelo contrário, acumulou maiores quantidades de carbono do que o resto dos cultivos estudados.