Evolución de la aptitud para el riego de los suelos de La Pedrera (provincia de Alicante)

[ES] Existen necesidades tan fundamentales como la necesidad de producir alimentos, necesidad de un lugar en donde vivir, etc., pero también la necesidad de la preservación del medio natural, debido a que los recursos podrían dejar de ser renovables si no son utilizados de manera razonable y equilibrada, atentando contra el desarrollo sostenible; sin embargo, a pesar de la importancia para la vida, tanto el suelo como los recursos hídricos no han recibido de la sociedad la atención que merecen. Su degradación es una seria amenaza para el futuro de la humanidad, los cuales podrían estar destinados a ser el principal problema para el presente siglo. Por esta razón, el presente trabajo de investigación está orientado a realizar un análisis riguroso de la evolución de la aptitud para el riego de los suelos de la Pedrera, situado en una zona semiárida al sur de la provincia de Alicante (España), tomando como referencia o punto de partida diversas evaluaciones de los suelos de la comarca iniciadas en 1974, año en donde se recomendó poner en desarrollo alrededor de 7.500 hectáreas en respuesta a la calidad y disponibilidad de agua para riego procedente del trasvase del Tajo. Sin embargo, en el estudio del año 1997 se evidenció que la calidad de los suelos había sido afectada por importantes procesos de degradación como la salinidad y la sodicidad, producto de haber recurrido a fuentes de agua para riego con alto contenido en sales y por ende de baja calidad, para poder suplir la nueva superficie de regadío que pasó a ser de 13.000 has. Por éste motivo se recomendó utilizar recursos con menor conductividad eléctrica, utilizándose aguas procedentes en su mayoría de las estaciones depuradoras de aguas residuales (EDARS). Ya en el año 2007, en una nueva evaluación de la calidad de los suelos se comprobó que la sodicidad se había reducido en un 28% respecto a los resultados de 1997. No obstante, el estudio reveló que el 21.5% de las muestras deterioró su calidad, el 64.3% logro conservarla y el 14.5% mejoró, evidenciando así mismo que el principal factor limitante para el uso de los suelos era la salinidad seguido del porcentaje de caliza. El presente trabajo contempla realizar una nueva evaluación para identificar si la aptitud para el riego de los suelos ha mejorado o ha sufrido deterioro. Para ello se ha planteado el muestreo y análisis de 144 horizontes de suelos procedentes de 28 calicatas realizadas en las mismas zonas de control, aplicando la misma metodología utilizada desde el año 1974: evaluación mediante el sistema de clasificación de tierras según su aptitud para riego (USBR) y el análisis de diversos parámetros edáficos como textura, conductividad eléctrica del extracto, pH, cationes, aniones, contenido de materia orgánica, carbonatos y bicarbonatos, etc.[EN] There are such fundamental needs as the need to produce food, the need for a place to live, etc., but also the need for the preservation of the natural environment, because the resources could no longer be renewable if they are not used in a reasonable manner and balanced, undermining sustainable development; However, despite the importance for life, both soil and water resources have not received from society the attention they deserve. Its degradation is a serious threat to the future of humanity, which could be destined to be the main problem for the present century. For this reason, the present research pretend to carry out a rigorous analysis of the evolution of irrigation aptitudes of Pedrera¿s area. It is located in a semi-arid zone to the south of the province of Alicante (Spain), taking as reference or point of Various land evaluations started in 1974, year in which it was recommended to put into development around 7,500 hectares in response to the quality and availability of irrigation water from Tajo¿s transfer. However, the results of the year 1997 showed that the quality of the soils had been affected by important degradation processes such as salinity and sodicity, as a result of having used water sources for irrigation with high salt content and therefore of low quality, to be able to replace the new irrigated area that went from being 7,500 hectares to 13,000 hectares. For this reason, it was recommended to use resources with lower electrical conductivity, applying water mostly from wastewater treatment plants (EDARS). Already in 2007, in a new evaluation of the quality of soils of La Pedrera, it was found that sodicity had been reduced by 28% compared to the 1997 results, however, this research revealed that 21.5% of samples deteriorated its quality, 64.3% managed to preserve it and 14.5% improved, also showing that the main limiting factor for the use of soils was salinity followed by the percentage of limestone. A new evaluation is currently being carried out to identify whether the suitability for soil irrigation has improved or suffered deterioration. For this, it has been proposed to perform the sampling and analysis of 144 soil horizons from 28 soil pits, carried out in the same control areas and with the same methodology used since 1974, also using the land classification system according to their ability to irrigation (USBR), and various edaphic parameters for its determination, such as texture, electrical conductivity of the extract, pH, cations, anions, organic matter content, carbonates and bicarbonates, etc.Zuzunaga Rosas, JG. (2019). Evolución de la aptitud para el riego de los suelos de La Pedrera (provincia de Alicante). http://hdl.handle.net/10251/129486TFG

Mitigation of salt stress in lettuce by a biostimulant that protects the root absorption zone and improves biochemical responses

Horticultural crops constantly face abiotic stress factors such as salinity, which have intensified in recent years due to accelerated climate change, significantly affecting their yields and profitability. Under these conditions, it has become necessary to implement effective and sustainable solutions to guarantee agricultural productivity and food security. The influence of BALOX®, a biostimulant of plant origin, was tested on the responses to salinity of Lactuca sativa L. var. longifolia plants exposed to salt concentrations up to 150 mM NaCl, evaluating different biometric and biochemical properties after 25 days of treatment. Control plants were cultivated under the same conditions but without the biostimulant treatment. An in situ analysis of root characteristics using a non-destructive, real-time method was also performed. The salt stress treatments inhibited plant growth, reduced chlorophyll and carotenoid contents, and increased the concentrations of Na+ and Cl- in roots and leaves while reducing those of Ca2+. BALOX® application had a positive effect because it stimulated plant growth and the level of Ca2+ and photosynthetic pigments. In addition, it reduced the content of Na+ and Cl- in the presence and the absence of salt. The biostimulant also reduced the salt-induced accumulation of stress biomarkers, such as proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2). Therefore, BALOX® appears to significantly reduce osmotic, ionic and oxidative stress levels in salt-treated plants. Furthermore, the analysis of the salt treatments’ and the biostimulant’s direct effects on roots indicated that BALOX®’s primary mechanism of action probably involves improving plant nutrition, even under severe salt stress conditions, by protecting and stimulating the root absorption zone

Effect of a Biostimulant Based on Polyphenols and Glycine Betaine on Tomato Plants¿ Responses to Salt Stress

[EN] Climate change accentuates abiotic stress conditions putting at risk several commercial cultivars particularly vulnerable to salinity in the early stages of development, which makes adopting new technologies in tune with the environment necessary to mitigate its impact. In this study, we tested the possible effects of a commercial biostimulant (BALOX®) on enhancing salt stress tolerance in salt-treated tomato plants, analysing plant growth and several stress biochemical markers: photosynthetic pigments, ion contents in roots and leaves, leaf concentrations of different osmolytes, oxidative stress markers, non-enzymatic antioxidants, and the specific activities of major antioxidant enzymes. The experimental design consisted of three soil salinity levels (non-saline, saline, and very saline), two biostimulant doses (0.4 mL and 0.8 mL of the BALOX® stock per litre of irrigation water), and the non-treated control (without biostimulant), evaluated at 30 and 60 days of treatment. The biostimulant favoured plant growth, especially at the root level and in saline soils. In addition, it helped reduce Na+ and Cl uptake by the roots and seemed to stimulate, to some extent, K+ and Ca2+ transport to the aerial part of the plant. The BALOX® application significantly reduced the level of stress affecting the plants in saline soils, as shown by the decrease in the contents of proline and oxidative stress biomarkers and the activity of salt-induced antioxidant enzymes. Some of the biostimulant effects were also observed under low salinity conditions; therefore, in addition to enhancing salt stress responses, BALOX® appears to stimulate the growth of tomato plants through a general improvement of photosynthesis and primary metabolism.This research was partly funded by the company Innovak Global and partly by UPV through internal funds to S.I.-A., M.B. and O.V.Zuzunaga-Rosas, J.; González-Orenga, S.; Tofei, AM.; Boscaiu, M.; Moreno-Ramón, H.; Ibañez Asensio, S.; Vicente, O. (2022). Effect of a Biostimulant Based on Polyphenols and Glycine Betaine on Tomato Plants¿ Responses to Salt Stress. Agronomy. 12(9):1-26. https://doi.org/10.3390/agronomy1209214212612

Use of a Biostimulant to Mitigate the Effects of Excess Salinity in Soil and Irrigation Water in Tomato Plants

Global warming is linked to progressive soil salinisation, which reduces crop yields, especially in irrigated farmland on arid and semiarid regions. Therefore, it is necessary to apply sustainable and effective solutions that contribute to enhanced crop salt tolerance. In the present study, we tested the effects of a commercial biostimulant (BALOX®) containing glycine betaine (GB) and polyphenols on the activation of salinity defense mechanisms in tomato. The evaluation of different biometric parameters and the quantification of biochemical markers related to particular stress responses (osmolytes, cations, anions, oxidative stress indicators, and antioxidant enzymes and compounds) was carried out at two phenological stages (vegetative growth and the beginning of reproductive development) and under different salinity conditions (saline and non-saline soil, and irrigation water), using two formulations (different GB concentrations) and two doses of the biostimulant. Once the experiments were completed, the statistical analysis revealed that both formulations and doses of the biostimulant produced very similar effects. The application of BALOX® improved plant growth and photosynthesis and assisted osmotic adjustment in root and leaf cells. The biostimulant effects are mediated by the control of ion transport, reducing the uptake of toxic Na+ and Cl− ions and favoring the accumulation of beneficial K+ and Ca2+ cations, and a significant increase in leaf sugar and GB contents. BALOX® significantly reduced salt-induced oxidative stress and its harmful effects, as evidenced by a decrease in the concentration of oxidative stress biomarkers, such as malondialdehyde and oxygen peroxide, which was accompanied by the reduction of proline and antioxidant compound contents and the specific activity of antioxidant enzymes with respect to the non-treated plants

Mitigation of salt stress in lettuce by a biostimulant that protects the root absorption zone and improves biochemical responses

[EN] Horticultural crops constantly face abiotic stress factors such as salinity, which have intensified in recent years due to accelerated climate change, significantly affecting their yields and profitability. Under these conditions, it has become necessary to implement effective and sustainable solutions to guarantee agricultural productivity and food security. The influence of BALOX®, a biostimulant of plant origin, was tested on the responses to salinity of Lactuca sativa L. var. longifolia plants exposed to salt concentrations up to 150 mM NaCl, evaluating different biometric and biochemical properties after 25 days of treatment. Control plants were cultivated under the same conditions but without the biostimulant treatment. An in situ analysis of root characteristics using a non-destructive, real-time method was also performed. The salt stress treatments inhibited plant growth, reduced chlorophyll and carotenoid contents, and increased the concentrations of Na+ and Cl- in roots and leaves while reducing those of Ca2+. BALOX® application had a positive effect because it stimulated plant growth and the level of Ca2+ and photosynthetic pigments. In addition, it reduced the content of Na+ and Cl- in the presence and the absence of salt. The biostimulant also reduced the salt-induced accumulation of stress biomarkers, such as proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2). Therefore, BALOX® appears to significantly reduce osmotic, ionic and oxidative stress levels in salt-treated plants. Furthermore, the analysis of the salt treatments¿ and the biostimulant¿s direct effects on roots indicated that BALOX®¿s primary mechanism of action probably involves improving plant nutrition, even under severe salt stress conditions, by protecting and stimulating the rootabsorption zone.Zuzunaga-Rosas, J.; Calone, R.; Mircea, DM.; Shakya, R.; Ibañez Asensio, S.; Boscaiu, M.; Fita, A.... (2024). Mitigation of salt stress in lettuce by a biostimulant that protects the root absorption zone and improves biochemical responses. Frontiers in Plant Science. 15. https://doi.org/10.3389/fpls.2024.13417141

Effect of Recurrent Salt and Drought Stress Treatments on the Endangered Halophyte <i>Limonium angustebracteatum</i> Erben

Limonium angustebracteatum is an endemic halophyte from the Spanish Mediterranean coastal salt marshes. To investigate this species’ ability to cope with recurrent drought and salt stress, one-year-old plants were subjected to two salt stress treatments (watering with 0.5 and 1 M NaCl solutions), one water stress treatment (complete irrigation withholding), or watered with non-saline water for the control, across three phases: first stress (30 days), recovery from both stresses (15 days), and second stress (15 days). Growth and biochemical parameters were determined after each period. The plants showed high salt tolerance but were sensitive to water deficit, as shown by the decrease in leaf fresh weight and water content, root water content, and photosynthetic pigments levels in response to the first water stress; then, they were restored to the respective control values upon recovery. Salt tolerance was partly based on the accumulation of Na+, Cl− and Ca2+ in the roots and predominantly in the leaves; ion levels also decreased to control values during recovery. Organic osmolytes (proline and total soluble sugars), oxidative stress markers (malondialdehyde and H2O2), and antioxidant compounds (total phenolic compounds and flavonoids) increased by various degrees under the first salt and water stress treatments, and declined after recovery. The analysed variables increased again, but generally to a lesser extent, during the second stress phase, suggesting the occurrence of stress acclimation acquired by the activation of defence mechanisms during the first stress period

Effect of a Biostimulant Based on Polyphenols and Glycine Betaine on Tomato Plants&rsquo; Responses to Salt Stress

Climate change accentuates abiotic stress conditions putting at risk several commercial cultivars particularly vulnerable to salinity in the early stages of development, which makes adopting new technologies in tune with the environment necessary to mitigate its impact. In this study, we tested the possible effects of a commercial biostimulant (BALOX&reg;) on enhancing salt stress tolerance in salt-treated tomato plants, analysing plant growth and several stress biochemical markers: photosynthetic pigments, ion contents in roots and leaves, leaf concentrations of different osmolytes, oxidative stress markers, non-enzymatic antioxidants, and the specific activities of major antioxidant enzymes. The experimental design consisted of three soil salinity levels (non-saline, saline, and very saline), two biostimulant doses (0.4 mL and 0.8 mL of the BALOX&reg; stock per litre of irrigation water), and the non-treated control (without biostimulant), evaluated at 30 and 60 days of treatment. The biostimulant favoured plant growth, especially at the root level and in saline soils. In addition, it helped reduce Na+ and Cl&minus; uptake by the roots and seemed to stimulate, to some extent, K+ and Ca2+ transport to the aerial part of the plant. The BALOX&reg; application significantly reduced the level of stress affecting the plants in saline soils, as shown by the decrease in the contents of proline and oxidative stress biomarkers and the activity of salt-induced antioxidant enzymes. Some of the biostimulant effects were also observed under low salinity conditions; therefore, in addition to enhancing salt stress responses, BALOX&reg; appears to stimulate the growth of tomato plants through a general improvement of photosynthesis and primary metabolism

Evaluation of Drought Responses in Two <i>Tropaeolum</i> Species Used in Landscaping through Morphological and Biochemical Markers

One of the most important challenges horticultural crops confront is drought, particularly in regions such as the Mediterranean basin, where water supplies are usually limited and will become even scarcer due to global warming. Therefore, the selection and diversification of stress-tolerant cultivars are becoming priorities of contemporary ornamental horticulture. This study explored the impact of water stress on two Tropaeolum species frequently used in landscaping. Young plants obtained by seed germination were exposed to moderate water stress (half the water used in the control treatments) and severe water stress (complete withholding of irrigation) for 30 days. Plant responses to these stress treatments were evaluated by determining several growth parameters and biochemical stress markers. The latter were analysed by spectrophotometric methods and, in some cases, by non-destructive measurements using an optical sensor. The statistical analysis of the results indicated that although the stress responses were similar in these two closely related species, T. minus performed better under control and intermediate water stress conditions but was more susceptible to severe water stress. On the other hand, T. majus had a stronger potential for adaptation to soil water scarcity, which may be associated with its reported expansion and naturalisation in different regions of the world. The variations in proline and malondialdehyde concentrations were the most reliable biochemical indicators of water stress effects. The present study also showed a close relationship between the patterns of variation of flavonoid and chlorophyll contents obtained by sensor-based and spectrophotometric methods