Efecto de sistemas de labranza en luvisoles dedicados a la producción de pastos

Se realizó un experimento con el objetivo de determinar la influencia de los sistemas de labranza en las propiedades de los suelos luvisoles, en el municipio de Las Tunas. Los indicadores evaluados fueron: la densidad aparente (rb), la porosidad total (Pt), la porosidad de aireación (Pa), la materia orgánica (MO) y la densidad y biomasa de oligoquetos. Se muestrearon unidades experimentales, en un diseño de parcelas divididas y tres repeticiones, a las profundidades de 0-5, 5-20 y 20-30 cm. Los contenidos de MO y de densidad y biomasa de oligoquetos se evaluaron hasta los 20 cm. Se consideraron dos sistemas: labranza tradicional (LT) y labranza sin inversión del prisma (LSP) en comparación con un control sin labranza (NL). La LSP produjo la menor densidad y la mayor cantidad de espacios porosos en la matriz del suelo, con valores que difirieron significativamente de la LT y la NL, y favoreció el desarrollo de los oligoquetos hasta la profundidad de 20 cm. El mantenimiento de las capas densas en la profundidad de 20-30 cm en la LT disminuyó la porosidad total y restringió el desarrollo de las raíces, con valores de porosidad de aireación muy por debajo del 10 %. Se concluye que la labranza tradicional afectó el contenido de MO a corto plazo, y mantuvo las capas compactas en el horizonte subyacente, por lo que la continuidad de esta práctica en las áreas ganaderas de la región no se justifica ni a corto ni a largo plazo

Physical characterization of growing media using standard methods (CEN)- Limitations of Applicability for pine bark and vermiculite

CEN standards have helped to harmonize analytical methods for substrate analysis.Though, for special substrates or constituents the applicability might be Iimited. In this paper a comparative study of implementation of CEN standards to samples of pine bark and vermiculite has been carried out. For composted pine bark, an elongation of the equilibrium period up to 72 instead of 48 hours might increase the accuracy of determinations physical parameters according to EN 13041. For vermiculite, we suggest pycnometry as a feasible technique for the determination of particle density (PD), as the determination of organic matter (OM) as requested by EN 13041 for the calculation of the PD seems not to be applicable for this kind of material

Dispersion of metals and arsenic from the tailings of an abandoned mine in Sierra of Madrid

The extraction and processing of minerals produce significant environmental impacts that last long after mining operations have ended. Abandoned mines provide obvious sources of contamination by metals and arsenic in surrounding areas. These areas typically support sparse vegetation, so weather events, typical of Mediterranean environments such as heavy rains, can drag metals and metalloids, in a more or less available form for vegetation, as in solution and suspension to accumulate in lower lands. In this study, the area affected by a copper mine, abandoned early last century in the Sierra de Madrid, was sampled. Soil properties such as pH, EC, total OM and texture were analyzed. Furthermore, the BCR (Bureau Community of Reference) fractionation of metals was carried out in order to evaluate the weathering of the starting materials and the selective movement of different fractions along the slope . Metals and arsenic were detected beyond the mine limits, in areas where water flows in a preferential way. Results showed high concentrations and readily extractable Cu and As, which may suggest potential bioavailability for organisms and may create an environmental risk and potential human exposure what results in a health risk for the population

RGB Vegetation Indices, NDVI, and Biomass as Indicators to Evaluate C-3 and C-4 Turfgrass under Different Water Conditions

[EN] Grasslands have a natural capacity to decrease air pollution and a positive impact on human life. However, their maintenance requires adequate irrigation, which is difficult to apply in many regions where drought and high temperatures are frequent. Therefore, the selection of grass species more tolerant to a lack of irrigation is a fundamental criterion for green space planification. This study compared responses to deficit irrigation of different turfgrass mixtures: a C-4 turfgrass mixture, Cynodon dactylon-Brachypodium distachyon (A), a C-4 turfgrass mixture, Buchloe dactyloides-Brachypodium distachyon (B), and a standard C-3 mixture formed by Lolium perenne-Festuca arundinacea-Poa pratensis (C). Three different irrigation regimes were assayed, full irrigated to 100% (FI-100), deficit irrigated to 75% (DI-75), and deficit irrigated to 50% (DI-50) of container capacity. Biomass, normalized difference vegetation index (NDVI), green area (GA), and greener area (GGA) vegetation indices were measured. Irrigation significantly affected the NDVI, biomass, GA, and GGA. The most severe condition in terms of decreasing biomass and vegetation indices was DI-50. Both mixtures (A) and (B) exhibited higher biomass, NDVI, GA, and GGA than the standard under deficit irrigation. This study highlights the superiority of (A) mixture under deficit irrigation, which showed similar values of biomass and vegetation indices under full irrigated and deficit irrigated (DI-75) container capacities.This research was funded by AREA VERDE-MG projects and Projects GO-PDR18-XEROCESPED funded by the European Agricultural Fund for Rural Development (EAFRD) and IMIDRA.Marín, J.; Yousfi, S.; Mauri, PV.; Parra, L.; Lloret, J.; Masaguer, A. (2020). RGB Vegetation Indices, NDVI, and Biomass as Indicators to Evaluate C-3 and C-4 Turfgrass under Different Water Conditions. Sustainability. 12(6):1-16. https://doi.org/10.3390/su1206216011612

Effect of magnetite nanoparticles on heavy metals behavior in contaminated soils

The extraction and processing of minerals produce significant environmental impacts that last long after mining operations have ended. Abandoned mines provide obvious sources of contamination by metals and arsenic in surrounding areas. These areas typically support sparse vegetation, so weather events, typical of Mediterranean environments such as heavy rains, can drag metals and metalloids, in a more or less available form for vegetation, as in solution and suspension to accumulate in lower lands. In this study, the area affected by a copper mine, abandoned early last century in the Sierra de Madrid, was sampled. Soil properties such as pH, EC, total OM and texture were analyzed. Furthermore, the BCR (Bureau Community of Reference) fractionation of metals was carried out in order to evaluate the weathering of the starting materials and the selective movement of different fractions along the slope . Metals and arsenic were detected beyond the mine limits, in areas where water flows in a preferential way. Results showed high concentrations and readily extractable Cu and As, which may suggest potential bioavailability for organisms and may create an environmental risk and potential human exposure what results in a health risk for the population

Phytoextraction of heavy metals from mine soils using hyperaccumulator plants.

Phytoextraction is an environmental-friendly and cost-effective technology that uses metal hyperaccumulator plants to remove heavy metals from soils. The metals are absorbed by the roots, transported and accumulated in the aerial parts of the plants, which can be harvested and eliminated. The aim of this work was to study some hyperaccumulator species that could be useful to decontaminate mine soils and also to investigate the bioavailability and uptake of these metals by plants with the addition of organic amendments. Pot experiments were performed with soil samples collected from two mining areas in the north of Madrid, where there was an intense mining activity more than 50 years ago. Three species (Thlaspi arvense, Brassica juncea and Atriplex halimus) were grown under controlled conditions in pots filled with contaminated soils mixed with 0 Mg, 30 Mg and 60 Mg per hectare of two different organic amendments: a commercial compost made of pine bark, peat and wood fiber and other made of horse and sheep manure and wood fiber. Plants were harvested at the end of their crop cycle and were digested in order to measure metal concentration (Zn, Cu and Cd) in roots and shoots. Highest plant metal concentration was observed in pots treated with pine bark amendment and with pure soil due to an increase in metal bioavailability with decreasing pH. Also in those treatments the total plant biomass was lower, even some plants could not germinate. On the contrary, there was a lower metal concentration in plant tissues of pots with manure because its higher pH whereas plant growth was significantly larger so there was an incresing amount of metals removed from soil by plants. Comparing the three species results indicate a higher total metal uptake in A. halimus than B. juncea and T. arvense. In conclusion, results show that pH affects metal bioavailability and uptake by hyperaccumulator plants. Addition of organic amendments could be a successful technique for stabilization of metals in contaminated soils

Diversidad bacteriana en suelos de zonas contaminadas y no contaminadas de una mina de cobre = Bacterial diversity in soils from contaminated and uncontaminated areas of a copper mine

Para entender la dinámica ecológica del suelo es de primordial importancia realizar un esquema de la distribución filogenética de las distintas bacterias que viven en él. Los análisis moleculares, en especial el metagenómico, puede aportar información detallada sobre la diversidad, estructura y funcionamiento de los microorganismos presentes en un suelo, información que pueden servir como base para su manejo y recuperación. El objetivo de este estudio fue evaluar la diversidad de las comunidades bacterianas en dos zonas de un suelo minero ubicado en la comunidad de Madrid. Los muestreos se realizaron en dos zonas de la mina identificadas como zona 1 (suelo no afectado) y zona 3 (zona de escombrera). Se realizaron análisis metagenómicos de las comunidades bacterianas presentes, con muestras de ambas zonas. Del total de secuencias bacterianas evaluadas, sólo el 1% mostró coincidencias en las bases de datos del Centro Nacional para la Información Biotecnológica (NCBI). Los resultados mostraron que el número de secuencias del dominio Bacteria es mayor en la zona 1 que en la zona 3. Aunque no se encontraron diferencias significativas entre los diferentes filos de bacterias por zona, sí se observaron diferencias en cuanto al número de especies dentro de los diferentes filos y entre las zonas de muestreo

Desafíos en el desarrollo de sustratos para plántulas de espárrago (Asparagus officinalis L.)

El espárrago (Asparagus officinalis L.) es una planta que se cultiva tradicionalmente, siendo considerada en ciertos periodos, como un cultivo con alto retorno económico. Sin embargo, los costes de producción han ido aumentando. Un problema muy común en los semilleros de espárrago es la fragilidad del cepellón. Además, en el momento de trasplante de plántulas de espárrago, sus raíces no se encuentran totalmente desarrolladas y, por ello, se rompen fácilmente. El objetivo general de este trabajo es verificar los desafíos en el desarrollo de nuevos sustratos para el cultivo del espárrago. Para ello, se han realizado ensayos preliminares en laboratorio con productos comerciales aglomerantes que no dañan el medio ambiente, con el objetivo de mejorar las características de resistencia del cepellón. Los resultados muestran que hay un cambio en la compactación del cepellón. Complementariamente, se busca el desarrollo de un método objetivo para la determinación de las características mecánicas del sustrato, para que sea posible la comparación de los tratamiento

Effects of soluble humic acids on the uptake of heavy metals by Vetiveria zizanioides (L.) Nash in contaminated mining soils

In the past, mining wastes were left wherever they might lie in the surroundings of the mine area. Unfortunately, inactive and abandoned mines continue to pollute our environment, reason why these sites should be restored with minimum impact. Phytoextraction is an environmental-friendly and cost-effective technology less harmful than traditional methods that uses metal hyperaccumulator or at least tolerant plants to extract heavy metals from polluted soils. One disadvantage of hyperaccumulator species is their slow growth rate and low biomass production. Vetiveria zizanioides (L.) Nash, perennial species adapted to Mediterranean climate has a strong root system which can reach up to 3 m deep, is fast growing, and can survive in sites with high metal levels (Chen et al., 2004). Due to the fact that metals in abandoned mine tailings become strongly bonded to soil solids, humic acids used as chelating agents could increase metal bioavailability (Evangelou et al., 2004; Wilde et al., 2005) and thereby promote higher accumulation in the harvestable parts of the plant. The objective of this study was to examine the performance of humic acid assisted phytoextraction using Vetiveria zizanioides (L.) Nash in heavy metals contaminated soils

Use of leonardite humic acids for metals extraction in mine soils

Mine soils usually exhibit high levels of metal contamination. Phytoextraction is an environmental friendly and cost-effective technique for soil remediation, which consists of removal of metals from soil by plant roots and their translocation to aerial parts. Humic substances used as soil amendments could enhance metal mobility and uptake by plants due to formation of soluble complexes. This study aimed to evaluate the effects of a commercial humic acid derived from leonardite added at different rates and pH to a contaminated soil from an abandoned copper mine in Colmenarejo (Madrid, Spain) on metal mobility. The objective was to assess its potential as soil amendment for phytoextraction. Soil samples (10 g) were sequentially extracted 6 times with 20 mL of solution containing humic acid at: 0 (control), 0.25, 1, and 5 g L-1. Solutions were previously adjusted to pH: 4, 6.1 (natural soil pH) and 8. Extracts were analyzed for pH, electrical conductivity, metal concentrations (Cu and Zn) and ratio of absorption at 465 to 665 nm (E4/E6) as an indirect measure of soluble organic matter content. Results showed that addition of higher doses of humic acid increased soluble organic matter content, and therefore extracted a higher concentration of Zn and particularly Cu, due to formation of soluble humic complexes. At higher pH humic acid became more soluble and managed to extract increasing amounts of metals, except in the highest humic acid treatment due to its precipitation or flocculation. The use of this humic acid as soil amendment could promote metal phytoextraction by tolerant plants in contaminated mine soils, but it should be applied at proper pH and other soil conditions to avoid risk of metal leaching to groundwate