Effects of sheep and horse manure and pine bark amendments on metal distribution and chemical properties of contaminated mine soils.

Mine soils usually contain large levels of heavy metals and poor fertility conditions which limit their reclamation and the application of phyto-remediation technologies. Two organic waste materials (pine bark compost and sheep and horse manure compost), with different pHs and varying degrees of humification and nutrient contents, were applied as amendments to assess their effects on copper (Cu) and zinc (Zn) bioavailability and on fertility conditions of mine soils. Soil samples collected from two abandoned mining areas near Madrid (Spain) were mixed with 0, 30 and 60 t ha?1 of the organic amendments. The concentrations of metals among the different mineral and organic fractions of soil were determined by several extraction procedures to study the metal distribution in the solid phase of the soil affected by the organic amendments. The results showed that the manure amendment increased the soil pH and the cation exchange capacity and enhanced the nutrient levels of these soils. The pine bark amendment decreased the soil pH and did not significantly change the nutrient status of soil. Soil pH, organic matter content and its degree of humification, which were altered by the amendments, were the main factors affecting Cu fractionation. Zn fractionation was mainly affected by soil pH. The addition of manure not only improved soil fertility, but also decreased metal bioavailability resulting in a reduction of metal toxicity. Conversely, pine bark amendment increased metal ioavailability. The use of sheep and horse manure could be a cost-effective practice for the restoration of contaminated mine soils.

¿Planificar los comunes? Autogestión, regulación comunal del suelo y su eclipse en la Inglaterra precapitalista.

El progresivo adelgazamiento del Estado del Bienestar y la privatización de bienes y servicios públicos han propiciado la aparición de discursos que reclaman la recuperación de los comunes y su autogestión colectiva. En ese contexto las tierras y derechos comunales de la Inglaterra pre-capitalista han dejado de ser un asunto académico, reapareciendo intensamente en los imaginarios socioespaciales del activismo global. Aunque esa reapropiación del pasado parece legítima, dichas narrativas ignoran a menudo la complejidad implícita en la gestión, planificación y evolución de los comunes históricos. Para subsanar estas lagunas estudiamos las instituciones y modos de gobierno que sustentaban el régimen comunal de la tierra en este período, enfatizando su condición de planificación autogestionada de los usos del suelo y las prácticas asociadas al mismo. Este régimen fue sustituido por las leyes de cercamiento, dando paso a una lógica de planificación centralizada e insolidaria: una lógica en la que estaba implícita no sólo la extinción del control comunal y la privatización de la tierra, sino también la desposesión de los trabajadores rurales y su progresiva proletarización. Palabras clave: comunes, derecho comunal, planificación socioespacial, leyes de cercamiento, autogestión. ....................................................... The ongoing eclipse of the Welfare State and the privatisation of public goods and services have triggered the appearance of discourses that claim the recovery of the commons and their collective self-management. In this context historical common lands and rights in pre-capitalist England are no longer a mere academic issue, as they reappear intensely in the sociospatial imaginaries of global activism. This reappropriation of the past seems legitimate, but such narratives often ignore the complexity of the management, planning and evolution of the historical commons. To fill these lacunae I study the institutions and modes of government that underpinned the communal regime in this period, emphasizing its condition of self-managed land use planning. Enclosure acts destroyed this regime, introducing a new logic of centralized, iniquitous planning: a logic which included not only the extinction of communal institutions and privatisation of land, but also the dispossession of rural labourers and their progressive proletarianisation.