Arbuscular mycorrhizal fungi in soil aggregates from fields of "murundus" converted to agriculture

The objective of this work was to evaluate the spore density and diversity of arbuscular mycorrhizal fungi (AMF) in soil aggregates from fields of "murundus" (large mounds of soil) in areas converted and not converted to agriculture. The experiment was conducted in a completely randomized design with five replicates, in a 5x3 factorial arrangement: five areas and three aggregate classes (macro-, meso-, and microaggregates). The evaluated variables were: spore density and diversity of AMF, total glomalin, total organic carbon (TOC), total extraradical mycelium (TEM), and geometric mean diameter (GMD) of soil aggregates. A total of 21 AMF species was identified. Spore density varied from 29 to 606 spores per 50 mL of soil and was higher in microaggregates and in the area with 6 years of conversion to agriculture. Total glomalin was higher between murundus in all studied aggregate classes. The area with 6 years showed lower concentration of TOC in macroaggregates (8.6 g kg-1) and in microaggregates (10.1 g kg-1). TEM was greater at the top of the murundus in all aggregate classes. GMD increased with the conversion time to agriculture. The density and diversity of arbuscular mycorrhizal spores change with the conversion of fields of murundus into agriculture.

Les Comptes régionaux de l'agriculture : de 1962 à 1967 / Institut national de la statistique et des études économiques ; [rédigé] par Jean Ousset

Collection : Les Collections de l'Insee ; 104, 13

Dictionnaire universel d'agriculture et de jardinage, de fauconnerie, chasse, pêche, cuisine et manège.... Tome 2

Collection : Archives de la linguistique française ; 17

Dictionnaire universel d'agriculture et de jardinage, de fauconnerie, chasse, pêche, cuisine et manège.... Tome 1

Collection : Archives de la linguistique française ; 17

Background, current status and future prospects of transgenic crop plant development

Les plantes transgèniques són una part integral de l’agricultura contemporània. Durant l’any 2006 més de noranta milions d’hectàrees de plantes transgèniques van ser cultivades en vint-i-un països. Des de la comercialització de la primera planta transgènica el 1996 els nivells d’adopció d’aquests cultius han augmentat anualment amb percentatges de dos dígits. El desenvolupament i la comercialització de les plantes transgèniques van lligats estretament al comerç mundial, a la globalització, a la disponibilitat de suficient menjar, a la protecció del medi ambient i del consumidor i a la propietat intel·lectual. En aquest article exposem els avenços més recents i les tendències actuals en el desenvolupament dels cultius transgènics i de la seva utilització. També ens fem ressò d’alguns assumptes no científics que s’han de solucionar abans que aquests cultius arribin al màxim del seu potencial, proporcionant una agricultura més sostenible i ecològica. Finalment, ressaltarem la importància de com les plantes transgèniques poden contribuir en la disponibilitat de menjar i en la millora de la pobresa en els països en vies de desenvolupament.

The role of community and population ecology in applying mycorrhizal fungi for improved food security.

The global human population is expected to reach ∼9 billion by 2050. Feeding this many people represents a major challenge requiring global crop yield increases of up to 100%. Microbial symbionts of plants such as arbuscular mycorrhizal fungi (AMF) represent a huge, but unrealized resource for improving yields of globally important crops, especially in the tropics. We argue that the application of AMF in agriculture is too simplistic and ignores basic ecological principals. To achieve this challenge, a community and population ecology approach can contribute greatly. First, ecologists could significantly improve our understanding of the determinants of the survival of introduced AMF, the role of adaptability and intraspecific diversity of AMF and whether inoculation has a direct or indirect effect on plant production. Second, we call for extensive metagenomics as well as population genomics studies that are crucial to assess the environmental impact that introduction of non-local AMF may have on native AMF communities and populations. Finally, we plead for an ecologically sound use of AMF in efforts to increase food security at a global scale in a sustainable manner.

The economic relevance of climate variables in agriculture: the case of Spain

We estimate how climate variables affect price and acreage of productive farmland using the Ricardian approach. Furthermore, we use our estimations to evaluate the joint effects of possible cli- mate changes within the time horizon of 2010 and 2050. Our results show that the price of rainfed land in Spain tends to increase but rainfed acreage decreases. On the other hand, the effect on irrigated farmland price and acreage presents some mixed results, however, in the long run the dominant pattern is clearly increasing for both prices and acreage.

The economic relevance of climate variables in agriculture: The case of Spain

We estimate the impact of the different climate variables on the value of Spanish farmland. We distinguish between irrigated and non-irrigated lands and use data on temperature, precipitations, physical and socioeconomic characteristics to measure these effects on farm prices and in the number of hectares of farmland. We conclude presenting the main results of our analysis, region by region, and examining the policies that could be more effective to prevent undesired effects.

The resource-based view of the firm - resources, capabilities and sustainable competitive advantage

The main objective of this research paper was to synthesize, integrate and analyze the theoretical foundation of the resource-based view of the firm on sustainable competitive advantage. Accordingly, this research was a literature research employing the methodology of interpretative study of concept and unobtrusive measures. The core and majority of the research data was gathered from the major online journal databases. Only peer-reviewed articles from highly-esteemed journals on the subject of competitive advantage were used. The theoretical core of the research paper was centred on resources, capabilities, and the sustainability dilemma of competitive advantage. Furthermore, other strategic management concepts relating to the resource-based view of the firm were used with reference to the research objectives. The resource-based view of the firm continues to be a controversial but important are of strategic management research on sustainable competitive advantage. Consequently, the theoretical foundation and the empirical testing of the framework needs further work. However, it is evident that internal organizational factors in the form of resources and capabilities are vital for the formation of sustainable competitive advantage. Resources and capabilities are not, however, valuable on their own - competitive advantage requires seamless interplay and complementarity between bundles of resources and capabilities.