The European Union requires member states to estimate their wine growing potential. For this purpose, most member states have developed or updated vineyard registers. The present study suggests locating vineyards using medium spatial resolution satellite imagery. The work was carried out using Landsat images that were validated for the Designation of Origin "Bierzo", León, Spain. The methodology described in this paper yields a producer's accuracy of 0.88 and a user's accuracy of 0.63. The vineyard areas for each municipality were estimated from the classified images by linear regression, with fits of R2 > 0.80. The method gives good results at the municipal scale. ; La Unión Europea requiere que sus estados miembros determinen su potencial de producción de vino. Para realizar esta tarea la mayoría de los estados miembros han desarrollado o actualizado registros vinícolas. El presente estudio propone localizar viñedos utilizando imágenes de satélite de resolución espacial media. El trabajo se desarrolló utilizando imágenes Landsat que se validaron para la Denominación de Origen "Bierzo", León, España. La metodología descrita en el artículo logró una exactitud del productor de 0,88 y una exactitud para el usuario de 0,63. La superficie de viñedo para cada municipio fue estimada a partir de imágenes clasificadas, mediante regresión lineal, obteniendo valores de R2 superiores a 0,80. El método aporta buenos resultados a escala municipal.
Cassava (Manihot esculenta Crantz.) in Indonesia can be considered as a controversial crop. This crop has a tremendous yield potential of almost 100 t of fresh roots/ha, but official data show that its actual productivity is only 10-20% of its biological potential. It is considered to have multiple end uses, such as food, feed, raw material for industry and export. Very often, however, cassava farmers complain about the low and unstable price they receive for their product. A longer list can be developed concerning the contradictory nature of cassava. This in turn should be perceived as a special challenge to those who are more concerned about the improvement of people's living standards rather than the crop itself. Starting from 1973, the cassava production system in Indonesia has shown a declining annual growth rate for the harvested area (-0.41%), but an increasing rate for both production (1.53%) and yield (1.93%). Since the standard deviation of the rate is much greater than its average, values of the rate and its sign (positive and negative) should be considered as a trend indicator only, and they can not be used for prediction purposes. At present, cassava in Indonesia is harvested from around 1.2 million ha, producing around 15-17 million tonnes of fresh roots, as the yield is only about 12-13 t/ha. Most cassava is produced by small farmers that are weak in resources endowment, either in economic or social terms. Little purchased inputs, especially chemical or inorganic fertilizers, are applied, and as a result cassava production is frequently blamed as the cause of soil degradation. The crop is mostly grown in upland areas with undulating topography. Since its planting time should be compatible with the distribution of rainfall, the flexibility in planting and harvesting time is limited. As a consequence, the existence of a peak in planting and harvesting time is difficult to avoid. Abundance of cassava roots during the peak harvesting time results in low prices. From an individual farmer's point of view, his income is determined by his productivity level. Logically, any improvement in productivity should increase farmer's income. However, this rarely happens, because the price is governed by the total amount of roots produced. As price fluctuation is the result of supply and demand imbalance, any decrease in price can be perceived as an indicator of limited demand. There is a belief that cassava farmers, especially the low-income groups, are trapped in a vicious cycle: changes in yield-planted area-production, are countered by changes in prices which go up and down. This condition in turn prevents farmers from improving their income. If the opinion that demand is the most important limiting factor for production growth is true, the best solution should be a demand-led strategy. Demand for cassava in Indonesia is mainly in the areas of food, industry (mainly processing of starch and starch-based products), export and feed. Future prospects for using cassava as food will depend mainly on: (1) rice availability, since rice is the most preferred staple food for Indonesian people; and (2) cassava product development activities, as the social bias against cassava as being a food for the poor is strong and real. The existence of starch processing and starch-based industries, especially on a large scale, have been present for some time, but their role in improving farmers' welfare should be questioned. The growth in cassava exports will face two barriers: first, strong competition from Thailand, and secondly, the domestic price. Demand for cassava as a raw material for production of feed will depend on its price in relation to that of maize. It can be concluded that from the grower's view point cassava is a cash crop rather than a subsistence crop, and therefore the crop is a source of income rather than a source of food. As a consequence, every effort to improve the crop's performance should strife to ensure an increase in the grower's welfare. In addition, there has to be a significant increase in net income for individual farmers, due to a correct balance between production and demand. In fact, economic and social issues are the principal constraints. Unfortunately, these two issues are beyond the farmer's control. Concerted efforts among farmers, government and non-government organizations, research and development agencies, and others are urgently needed. While technical expertise should continuously be improved, much is known already to help increase the present productivity level towards its full yield potential.
Klappentext: La verdad es una suma de I like, y la falsedad su ausencia: he aquí el ecosistema donde prospera la postverdad, así como un despreocupado nihilismo que tiene consecuencias políticas inmensas. La realidad es lo que fluye tras la pantalla. Nada escapa a esa condición de superficie profunda, expresión a medio camino entre el oxímoron y el vértigo. Tras la pantalla están las emociones, las relaciones sociales, los recuerdos, nuestros vínculos con las personas y las instituciones. En su superficie transita la vida y la nada. La pantalla digitalizada ya no es un reflejo ni tampoco un destello. Se ha convertido en una superficie porosa que no sirve para comunicar, sino solo para negociar entre emisores y receptores qué es real y qué no, qué es bello o feo, justo o injusto. El hombre postmoderno ha acabado dando la razón al hombre medieval: en efecto, el mundo es plano.
