Términos relacionados

11 resultados encontrados para: AUTOR: Janssens, Marc J. J.
  • «
  • 1 de 2
  • »
1.
Artículo
PDF PDF
Resumen en: Español |
Resumen en español

La situación en la fruticultura orgánica de Mesoamérica no es fácil a cualificar y cuantificar. Indudablemente existen áreas certificadas sin embargo faltan datos exactos. En otra manera muchos campesinos cultivan frutas y vegetales sin el uso de fertilizantes inorgánicos y sin aplicaciones de pesticidas por falta de insumos propios. Este estudio está basado en ejemplos y practicas conocidas y trata a reflejar filosofías practicas del campesinado y las fortalezas y debilidades correspondientes. De lo más énfasis se ha dedicado al chayote en Costa Rica y México, a la pitahaya en Nicaragua, a la papaya en el Estado Tabasco y al mango, rambutan y caña de azúcar en el estado Chiapas, México, y a las huertas familiares en Cuba. Resultados de una encuesta entre consumidores reflejan el interés para consumir productos orgánicos, establecer la interacción agricultores-consumidores como parte del proceso de desarrollo agroecológico y fortalecer la educación de los consumidores y productores en los aspectos agroecológicos y de salud.


2.
Tesis - Maestría
Benefits of irrigation among smallholder farmers in southwestern Nigeria / Opeyemi Anthony Amusan
Amusan, Opeyemi Anthony ; Tischbein, Bernhard (main supervisor) ; Geissen Geissen, Violette (co-supervisor) ; Janssens, Marc J. J. (chair person) ;
Bonn, Germany : University of Bonn. Institute of Water Engineering and Land Improvement , 2006
Clasificación: TE/631.587 / A4
Bibliotecas: Villahermosa
Cerrar
SIBE Villahermosa
ECO050006118 (Disponible)
Disponibles para prestamo: 1

3.
Artículo
Alternatives for the transformation of drug production areas in the Chapare Region, Bolivia
Torrico, Juan Carlos ; Pohlan, Jurgen (coaut.) ; Janssens, Marc J. J. (coaut.) ;
Clasificación: AR/583.60984 :: T6
Contenido en: Journal of Food, Agriculture & Environment Vol. 3, no. 3-4 (2005), p. 167-172 ISSN: 1459-0263
Bibliotecas: San Cristóbal
Cerrar
SIBE San Cristóbal
ECO010019024 (Disponible)
Disponibles para prestamo: 1
PDF
Resumen en: Inglés |
Resumen en inglés

The Chapare region of Bolivia is classified as “humid sub-tropic”. About 92% of the 35,000 families of inhabitants are involved in farming. Until now, 93% of the coca (Erythroxylum coca Lam.) cultivation has been eradicated leading to serious social, economic and ecological problems. The most important agricultural crops grown in the Chapare region are citrus and banana, which occupy 20.8 and 18.8% of the total area under cultivation, respectively. Both crops are intended for the market and therefore play an important role in the economy of the region. Cassava (7.3%) and rice (7.2%) are cultivated for personal consumption. The average area of land possessed by a family amounts to 10.4 ha, but due to lack of capital and high labour costs, only 2.6 ha/family are cultivated. The remaining land (74%) is under forest and fallow. Generally, poor quality seeds are used. The intensive use of agrochemicals is common in the area. Clearing vegetation by burning (chaqueo) is a common activity that causes severe ecological damage. The crops are grown in small plots on small farms and the neighbouring families provide the labour force engaged in crop husbandry and other agricultural activities. The average available family wage is 460 US dollars/year/ha. Sixty five percent of the farms belong to the subsistence economy. They have an average investment capacity of 400- 800 US$/ha (representing 89% of the cases). Alternative cultivation products include banana, pepper, passion fruit, pineapple and palmito, but these provide a limited income (600-2400 US$/ha), which only represents a third to a sixth of the proceeds from coca. The initial investments for alternative crops can ascend to US$1800-5000 provided that proper management and good technical knowledge are made available. The alternative crops available at present do not provide an economically feasible opportunity for the families of this region.

Research should be focused on other alternative crops for sustainable production leading to improved agricultural commercialisation which reinforces the national market. In addition, greater attention needs to be paid to the social aspects of the present problem.


4.
Capítulo de libro - Memoria en extenso sin arbitraje
Conversion process and reforestation practices of coffee plantations in Chiapas, Mexico
Jende, Oliver ; Pohlan, Jurgen (coaut.) ; Janssens, Marc J. J. (coaut.) ;
Contenido en: Tropentag. Conference on International Agricultural Research for Development (October 2005), p. 11-13
PDF
Resumen en: Inglés |
Resumen en inglés

The Agro-ecosystems in the Tropics are nowadays mostly based on annual monocultures. Typically, big forest areas are chopped down and burned with all their biodiversity and complex food chains, to give space to simplified systems reminescent of shifting cultivation. However, the traditional long-term fallowing of exhausted soils is reduced. With perennial crop systems the negative effects of forest logging are mitigated. Today, more than 25 million families on 12 million ha in 50 countries over the World are socially and economically dependent from coffee plantations. The low coffee prices in the world market harm not only these families but also the agro ecosystem coffee, which protects naturally a still considerable flora and fauna (POHLAN, 2002). Chiapas is the most important coffee producing state of Mexico with 31% of the national coffee production. Coffee agro ecosystems in the Soconusco area in Chiapas are under pressure due to these low coffee prices in the world market (RENARD, 2002; KRAUSE, 2002). Coffee farmers have to adapt to this situation by producing high quality coffee with added value through certification labels, or changing the coffee plantations into other more profitable crops (POHLAN, 2002). One of the possibilities for lower tropical areas is the production of high value tropical timber, which can be planted between coffee rows (JENDE, 2005). These agroforestry systems offer also a high potential for environmental services, like conservation of biodiversity, carbon fixation, erosion control and water shed management, what could be used as incentive alternatives for farmers by decision makers (KÖTZ, 2003; BAUMANN, 2002; PERFECTO, 2002; CONAFOR, 2001; DE JONG, 2000). In this study, different aspects of a gradual conversion process from coffee to timber production were evaluated, with the aim to understand, how the agro-ecosystem coffee changes in horizontal and vertical structure, in terms of biomass components, and which ecological


5.
Tesis - Maestría
The conversion process of Chiapas coffee plantations through agroforestry into timber production and its ecological implications / Oliver Jende
Jende, Oliver ; Pohlan, Jurgen (tutor) ; Janssens, Marc J. J. (asesor) ; Wittmann, Dieter (asesor) ;
Bonn, Deutschland : Universität Bonn-Wilhelms. Institut für Gartenbauwissenschaft. Rheinischen Friedrich , 2005
Clasificación: TE/633.73097275 / J4
Bibliotecas: San Cristóbal , Tapachula
Cerrar
SIBE San Cristóbal
ECO010009567 (Disponible)
Disponibles para prestamo: 1
Cerrar
SIBE Tapachula
ECO020012141 (Disponible) , ECO020011301 (Disponible)
Disponibles para prestamo: 2

6.
Artículo
Effects of production systems with maize (Zea mays L.) on soil fertility and biological diversity in the Soconusco, Chiapas, Mexico
Marroquín Agréda, Francisco Javier ; Pohlan, Jurgen (coaut.) ; Janssens, Marc J. J. (coaut.) ; Borgman, Jörg (coaut.) ;
Contenido en: The Global Food & Product Chain – Dynamics, Innovations, Conflicts, Strategies. ID 389. Deutscher Tropentag, October 11 - 13, 2005 in Stuttgart p. 1-6
PDF
Resumen en: Inglés |
Resumen en inglés

The abuse of chemical products in the production systems in the Central American tropical region has caused a series of drastic effects on the natural resources leading to the lowering of yields at medium and long terms. It also destroys sustainable production and depends highly on external inputs such as fertilizers and pesticides. The objectives of the research were to analyze the bases for the implementation of sustainable agriculture practices in Chiapas agricultural systems with maize. The investigation was carried out during cropping cycle 2002–2003 in the region of the Soconusco, Chiapas, Mexico. Four treatments with experimental areas of one hectare each were selected: (i) production system with maize (roza-tumba-quema = slash and burn) with 2 years cropping; (ii) production system with 6 years monoculture maize; (iii) production system with 12 years monoculture maize; (iv) area with tropical rain forest. In each experimental unit the physical and chemical soil properties, the dynamic of weed populations and the productivity of each system were determined, a one-way experimental design with seven levels was applied, each level with four repetitions. The dynamic of the soil fertility of the production systems with maize, indicates that the content of organic C, N total, K, Ca and Mg, was strongly reduced by the duration of maize cultivation. The lowest values were recorded in the maize treatment with 12 years of monoculture, whereas the treatment with 2 years maize cropping demonstrated soil values very similar to the tropical rain forest. To the contrary, P increased in the systems with continuous maize growing.

The weed biomass decreases with maize cropping duration, having the highest biomass production in the treatment with 2 years maize cropping. The diversity of weeds also was reduced by maize cropping duration, encompassing 20 weed species in the treatment with 2 years maize cropping followed with 17 weed species in the 6 years maize monoculture and only 12 weed species in the treatment with 12 years of maize monoculture. The maize yield oscillates significantly between 4353 kg*ha−1 (2 years maize cropping) and 1785 kg*ha−1 (12 years of maize monoculture).


7.
Capítulo de libro
Bridging the gap between integrated and organic agriculture to ensure food security
Janssens, Marc J. J. (autor) ; Gaese, Hartmut (autor) ; Glatzle, Albrecht (autor) ; Pohlan, Jurgen (autor) ;
Contenido en: Conference on International Agricultural Research for Development (2004 : Berlin) Deutscher Tropentag p. 1-8
PDF
Resumen en: Inglés |
Resumen en inglés

Many tropical farming systems are evolving by expanding the cropped area and encroaching on the environment. Most of them are of organic nature and labour unproductive. The developing world is importing countless quantities of cereals, meat and other food, mostly from non-organic farming systems outside the tropics. In fact, the digestive tracts are largely colonised. There are cases where non-subsidised imports can be cheaper than locally produced commodities. Reversing this trend will imply farmer training and a healthy synergism between intensive and organic cultivation techniques. Zero-tillage, enabled by herbicides like glyphosate has gained recognition as a second green revolution step. Seed coating, encompassing whatever fungicides and micro-fertilisers, combined with appropriate seedbed preparation is another such step forward. In horticulture, drip irrigation and plastic tunnels are part of the hinterland of most cities in the tropics.

Prophylactic treatment of crops and animals should be based on health stimulating and target specific principles. In animal husbandry, both feed spectrum and genetic base should be appropriate. Most, intensively produced meat is based on cereal and oilseed feed. However, as prolonged feedlots are ecologically questionable, an increased market share of grass-fed animals from improved, energy saving (sub)tropical pastures should be favoured. To enhance efficient use of inputs; (i) the integrated FAO approach for crop health, plant nutrition, water use and soil management should be encouraged, (ii) the target environment receptive, (iii) multiple use of inputs promoted, and (iv) unwanted residual elements remain below organic threshold levels. In either system, inputs should remain within environmentally acceptable standards. Not all natural substances are beneficial to insects, livestock and humans. Emphasis is put upon “vitalising” selected abiotic inputs into ecologically acceptable inputs and/or substrates.


8.
Capítulo de libro - Memoria en extenso
El cultivo de rambután (Nephelium lappaceum l.) una alternativa para zonas cafetaleras en Centroamérica
Vanderlinden, Eva ; Pohlan, Jurgen (coaut.) ; Janssens, Marc J. J. (coaut.) ;
Contenido en: Convención Trópico 2004: Geografía, Meteorología, Ecología y Agricultura Tropical (9th : La Havana, Cuba : 2004) La Havana, Cuba : Instituto de Investigaciones Fundamentales en Agricultura Tropical Alejandro de Humboldt, Instituto de Geografía Tropical, 2004
PDF

9.
Artículo
Culture and fruit quality of rambutan (Nephelium lappaceum L.) in the Soconusco region, Chiapas, Mexico
Vanderlinden, Eva Johanna María ; Pohlan, Jurgen (coaut.) ; Janssens, Marc J. J. (coaut) ;
Contenido en: Fruits Vol. 59, no. 5 (September 2004), p. 339-350 ISSN: 0248-1294
PDF
Resumen en: Inglés | Frances |
Resumen en inglés

Introduction. In Mexico, the rambutan is not a well-known fruit tree, but it has great potential for its establishment and development in the Soconusco region because of the local good agro-ecological conditions for the production of its fruit. Currently, there are already 200 ha of plantations in the region with a good adaptation and a rewarding yield. Rambutan history, cultivation practices, post-harvest operation and commercialisation in the Soconusco region were studied to identify the possibilities of an expansion of the species. In particular, the work aimed at identifying different varieties inside the rambutan orchards. Materials and methods. Four areas were studied from a survey in 14 farms. Different parameters of fruit quality were analysed (ten trees sampled per farm): fruit diameter, fruit length, rind colour, spintern appearance, aril diameter, aril length, aril weight, flesh colour, flavour, succulence, adherence of flesh, and presence of pests and diseases. Results. Fruit quality was dissimilar for the four studied areas. Among the different fruit samples collected, it appeared that the environment and cultivation management play an important role in fruit size. The diversity of varieties planted in the different sites was determined by clustering analyses. Independent of their site of origin, at least six well-defined cluster classes could be identified. Conclusion. Fruit weight, spintern appearance and colour, as well as fruit diameter and aril to fruit weight appeared to be good indicators to identify fruit quality. The clustering analyses showed that there is a wide range of overlapping varieties to be found in the Soconusco region. Six major varietal groups were identified. Further varietal differentiation and characterisation of rambutan in the Soconusco region will be necessary for a better establishment of this fruit tree crop.

Resumen en frances

Introduction. Au Mexique, le ramboutan n’est pas un arbre fruitier bien connu, alors qu’il offre un potentiel de développement réel dans la région du Soconusco, en raison de conditions agro-écologiques propices à la production du fruit. Actuellement, il y a déjà 200 ha de plantations dans cette région ; l’arbre présente une bonne adaptation et des rendements intéressants. L’histoire du ramboutan, les pratiques culturales, les opérations d’après récolte et la commercialisation dans la région de Soconusco ont été étudiées pour identifier les possibilités d’une expansion de l’espèce. En particulier, nos travaux ont cherché à identifier différentes variétés à l’intérieur des vergers de ramboutan de la zone étudiée. Matériel et méthodes. Quatre zones ont été étudiées à partir d’une enquête effectuée sur 14 exploitations. Différents paramètres de la qualité du fruit ont été analysés (dix arbres prélevés par exploitation) : diamètre et longueur du fruit, couleur de l’écorce, aspect des poils, diamètre, longueur et poids de l’arille, couleur de la chair, saveur, succulence, adhérence de la chair, présence de parasites et maladies. Résultats. La qualité du fruit a été différente pour chacune des quatre zones étudiées. Les différents échantillons de fruit collectés ont montré que l’environnement et la gestion de la culture jouaient un rôle important sur la dimension de fruit. La diversité des variétés plantées dans les différents sites a été déterminée par une analyse typologique. Indépendamment de la localisation des arbres, au moins six classes ont été nettement identifiées par cette méthode.

Conclusion. Le poids du fruit, la couleur de l’écorce, l’aspect des poils, ainsi que le diamètre du fruit ou le rapport (poids de l’arille / poids du fruit), ont semblé être de bons indicateurs pour évaluer la qualité du fruit. Les analyses typologiques ont montré qu’il existe une large gamme de variétés dans la région du Soconusco. Six groupes variétaux principaux ont été identifiés. Davantage de différentiation et de caractérisation des variétés de ramboutan seront nécessaires dans la région de Soconusco pour mieux développer cette culture dans la zone.


10.
Capítulo de libro
Eco-volume and bio-surface interplay with the universal scaling laws both in biology and in the Mata Atlantica
Janssens, Marc J. J. ; Mulindabigwi, Valens (coaut.) ; Pohlan, Jurgen (coaut.) ; Torrico, Juan Carlos (coaut.) ;
Contenido en: Seminário A Cooperação Brasil-Alemanha no Programa mata Atlântica. Teresopolis, 29 November, 3 December 2004 p. 1-15
PDF
Resumen en: Inglés |
Resumen en inglés

The applicability of a scenario or a model is mainly a matter of validation, which in turn will depend on the relevance of the interdisciplinary research hypotheses, on the one hand, and on the integrative if not interdisciplinary nature of the retained variables and/or indicators on the other hand. The notion of agro-climax is proposed as an alternative to that of eco-climax. Each agro-climax is characterised by a certain level of agro-diversity, contributing in its manmade way to biodiversity. The apparent global photosynthesis can be approximated through the measurement of litter fall, using the latter two status definitions. The above ground net primary production is close to fourfold the litter fall. The integrative indicator « eco-volume » enables to better discriminate between vegetation types and farming systems. The eco-volume contributes to supplementary precipitations of ecological origin. Finally, eco-volume is an interconnecting parameter helping validating more complex hydrological models. The ratio of eco-volume to bio-volume, tells how much eco-volume can be colonised per unit of bio-volume. To each bio-volume does correspond a bio-surface, which will regulate gaseous and caloric exchanges between bio-volume and the space encapsulated by the eco-volume. The ratio of bio-surface to ground surface is a direct measure of the vitality and the metabolic efficiency of an eco-system. The alleged universal scaling laws of biology (Enquist et al. 1999) where production and metabolic rate are believed to scale at M3/4 and whereby M is the corresponding biomass, are neglecting the metabolic expenses of the surrounding vegetal environment i.e. an eco-volume within which young plantlets are to develop at a most efficient metabolic rate. Above formula should be corrected both for bio-surface and eco-volume.