Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Answering the "Call of the Mountain" : co-creating sustainability through networks of change in Colombia
    Chaves Villegas, Martha - \ 2016
    Wageningen University. Promotor(en): Arjen Wals, co-promotor(en): Gerard Verschoor. - Wageningen : Wageningen University - ISBN 9789462577251 - 152
    sustainable development - sustainability - social networks - networks - communities - rural communities - change - social change - learning - colombia - south america - duurzame ontwikkeling - duurzaamheid (sustainability) - sociale netwerken - netwerken - gemeenschappen - plattelandsgemeenschappen - verandering - sociale verandering - leren - colombia - zuid-amerika

    In response to the age of the ‘anthropocene,’ as some authors are calling this epoch in which one single species is disrupting major natural systems (Steffen et al 2011), there are calls for more radical, learning-based sustainability that generates deep transformations in individuals and communities so as to transition towards a more reflexive and process-oriented society (Wals 2009, Sterling 2009). The principal contention of this thesis is that new social movements (NSM) of the network society (Castells 2012, Buechler 2016), based on integrated visions of sustainability, can provide platforms for bringing about transformative learning. This thesis is based on empirical research (2012-2016) into a fraction of such NSM named the Council of Sustainable Settlements of Latin America (C.A.S.A.). Comprising a diversity of members from Indigenous pueblos, afro-colombian communities, neo-rural settlements (ecovillages), Hare Krishna communities, campesino farmers, NGOs and urban peoples and initiatives, the C.A.S.A. network organizes intercultural exchanges where transformative learning can be traced. Through new forms of collective action centered on a plurality of ideas and practices, and with a strong focus on reflection and personal development, in such encounters through ‘ontological politics’, ‘optimal dissonance’ and ‘deep reflexivity and flexibility’ members are articulating new paradigms of alternative development and creating spaces for transformation. Yet, such learning processes are incredibly complex, and the value-action gap remains substantial in many cases. What this thesis has shown, however, is that by putting into practice principles of buen vivir and the pluriverse such as reconnecting to ancestral wisdom, acknowledging the other, questioning values of competition and consumerism, and forming new relations to place and territory, one begins to question one's own set of norms, and those of society. Ultimately, the C.A.S.A. network’s struggles, negotiations and learning processes remind us that global sustainability entails more than 'menus' of good practices but a plurality of solutions which include humans and non-humans, different ontologies, and even a multiplicity of worlds, in what is a tough but rewarding aula.

    Fairtrade certification in the banana hired labour sector
    Rijn, F.C. van; Judge, L.O. ; Fort, Ricardo ; Koster, Tinka ; Waarts, Y.R. ; Ruben, R. - \ 2016
    Wageningen : LEI Wageningen UR (LEI report 2015-056) - ISBN 9789086157129 - 146
    bananas - plantations - fair trade - certification - international trade - hired labour - working conditions - ghana - dominican republic - colombia - bananen - beplantingen - fair trade - certificering - internationale handel - loonarbeiders - arbeidsomstandigheden - ghana - dominicaanse republiek - colombia
    Evidence is needed about the difference that certification makes to workers on banana plantations. The Fairtrade system is therefore investing in monitoring to understand the difference certification makes to banana workers’ employment, living and working conditions, and empowerment. This study meets this need by gathering data on a range of indicators. This study 1) gathers baseline data on indicators and themes that monitor the progress of implementation of Fairtrade’s revised hired labour standards on certified plantations in key banana origins; 2) based on this data it researches and analyses the difference that Fairtrade makes across key themes in comparison to non-certified contexts; it prioritises workers’ voices and perspectives in achieving the objectives of the study. It particularly focuses on understanding the role of Fairtrade in supporting worker empowerment and empowerment-related goals. Focus countries are Ghana, Colombia and the Dominican Republic.
    Marine and coastal ecological potential for the economic development of Colombia
    Rozemeijer, M.J.C. - \ 2013
    IJmuiden : IMARES (Report / IMARES C179/13) - 16
    coastal management - marine environment - ecosystem services - economics - colombia - kustbeheer - marien milieu - ecosysteemdiensten - economie - colombia
    PES, peasants and power in Andean watersheds : power relations and payment for environmental services in Colombia and Ecuador
    Rodriguez de Francisco, J.C. - \ 2013
    Wageningen University. Promotor(en): Linden Vincent, co-promotor(en): Rutgerd Boelens; J. Budds. - Wageningen : Wageningen UR - ISBN 9789461737861 - 179
    hulpbronnenbeheer - natuurlijke hulpbronnen - beheer van waterbekkens - ecosysteemdiensten - inheemse volkeren - plattelandsgemeenschappen - milieubeleid - andes - colombia - ecuador - landbouw bedrijven in het klein - resource management - natural resources - watershed management - ecosystem services - indigenous people - rural communities - environmental policy - andes - colombia - ecuador - peasant farming

    During the last decade, the market environmentalist policy model of Payment for Environmental Services (PES) has become a widely promoted and implemented conservation and development tool, around the world as well as in the Andean countries Colombia and Ecuador. For upstream peasant indigenous communities in the Andes, the great expansion of this policy model has meant an increased level of negotiations and interactions with a wide range of downstream water users and conservation agencies. However, there is not a clear understanding of how power dynamics influence the terms of exchange in watershed PES schemes, and the implications that these dynamics have for peasant indigenous control of, and access to, natural resources. The main research question of this thesis is: How do power relations influence the promotion of PES as a policy model and the crafting and operation of PES (-like) projects, and how in turn do these influence natural resource management and control by PES-targeted peasant communities, in the Andean regions of Colombia and Ecuador? The cases included in this thesis show how the impacts of these forms of power influencing PES schemes are variegated, but for the poorest they appear to work toward the deeper entrenching of the status quo, which in most cases implies confirmation and extension of unequal access and rights to natural resources.

    'Acompañarnos contentos con la familia' : unidad, diferencia y conflicto entre los Nükak (Amazonia colombiana)
    Franky Calvo, C.E. - \ 2011
    Wageningen University. Promotor(en): Georg Frerks, co-promotor(en): Pieter de Vries; Gerard Verschoor. - [S.l.] : S.n. - ISBN 9789085859475 - 283
    etnografie - jagers en verzamelaars - inheemse volkeren - amazonia - colombia - latijns-amerika - conflict - uitsterven - sociale structuur - ethnography - hunters and gatherers - indigenous people - amazonia - colombia - latin america - conflict - extinction - social structure
    The Nükak are a people of hunters and gatherers in the Colombian Amazon who call themselves Nükak baka', which can be translated as ‘the true people’. More than a name, this denomination designates a shared moral and political project that enables this people to reproduce themselves materially and socially, to guide their individual conduct, to perpetuate and fertilize the cosmos and to steer their relationships with the other peoples of the universe. In this sense this project constitutes a biopolitics, or to put it differently, it is a politics oriented toward the creation and defense of life. This thesis, therefore, is an ethnographic research about what it means for the Nükak to live as a ‘true people’. It shows that such a common project constitutes above all a set of practices that is continuously being actualized, both in terms of individual conduct as well as in terms of collective interactions and activities. These become materialized in aspects such as the preservation of the environment and the construction, and care, of the body. For that reason living as ‘true people’ is neither a given condition nor a status that once attained can be maintained until death. Being an incomplete process, for the Nükak the constitution of ‘true people’ is continuously under threat. This means that their reproduction and the continuity of the universe is always at risk. These threats originate in actions, emotions and amoral attitudes of the Nükak themselves, or of other beings in the cosmos, which express themselves in situations such as illness or inter-personal conflicts. As a result the everyday life of this group unfolds within a continuous tension between the actualization of the project of constituting ‘true people’ and the threat of biological and social extinction, even the destruction of the cosmos. From a different perspective, this thesis is concerned with practices of ‘living together’, of accompanying each other, of sharing, of establishing kin relations in order to strengthen the common, and of finding out what they have in common. It is also about how to deal with possible sources of division. Finally, the thesis sets out to show how this group actualizes a sense of unity and diversity that enables them to create Nükak baka, i.e. ‘true people’, thus articulating differences without denying them. In order to develop these topics, the thesis explores the major features of the project of creating, and living as, ‘true people’, as well as a number of strategies and mechanisms (or social dispositifs) that the Nükak have generated for its actualization. It also examines the ontological and mythical bearings, going back to the times of the creation of the cosmos, which enables us to understand, from the perspective of the Nükak, with what peoples and beings they are interacting. In this sense the thesis contributes to the actualization of basic ethnographic information and elaborates on Nükak’s theories and practices concerning social life, the body, notions of the person, relations between kin, relations with other peoples and beings in the cosmos, shamanism, and narratives about the experiences of the ancestors who form part of their historical memory. This thesis also contributes to the documentation of the impact of the armed conflict in Colombia on the Nükak, clarifying the heterogeneity and complexity of the circumstances that have led to the forced displacement of different groups of Nükak, as well as the institutional and media attention that these groups have received.
    Productivity and Trade Orientation in UK Manufacturing
    Rizov, M.I. ; Walsh, P. - \ 2009
    Oxford Bulletin of Economics and Statistics 71 (2009)6. - ISSN 0305-9049 - p. 821 - 849.
    export - entry - firms - exit - liberalization - colombia - dynamics - inputs - plants - costs
    We show that improvements in aggregate productivity in UK manufacturing during the first years after the implementation of the Euro, by the UK's main trading partners in Europe, are determined by both market share reallocation and within-company productivity growth. Furthermore, we outline a structural methodology for estimating parameters of a production function linking the unobservable productivity to endogenous company-level trade orientation, investment and exit decisions. This allows us to back out consistent and unbiased estimates of productivity dynamics by trade orientation of companies within four-digit UK manufacturing industries using FAME data over the period 1994–2001. Our estimates of productivity dynamics indicate that improvements in aggregate productivity were mainly driven by market share reallocations away from inefficient and towards efficient exporting companies alongside productivity improvements within non-exporting companies
    The forest vegetation of Ramal de Guaramacal in the Venezuelan Andes
    Cuello, A.N.L. ; Cleef, A.M. - \ 2009
    Phytocoenologia 39 (2009)1. - ISSN 0340-269X - p. 109 - 156.
    montane rain-forest - tropical mountains - fog interception - cloud forests - costa-rica - cordillera - colombia - zonation
    Montane forest community composition of Ranial de Guaramacal, Venezuelan Andes, was studied along the altitudinal gradient on both sides of the range with different slope expositions. Thirty five 0.1 ha plots were Surveyed, with variable intervals of 30 to 150 meters between 1350 in and 2890 in and mile plots of variable size (50 m(2) to 400 m(2)) Were surveyed in dwarf forests located between 2800-3050 m. A total of 388 morphospecies with dbh >= 2.5 cm, corresponding to 189 genera and 78 families of vascular plants, were recorded from a total of 45 forest plots. The TWINSPAN phytosociological classification, based on both floristic composition and species relative abundance, revealed seven forest communities,it association level, grouped in three alliances and one montane forest order group. Three subandean forest (LMRF) communities and four Andean - high Andean forest (UMRF-SARF) communities are distinguished and described according to the Zurich-Montpellier method. The Geonomo undatae-Posoquerion coriaceae alliance contains two subandean forest communities (Simiro erythroxyli-Quararibeetum magnificae and Conchocarpo larensis-Coussarectum moritzianae); the Farameo killipii-Prunion moritzianae alliance contains one subandean forest community, (Croizatio brevipetiolatae-Wettinietum praemorsae) and one Andean forest community (Schefflero ferrugineae-Cybianthetum laurifolii) and the Ruilopezio paltonioides-Cybianthion marginatii alliance includes one Andean (Geissantho andini-Miconietum jahnii) and two high Andean forest communities (Gaultherio anastomosantis-Hesperomeletum obtusifoliae and the Libanothamnetum griffinii). Altitudinal zonation, forest floristic diversity, composition and forest structure is discussed between slopes and along the altitudinal gradient and compared, where possible, to other montane forests. In LMRF, Rubiaceae, Lauraceae and Melastomataceae are the most speciose of woody families. In UMRF, the Lauraceae family is still the most diverse, followed by Melastomataceae and Myrtaceae, while in SARF the Asteraceae and Ericaceae are the most species rich families. The structure of the montane forests of Ramal de Guaramacal becomes more compressed towards higher elevations. LMRF are dense and of medium height, with canopies up to 25 in tall, while UMRF canopies can reach up to IS in, and those of SARF are only 6-8 (10) m tall. Basal area was slightly increased on the North than on the South slopes and shows different patterns against altitude between slopes. More diversity and density of palms, lianas and climbers is clearly observed in LMRF, but richness of liana species is also important in SARF forests. Forest altitudinal zonation is variable between the North and South slopes of Guaramacal, with the forest zones of UMRF on the windward South slope, tending toward reaching lower elevations than on the opposite and drier North slope. There is a low altitudinal limit of the upper forest (Upper Forest Line or UFL) apparently caused by the "top effect"
    Tephra stratification of volcanic ash soils in Nothern Ecuador
    Tonneijck, F.H. ; Hageman, J.A. ; Sevink, J. ; Verstraten, J.M. - \ 2008
    Geoderma 144 (2008)1-2. - ISSN 0016-7061 - p. 231 - 247.
    undisturbed paramo grasslands - colombia - geochemistry - profiles - andosols - biomass - pollen - mass
    We combined proxies traditionally used in stratigraphic research (mineral assemblages, grain size distribution, and element ratios) with soil organic carbon contents and radiocarbon dating both at a high vertical resolution, to unravel the tephra stratigraphy in volcanic ash soils. Our results show that soil profiles along an altitudinal transect intersecting the upper forest line in Northern Ecuador were formed in three distinct tephra deposits. Although the deposits contained a similar assemblage of minerals, we were able to differentiate these deposits because of their characteristic organic carbon distribution, grain size distribution and typical SrO to Na2O, CaO and crystalline Al2O3 ratios. Unravelling the tephra stratigraphy improved understanding of the vertical distribution of soil organic carbon, including paleoecological proxies, in the studied soils. We demonstrated that bioturbation likely plays an important role in current pedogenesis, resulting in overprinting (merging, mixing) of the paleosol. Surprisingly, in spite of bioturbation, a linear age depth relationship exists, leading to the hypothesis that the active zone of bioturbation shifted upwards during soil formation. Therefore, we conclude that paleoecological proxies are stratified in our soils, albeit probably somewhat more crudely than in undisturbed peat bogs or lake sediments.
    From the Amazon to the Supermarket: Innovation and the integration of small-scale Amazonian chilli-pepper producers in green markets (Leticia, Colombia)
    Verschoor, G.M. ; Boliívar, E. ; Ochoa, G. ; Muradian, R. - \ 2008
    London : Sustainable Markets Group, International Institute for Environment and Development (IIED) (Regovering Markets : Small-scale producers in modern agrifood markets ) - 33
    kleine landbouwbedrijven - innovaties - markten - spaanse pepers - specerijen - colombia - zuid-amerika - ontwikkelingseconomie - small farms - innovations - markets - chillies - spices - colombia - south america - development economics
    Nutritional and health status of woolly monkeys
    Ange-van Heugten, K.D. ; Timmer, S. ; Jansen, W.L. ; Verstegen, M.W.A. - \ 2008
    International Journal of Primatology 29 (2008)1. - ISSN 0164-0291 - p. 183 - 194.
    lagothrix-lagotricha-poeppigii - tinigua-national-park - reproductive parameters - feeding ecology - colombia - patterns - forest - diet - wild - toxoplasmosis
    Woolly monkeys (Lagothrix lagotricha and L. flavicauda) are threatened species in the wild and in captivity. Numerous zoological institutions have historically kept Lagothrix lagotricha spp., but only a few of them have succeeded in breeding populations. Therefore the majority of institutions that formerly kept Lagothrix lagotricha are no longer able or willing to do so. Captive populations of the species have frequent health problems, most significantly hypertension and related disorders. Researchers have conducted free-ranging dietary and behavior studies with respect to woolly monkeys, but have established no concrete link between diet or nutrients and captive health problems. The available literature we discuss indicates that researchers need to examine the link further. In addition, it is critical to the survival of the primates to be able to keep breeding populations in captivity owing to increasing natural pressures such as deforestation and hunting. Therefore, better understanding of the captive and free-ranging behavior and health parameters of the species is vital to ensure their survival and to maintain forest health and diversity. Researchers need to conduct large-scale research studies comparing the health and complete diet of individuals in the wild and captivity to resolve health problems facing the species in captivity.
    La Cordillera Oriental Colombiana, Transecto Sumapaz
    Hammen, T. van der; Rangel, J.O. ; Cleef, A.M. - \ 2008
    Berlin-Stuttgart : J. Cramer (Studies on tropical Andean ecosystems vol. 7) - ISBN 9783443500320 - 1009
    ecosystemen - tropen - vegetatie - bossen - natuurbescherming - colombia - andes - ecosystems - tropics - vegetation - forests - nature conservation - colombia - andes
    The publication of this volume (volume 7) concludes the publication of the study of the Transects of Buritaca (Sierra Nevada de Santa Marta), Parque Los Nevados (Cordillera Central), Tatamá (Western Cordillera) and Sumapaz (Eastern Cordillera) in the Colombian Andes. The latter three studies represent a West-East transect through the Colombian Andes, from the Pacific to the Llanos Orientales (Eastern Plains) at an approximate latitude of 4 ° North.
    The Holocene treeline in the northern Andes (Ecuador): First evidence from soil charcoal
    Pasquale, G. Di; Maziano, M. ; Impagliazzo, S. ; Lubritto, C. ; Natale, A. De; Bader, M. - \ 2008
    Palaeogeography Palaeoclimatology Palaeoecology 259 (2008)1. - ISSN 0031-0182 - p. 17 - 34.
    south-america - french alps - biome reconstructions - vegetation structure - maurienne-valley - fire history - costa-rica - pollen - colombia - alpine
    Indications for the speed and timing of past altitudinal treeline shifts are often contradictory. Partly, this may be due to interpretation difficulties of pollen records, which are generally regional rather than local proxies. We used pedoanthracology, the identification and dating of macroscopic soil charcoal, to study vegetation history around the treeline in the northern Ecuadorian Andes. Pedoanthracology offers a complementary method to pollen-based vegetation reconstructions by providing records with high spatial detail on a local scale. The modern vegetation is tussock grass páramo (tropical alpine vegetation) and upper montane cloud forest, and the treeline is located at ca. 3600 m. Charcoal was collected from soils in the páramo (at 3890 and 3810 m) and in the forest (at 3540 m), and represents a sequence for the entire Holocene. The presence of páramo taxa throughout all three soil profiles, especially in combination with the absence of forest taxa, shows that the treeline in the study area has moved up to its present position only late in the Holocene (after ca. 5850 cal years BP). The treeline may have been situated between 3600 m and 3800 m at some time after ca. 4900 cal years BP, or it may never have been higher than it is today. The presence of charcoal throughout the profiles also shows that fires have occurred in this area at least since the beginning of the Holocene. These results contradict interpretations of palaeological data from Colombia, which suggest a rapid treeline rise at the Pleistocene¿Holocene transition. They also contradict the hypothesis that man-made fires have destroyed large extents of forest above the modern treeline. Instead, páramo fires have probably contributed to the slowness of treeline rise during the Holocene.
    Impact of solid shrimp pond waste materials on mangrove growth and mortality: a case study from Pak Phanang, Thailand
    Vaiphasa, C. ; Boer, W.F. de; Skidmore, A.K. ; Panitchart, S. ; Vaiphasa, T. ; Bamrongrugsa, N. ; Santitamnont, P. - \ 2007
    Hydrobiologia 591 (2007)1. - ISSN 0018-8158 - p. 47 - 57.
    algal toxicity - aquaculture - effluent - ecosystems - antibiotics - chemicals - colombia - removal - ecology - wetland
    One of the most serious threats to tropical mangrove ecosystems caused by shrimp farming activities is the poor management of pond wastematerials.We hypothesise thatmangroves can tolerate chemical residues discharged from shrimp farms and can be used as biofilters, but the capability of mangroves to cope with solid sediments dredged from shrimp ponds is limited. Our study in Pak Phanang, Thailand, confirmed that the excess sediments discharged from nearby shrimp ponds reduced mangrove growth rates and increased mortality rates. A series of transformed multitemporal satellite images was used in combination with the field data to support this claim.In addition, a comparison between four dominant mangrove species revealed that Avicennia marina could tolerate sedimentation rates of >6 cm year¿1, while Bruguiera cylindrica tolerated sedimentation rates of 5 cm year¿1 (total sediment depth = 25 cm) before dying, while Excoecaria agallocha and Lumnitzera racemosa performed intermediate. This outcome implied that in our situation A. marina and to lesser extent E. agallocha and L. racemosa could be more effective as biofilters than B. cylindrica, as theymay survive the sedimentation longer in the disposal areas. Further studies on the impact of sedimentation and chemical pollution of shrimp farmwastes on mangrove mortality and growth are required.
    Sustainable management after irrigation system transfer : experiences in Colombia - the RUT irrigation district
    Urrutia Cobo, N. - \ 2006
    Wageningen University. Promotor(en): E. Schultz. - [S.l. ] : S.n. - ISBN 9789085044956 - 289
    irrigatiesystemen - overdracht - bedrijfsvoering - regering - instellingen - zelfbeheer - duurzaamheid (sustainability) - colombia - associaties - irrigation systems - transfer - management - government - institutions - self management - sustainability - colombia - associations
    Colombiais a tropical country located in South America. It has a total area of 114 million ha. In Colombia two irrigation sectors are distinguished: the small-scale irrigation and the large-scale irrigation sector. The small-scale irrigation sector is developed on lands located on sloping areas, where food crops and cash products such as corn, potato and specially vegetables are cultivated. In these areas the technique of cultivation is not well developed and therefore agriculture with advanced technology is not yet found there. Small farmers with a low income, a high level of illiteracy and malnutrition, form the main part of the traditional sector. The large-scale irrigation sector corresponds to large landholdings, located on the flat areas and with soils of good quality, that are destined for the cultivation of cash crops such as sugar cane, cotton, sorghum, fruit trees, etc. In this type of cultivation mechanization prevails and advanced irrigation technologies are applied.

    The area of the large-scale irrigation sector that corresponds to the public sector is grouped in 24 irrigation districts covering 264,802 ha; 132,918 ha with an irrigation and drainage infrastructure and 131,884 with only drainage. The area covered by the irrigation districts has a total capacity of around 500 m 3 /s; the irrigation network is 1,905 km long, of which 37% is for the main canals, 45% for the secondary canals and 18% for the tertiary canals; the drainage network is 2,132 km long, of which 44% is for the main drains, 39% for the secondary drains and 17% for the tertiary drains; and the road network is 3,382 km long. About 9% of the land is used for permanent crops, 51% for non-permanent crops and 40% for grass. About 62% of the landholdings is smaller than 5 ha and cover about 9% of the total area, 17% of the properties is in the range of 5-10 ha and covers 13% of the area, about 16% of the landholdings is in the range of 10-50 ha, while 3% of the farms is larger than 50 ha and cover 38% of the total area.

    Potential for irrigated agriculture

    At the global scale, Colombia is considered as a country with abundant natural resources, especially in relation to the land and water resources that present a great potential for the development of agriculture under irrigation.

    Soils.The Agustin Codazzi Geography Institute (IGAC) carried out the soil study for Colombia in 1973. Two soil types were distinguished. The type-A soils correspond to the soil classes I, II and III and are suitable for mechanization, intensive agriculture and livestock, and for the development of irrigated agriculture. These soils are mainly located in the Caribbean plains and in the Orinoquia and Amazon regions. Most of the type-B soils correspond to class IV; their ground surface varies from flat to concave-flat requiring among others land improvement like flood protection, drainage, and leaching. Once they are improved, their potential use is similar to the soil type A. The type A and B soils together constitute a potential area of 10.6 million ha for mechanized and irrigated agriculture.

    Water resources.According to the World Water Balance and Water Resources for the Earth of UNESCO, Colombia has a specific surface water yield of 0.59 l/s per ha, and the country occupies the fourth place at world level. This specific yield is six and three times larger than the values for the continental world and Latin America, 0.10 and 0.21 l/s per ha, respectively.

    Colombiahas an average annual rainfall of 1,900 mm. On 70% of the area the average annual rainfall is 2,000 mm or more and on almost one third of the area the rainfall is more than 4,000 mm (Pacific Coast and East plains). These values are above the average of 1,600 mm per year for Latin America, and above the global average of 900 mm per year. In contrast, the Caribbean Coast has little rainfall and is considered as a dry region.

    Colombiahas more than 1,000 perennial rivers, a figure that is larger than for Africa (60). It has 10 interior rivers, which have an average annual discharge greater than 1,000 m 3 /s. Colombia has a natural drainage network of 740,000 micro-basins in view of the high rainfall, topography and geology. This natural drainage is distributed in 4 regions or main river basins.

    Irrigation development. Colombia contributes less than 3% of the irrigated land area in Latin America, occupying the sixth place among the South American countries in view of irrigated lands over the total cultivated lands (12.5%). Colombia has followed a similar tendency as the Latin American region for its irrigation development. The area increased rapidly up to the end of 1960s, but the growth considerably dropped during the last two decades. During the period 1990 - 2000 the public sector concentrated its resources on the rehabilitation, completion and enlargement of the existing irrigation districts.

    Expectations for the irrigated agriculture.According to the National Water Study of 1984 Colombia has 14.4 million ha suitable for agriculture, of which 6.6 million ha (45.8%) are suitable for mechanized agriculture and the development of irrigated agriculture through irrigation and drainage infrastructure. This figure could be increased to 10.6 million ha after the improvement of some soils, which at present limit the conditions for agricultural use. Of these 6.6 million ha only 11.4% has an infrastructure for irrigation and drainage, of which 38% has been developed by the public sector and the remainder by the private sector.

    The Colombian Government established the "Decade Land Improvement Program for 1991 - 2000" to improve 535,500 ha with an irrigation and drainage infrastructure. During the different periods the Government has adapted the land improvement policies with the purpose to follow the preliminary land improvement program that was established for this period by the National Planning Department. However, the land improvement programs had a slow development.

    Policy for the land improvement sector. The historic development of the land improvement in Colombia has been largely influenced by the policy as established by the different governments, which have implemented their policies through the formulation of respective legal frameworks. The policy for the land improvement sector has changed by mandate (directive) after mandate, which did not permit a consistent development on the long term.

    The political outlines of the Colombian Government for the sub-sector of land improvement were enclosed in the Economic-Social Development Plan for the period 1991 - 2000. In 1991 the Colombian Government considered that the public and private investments are good mechanisms to contribute to the modernization of the agricultural production. The investments in land improvement projects would preferably have to be promoted and developed jointly by the public and private sector. To facilitate the investment recovery the Government tried to promote community participation during the design process of the projects, which after construction would be transferred to the water users associations for administration, operation and maintenance. A new institutional framework was proposed in which the Government would change its role from being a simple executor to more an investment promoter with a major involvement of the community.The law 41 (1993) set up the rules by which the land improvement sector was organized.

    After 7 years of land improvement programs within the new institutional framework, strong criticism rose in view of the role of the governmental agency due to a ineffective management of the economic resources and an almost zero-development of the land improvement programs launched from 1990 by different governmental programs. The criticisms were among others related to the management of external resources for the land improvement program, the costs for the functioning of the agency, and the quality of the agency's performance.

    As a result, a change in the institutional framework was introduced at the beginning of 2003 and the existing Governmental Agency for the Land and Improvement Sector and other public institutions within the public agricultural sector were suppressed and integrated in a new organization called Colombian Institute for Rural Development (INCODER). The Agreement 03 of February 2004 was considered as a key element within the new institutional framework by which organizational guidelines were established for the users' organizations including the basic regulation for the functioning of the small, middle and large irrigation districts. However, this agreement contained controversial points causing a new regulation for the administration, operation and maintenance of the irrigation districts including the transfer forms (delegation, administration, and concession) and considering that INCODER must not have direct interference in the water users organizations, but only in the management of the infrastructure (Resolution 1399/2005).

    Irrigation management transfer

    At the middle of the 1970s the Colombian Government started a program to transfer the irrigation management to water users associations. The transfer of irrigation districts in Colombia has been carried out during three periods. In 1976, the irrigation districts Coello and Saldaña were transferred by request of the water users. The Rio Recio, Roldanillo-La Union-Toro (RUT), Samaca, and San Alfonso Irrigation Districts were transferred during the period 1989-1993 and finally, during 1994-1995, most of the remaining irrigation districts were transferred following the policy established by the Colombian Government. At the moment, 16 irrigation districts out of 24 have been transferred and the remaining districts are still under the administration of the Government Agency.

    However, serious problems were detected during and after the transfer process concerning disputes on water rights and legal aspects, inadequate operation and maintenance of the hydraulic infrastructure, disagreement about the role of the Government Agency and water user associations, environmental degradation, problems related to economic and financial aspects, insufficient community participation, lack of leadership, and insufficient training and irrigation management. For some irrigation districts, these problems and constraints resulted in an inefficient performance, deterioration of the physical infrastructure and conflicts related to the operation, maintenance and administration of the system causing an unsustainable development of the irrigation districts.

    In the framework of this research the background of the transfer program in Colombia, its implementation, current status and impacts were reviewed. In this way the irrigation districts of Rio Recio, Coello, Saldaña , Zulia and Maria La Baja were visited and fieldwork and interviews with technical staff and farmers were carried out. Staff from the Government Agency for the Land Improvement Sector, and from private and public entities at local and regional level was also contacted. A review of some experiences and characteristics of the transfer of the irrigation management in other countries with similar characteristics as Colombia was also carried out.

    The experiences with the transfer of irrigation management in Colombia showed that the governmental financial burden was significantly reduced by the shift of the total costs for administration, operation and maintenance to the water users associations. The partial and in many cases the total elimination of the subsidies and the reorganization of the new institutional structure for the Land Improvement Sector facilitated the implementation of the decentralization and delegation policy for the sector. The impact of the delegation of functions to regional and local institutions can not yet be evaluated, because the institutions only recently started to take up their tasks after the delegation; however, scepticism exists among the water users' organizations concerning the effective action of this delegation.

    The development of the transfer program showed a clear difference between the first phase of the transfer program and the following stages. During the first phase the management transfer was promoted by the users themselves and showed a clear opposition of the Government Agency; while for the following phases the motivation came mainly from the Government and was interpreted by the users as a governmental strategy to face the fiscal crisis of the 1990s and to obtain the acquired compromises with the international banking.

    About 30 years after the start of the transfer program the researched water users organizations offered diverse grades of development. Some of them, presented a very well developed organizational stability (Rio Recio, Coello, Saldaña Irrigation Districts) based on financial self-sufficiency as a result of the provision of adequate and reliable irrigation water services; other districts as Maria La Baja showed a serious organizational crisis that resulted in a governmental intervention. The Zulia Irrigation District presented a great organizational model with a dynamic character that was based on an integral and participatory approach around profitable agricultural activities that were focused on rice production and on a clear vision of the future development of the organization. Subsequently, it can be said that in the post-transfer process and from organizational point of view three crucial phases seem to take place: namely adaptation, maturity or full development, and consolidation.

    An increase in efficient water use was another objective of the management transfer to the water users associations. However, observations during the research showed that the water use in the irrigation districts is a critical issue that will hamper the environmental sustainability of the irrigation systems. The financial self-sufficiency as a result of the water selling for the provision of irrigation water, especially for crops demanding large quantities of water like rice seemed to be a factor which did not contribute to the efficient use of irrigation water.

    From environmental point of view it has to be mentioned that the growing deforestation process affects the watersheds of the main surface waters of most of the researched irrigation districts. This situation affects amongst others the quality and costs of the maintenance and operation activities and the availability of the water resource.

    Lastly, the experience of the irrigation management transfer in Colombia allowed for the consideration of a wider concept of the role of an irrigation system. An irrigation system must not be considered as a simple hydraulic infrastructure that only provides irrigation water to the farmers, but it should be recognized as an important component of a production system, whose final objective is to contribute to the improvement of the living conditions of the farmers through irrigated agriculture under criteria of profitability, equity, efficiency, and an integral and participative management approach.

    Sustainable management of transferred irrigation systems; conceptual framework

    A conceptual framework for the sustainable management of irrigation districts transferred to water users associations is formulated and developed based on general concepts and approaches of sustainable water management and especially the sustainable use of land and water resources and the management of land and water systems.This framework is supported by certain general principles, approaches and definitions, some of which were stated in numerous events and conferences concerning improvement and preservation of the natural resources with special emphasis on land and water resources.

    The sustainability of an irrigation and drainage system refers to the physical and organizational infrastructure for management, administration, operation and maintenance during the lifetime of the system according to established specifications and giving the users the expected benefits without causing damage to the environment. The concept of sustainability involves three elements that play an important role in the definition of the conceptual framework for sustainable management of an irrigation system. The three components are Community (C), Environment (E), and Science & Technology (S&T) and they are interconnected within the existing institutional and legal contexts. This interrelationship determines the sustainability of an irrigation system.

    Community (C) represents the different interest groups in the irrigation and drainage sector; in which the farmers are the main beneficiaries. The community with its specific socio-economic-cultural characteristics and organizational forms interconnects with the Environment and Science & Technology components in order to contribute to the sustainable management of the systems. Environment (E) provides the natural resources for irrigated agriculture as production system. Climatic conditions, soils, ecosystems, and water resources are the main inputs provided by the environment component. Factors that affect the relationship between Environment and Community in two directions form risk factors. Science and Technology (S&T) represents the scientific and technological knowledge, methods, tools, and experiences that are available and can be used for the community with the purpose to intervene in the natural environment in order to satisfy its needs and desires.The Science & Technology constitutes the mechanism by which the risk factors for the relation between Environment and Community can be controlled or overcome. The technological alternatives for the provision of an irrigation and drainage service must be in line with the cultural, socio-economic, technical, and financial conditions of the Community. The level of service specifications, cost of the service, willingness to pay for the service provision, organizational forms, technical capacity, participation for operation and maintenance, decision-making, conflict resolution, and resource mobilization, play an important role in the relation Science and Technology and Community.

    RUT Irrigation District

    The RUT Irrigation District was taken as case study for this research. The historic background; description and characteristics of the physical, management and socio-economic aspects of the district; and finally the characteristics and impacts after the transfer process are presented. The RUT Irrigation District is located in the South-west of Colombia, in the northern part of the Valle del Cauca Department. It lies within the three municipalities that give their name to it, namely Roldanillo, La Union, and Toro. The altitude of the district ranges between 915 and 980 m+MSL (Mean Sea Level). Before the construction of the RUT Irrigation District the area was regularly subject to floods from both the Cauca River and the streams descending from the Western Mountain Range. As a consequence an area of 1,500 and 3,500 ha was under permanent and periodic floods respectively. As a result of the high water an area of about 2,500 ha had a high moisture content that only allowed the growth of grass, and an area of 4,000 ha that could only be used for extensive cattle breeding.

    In general terms, the irrigation system is primarily a flood protection and irrigation/drainage scheme. The long and narrow bowl-shaped area is surrounded by a protection dike, running along the East border with the Cauca River and a flood interceptor canal on the West side. A main drain divides the area almost in half, running through the lowest elevations. Parallel to the river dike is the main irrigation canal, which is served by three pumping stations with a total capacity of 13.8 m 3 /s. The flood interceptor canal also acts as an irrigation canal for the water users who use small centrifugal pumps to serve their individual needs. There is a complementary network of both irrigation and drainage canals throughout the area. The main drain discharges freely into the Cauca River during low stages and the drainage water is pumped during the high stages of the river.

    The RUT Irrigation District is one of the most important irrigation systems in Colombia. The district has excellent characteristics for the development of agriculture, namely the good quality of the available natural resources (climate, soils, and water), its strategic geographical location, and its potential for further agro-industrial development in view of national and international markets. Nowadays, the RUT Irrigation District shows a growing crisis, which is a serious threat for the sustainability of the whole system, when the necessary measures are not taken on short notice. External and internal factors; with their social, economic, environmental, technical, and institutional characteristics have contributed in different grade to this situation.

    From its early beginning, the management of the RUT Irrigation District has met a strong opposition from the local community that considered the irrigation scheme as one imposed by the National Government. As many projects of the 1960s and 1970s, also this project was developed with minimal participation of the local community and under almost total responsibility of the Government, who considered the implementation and development of a land improvement project completely as mere physical interventions with limited attention to the social, cultural, and economic requirements within an acceptable social context. Therefore, the farmers showed a very low sense of togetherness and they believed that it was the responsibility of the Government to carry out all the administration, operation and maintenance activities. During the administration of the district by the Government (1971-1989), this attitude did not have a serious impact, because the government agency was in charge of the whole management that included the operation and maintenance of the system with financial resources provided by the government. However, the paternalistic attitude of the land improvement sector, the negative impact of the canal alignments on their farms and agricultural practices, insufficient compensation for their land acquired by the Government for construction works, and lack of credibility of the investment project did not improve the motivation and attitude of the farmers.

    After the transfer in 1989, the Water Users Association ASORUT became fully responsible for the administration, operation and maintenance activities covering all the costs without any subsidy from the Government. The actual transfer was mainly focused on activities related to the organization of the water users association and on considerations concerning water charges and repair of the intake and main canal. Even today, the farmers believe that the transfer has been too rapid without sufficient assistance from the Government side and that the main objective of the Government was an as-fast-as possible management transfer of the irrigation district in order to satisfy the wishes of international financial entities that were interested in the land improvement sector. The main focus of the present management is the provision of irrigation water, from which they will obtain the necessary revenues for the financing of the organization. As the present organization is acting in a comparable way as the previous government agency, the stakeholders believe that the transfer process brought only a change of actors within the management.

    Some time later ASORUT faced the following main negative characteristics: low collection of water charges, temporal and spatial suspension of the maintenance activities for the irrigation network, a low quality of the provided irrigation services, an inefficient use of the irrigation infrastructure and irrigation water, conflicts amongst water users and between them and the administrative and technical staff of the organization, and finally the failure of an agreement concerning the payment of the water tariffs.

    The present management attitude clearly shows that the management only provides irrigation water without questioning whether the water contributes to the success of the production system of the farmers. The present situation is a result of the growing discrepancy in interests of the two parties: the organization is focused on the provision of irrigation water that is paid through a tariff and the farmers expect actions from the organization that will support them in the development of projects that will improve their standard of living.

    This management approach and some external factors caused several problems on, for instance the interceptor canal, the water quality, salinization processes, maintenance of the infrastructure, and development projects with international cooperation for the modernization of the district. The present crisis can be seen from the poor conditions of ASORUT, especially in the technical, economic, social, environmental, and institutional parts of the organization.

    The operation of the district is nowadays much more complex and the water supply has been affected by changes in the cropping pattern, by lack of irrigation schedules and cropping plans. The farmers decide themselves about the crops, the planting date and the moment that they request irrigation water. Sugar cane covers one-third of the area and requires much more water than the traditional crops. Modern agriculture practices use fruit trees that require a water supply with short irrigation intervals.

    The major environmental problems are related to the water quality. The domestic and industrial waste-water and the deforestation of the adjacent catchment areas are affecting the water quality of the irrigation canals and the Cauca River. At several places the salinization process is intensified by the reuse of drainage water, inefficient irrigation practices, lack of a drainage system at farm level, and salinization caused by groundwater.

    One factor that seriously influences the critical situation is the fact that there are two types of farmers in the area, namely the small and middle farmers and the large ones. Their minimal economic resources together with a low technology and small land area, the small and middle farmers can not, like the large ones, introduce and grow crops with a high profitability, like fruit crops. This has caused a lot of tension and disagreement between the two groups.

    Sustainable Management for the RUT Irrigation District; implementation of a conceptual framework

    An analytical framework for integrated water resources management has been used to formulate a well developed proposal for an integrated and sustainable management plan for ASORUT. The assessment of the present situation, the formulation of this management plan and the required interventions have been derived from interviews with farmers, administrative, technical, and field personnel from ASORUT, representatives of the municipalities and representatives of public and private institutions closely related to the land improvement sector.

    Proposals for integrated and sustainable management scenarios will be based on the potential internal and external factors of the district and their influence on the management process. Two scenarios can be developed for the district, namely a Direct Governmental Intervention Scenario and a Participatory and Communal Approach: a New Role for ASORUT.

    Both scenarios start from the current critical condition, but the first scenario is based upon the assumption of a continuous deterioration due to the present low management capability to produce the necessary changes that can lead to a gradual recovery. Inegative factors willcontinue to build up, for instance an increase in non-profitable agricultural practices resulting in a low willingness and capability of the farmers to pay the water fees; an increase of outstanding bills as the water users are not able to pay for the services resulting in a decreasing financial capacity of the organization. Other factors include changes in land use, especially the expansion of extensive crops like sugar cane and of other, non-agricultural uses; changes in the land tenure and lack of incentives for investments, especially in cash crops, agro-industry and marketing; increase of the presence of illegal groups that will cause unemployment and poverty. In this scenario ASORUT will have a very low management capability and its credibility will be at a very low level for the farmers, government and supporting public and private entities and that will result in a serious isolation of the organization within the national, regional and local context. In this scenario the gap between the two groups of farmers will not be bridged, but even deepened by the large difference in socio-economic conditions.

    This situation will form the start for the next phase of this scenario in which the government takes over the total control of the district and will undertake the necessary actions for a new organizational model. In this case the government may decide for a concession model, which has recently been considered during the changes of the legal framework for the land improvement sector (August, 2005). According to the law a Concession Contract contains the provision, operation, exploitation, organization and partial or total management of a public service; or the construction, exploitation and partial or total conservation of a work or good for the public use or service. It also includes all the necessary activities to be developed by the concessionaire for the appropriate provision or functioning of the work or public service and the remuneration for the control and care of the work or service by the concessionary entity is arranged by rights, tariffs, tax, and valuation, amongst others.

    This scenario will result in a management organization that will concentrate its services as irrigation water supplier on the large farmers, which present a strong socio-economic entity due to their most profitable agriculture practices. This management model will result in economic, financial and technical sustainability in the short and middle term, but its social sustainability will be seriously endangered due to the deepening of the differences between the small-middle farmers and large ones; the expected benefits will result in social inequalities as the large farmers will be strengthened and the small-middle ones will be excluded from any benefit.

    In the second scenario the community consisting of the water users in the district will play the main role; the water users association as representative of the users will head the development process. The fear of the community that the government could give the system management to another private organization forms the main incentive to change the present management situation without the interference of the government. The development process towards a sustainable management will follow an integral and participatory approach involving all the internal and external actors: namely the farmers as first beneficiaries; the technical and administrative staff; representatives of each municipality located in the influence area of the irrigation district; the land improvement sector; other supporting private and public entities. As a legal organization, ASORUT will act on behalf of all the farmers before public and private institutions in order to develop programs in a mutual way. Within this participatory scenario the organization will have a clear statement about its mission, which is aimed at the improvement of the quality of life of the farmers through a sound management of the district under principles of equity, competitiveness, sustainability and multi-functionality in line with the legal framework established by the government. This means that the activities will have to be broad and be focused on improved socio-economic conditions and living standard of its beneficiaries in an integrated and sustainable way.

    In this scenario ASORUT will have a well developed ability to formulate, plan and implement development-coherent programs for the short, medium, and long term. These programs will include socio-economic, technical, and environmental components and will be based on an integral, participative, and communal approach, meaning the participation of all the directly and indirectly involved actors. The programs will be based upon the promotion and practice of irrigated agriculture under criteria of profitability, efficiency, competitiveness, and sustainability, and at the same time the protection and conservation of the natural resources.

    Some major expectations from the implementation of this participatory and communal approach might include:        active participation and an improved sense of belonging of the farmer's side due to a better standard of living as a result of new, successful commercial projects; the farmers will have a better opinion concerning the organization; they will see that the organization pursues the well-being of all of them and as a consequence conflicts will reduce; commercial agriculture and corresponding business will reduce poverty and unemployment and increase the standard of living and will create a favourable environment for the conservation of the natural resources; the management capability of the organization will get stronger resulting in an efficient water supply to all the farmers, but also in the formulation and implementation of profitable agricultural projects; the community in the district will obtain more authority in a gradual way and will develop a mutual decision-making process in which the major differences between the two groups of farmers can be brought down resulting in a harmonic development; ASORUT will be recognized at local, regional and national level by all the public and private entities in view of its sound management and it will have a high ability for inter-institutional relationships; the physical infrastructure (pumping stations and other installations) will be used in a more efficient way and ASORUT will support and enhance the marketing of agricultural products.

    As a final conclusion it can be said that this scenario is the most suitable one for the district, the water users and farmers in view an integrated and sustainable management. Its implementation and successful development will create new conditions that will empower the community and allow them to participate in an active way in the decision-making process, while they take their responsibilities as they are the central actors for the necessary change processes.

    Physical and non-physical interventions considering the new management scenario

    Before the implementation of the new management scenario it is important that the present physical infrastructure of the RUT Irrigation District is brought to a higher level. The most important interventions are related to the pumping stations together with the implementation of new sand traps; improvement of the marginal irrigation canal, conveyance canal, canal 1.0 and the interceptor canal to reduce seepage losses and costs for maintenance; the modernization of three water level control structures in the interceptor canal to assure a correct operation of the canal. The new management would have to pay special attention to a proper water management that will result in a more efficient water use, a proper use of the hydraulic infrastructure and a correct operation of the pumping stations in order to reduce the high energy costs. In this way the management will regain its authority.

    The interventions from an environmental point of view should be mainly focussed on the water quality, the proper disposal of solid waste, the protection and conservation of the micro-watersheds, the control of the salinization process, and the formulation of an elaborated plan for the environmental management. The operational function of the new organization will have to focus on the use, reuse and control of water for irrigation in order to fulfil the specific needs and demands of the farmers.

    One of the major problems to be solved by the new management concerns the financing of the administration, operation and maintenance activities. That financing should come from the establishment of a new tariff structure. Discussions with the farmers have shown that they are willing to pay for the service that supplies irrigation water, because until now agriculture is for them the only profitable economic activity. The tariff would have to be supported by incentives for an efficient water use and reuse; and fines by an inefficient use of irrigation water. Activities to improve the economic condition of the farmers will help to increase their willingness to pay for water, especially in the case of the small and middle farmers.

    ASORUT needs to consider other possibilities for additional economic resources different to those coming from water fees. On the short term new financial resources can be obtained from the participation in the identification and implementation of agricultural production projects; from obtaining new credit lines; provision of technical services for the development of agricultural activities; and marketing of agricultural products. On the mid- and long-term, ASORUT can obtain more economic income from other, but parallel money-making projects, like agro-tourism, small rural enterprises, agro-industrial processing; and training programs for other irrigation districts.

    Productive agriculture in the future would have to be based on to the existing natural conditions within the area. Some of the crops, like grains, fruits, vegetables, cotton and grass offer good perspectives in view of international markets (fruits and vegetables) and can get some added value through agro-industrial processes within the area. Corn for example offers good possibilities to meet the local and national demand and can provide raw material for the national industry. Sugar cane forms the basis for an important production chain in the Valle del Cauca Department, but the crop is not very suitable for the prevailing conditions of ASORUT and it had a very negative impact on the physical infrastructure.

    ASORUT would have to promote privately negotiated future contracts, especially for small and middle farmers that will assure favourable selling prices, volume and quality of the agricultural products. These contracts can be for example with large department stores, large farmers who need a certain production volume and with the agro-processing industry or the National Agricultural Stock Exchange.

    The new ASORUT needs to try to recover and strengthen the sense of togetherness of the farmers by adapting objectives of the organization that are in line with the interests and expectations of the farmers, who for instance expect the development of profitable agricultural practices and the improvement of their standard of living in an efficient and equitable way. Transparency, accountability, clear actions, administrative efficiency, and equity are requirements demanded by farmers to create confidence in the organization.

    Expectation for a New Role for ASORUT

    A process that clearly reflected a bottom-up approach was followed in the framework developed as part of this research. The different stakeholders and other actors involved got the opportunity to present their views and ideas in several participatory workshops and direct discussions. In this way, the key factors for the present critical situation of ASORUT, the wishes and expectations of the farmers and other actors, and the required interventions have been identified.

    Two scenarios for the management of ASORUT have been developed and after a thorough analysis, one model, namely the "Scenario for a Participatory and Communal Approach: a New Role for ASORUT" is considered as the most suitable one in view of an integrated and sustainable management of the RUT Irrigation District.

    The transition stage will start from the present low organization level of ASORUT that is a result of different socio-economic and political events during the lifetime of the organization and for which ASORUT had not yet the adequate answers and adaptation capability to tackle the new circumstances and acquired responsibilities after the transfer of the irrigation management. At this moment, ASORUT suffers under a process of destruction at different levels that will practically end in a state of total collapse of the organization. This meagre state of the organization is reflected for instance in the poor socio-economic condition of the farmers, especially the small and middle ones, in the poor management capability of the organization and in a low credibility in the eyes of the farmers and the society at large.

    The questions to be answered are: how is it possible to implement the selected scenario under the current situation of ASORUT; how long will it take to arrive at the desired management condition and what are the requirements for the envisaged development? A vision of the near future under the new management model shows that ASORUT will be an organization based on equity, efficiency, sustainability and competitive criteria with the mission to promote the welfare of all the beneficiaries (farmers), to improve their socio-economic conditions through profitable agricultural practices and to be involved in all the stages of the production chain: production, post-harvest management, added value process (agro-industry), and marketing.

    Therefore, the stakeholders of ASORUT and the different actors involved have to make very vital and wide-reaching decisions on the short term to safeguard the organization and the physical infrastructure. In the presented scenario the current situation is considered as a "transition stage", which bridges the present degenerating organization and the new one that will be characterized by a dynamic behaviour and a capability to interpret and satisfy the wishes of the stakeholders in view of the sought improvement of their socio-economic living conditions. Moreover, this dynamic attitude of the new organization will be able to maintain and develop stable and lasting contacts with supporting public and private organizations in the land improvement sector, and will take advantage of all the available opportunities for further development as they are offered within the new management framework and the recent government policy for the land improvement. Passing from the current status (transition stage) to the desired condition will take considerable time, which is based on the fact that the ongoing deterioration process of the organization started a long time ago. The formulation and implementation of some small productive agricultural pilot projects that will involve small groups of small and middle farmers will be used as a strategic approach.

    This knowledge is based upon successful experiences in the Zulia Irrigation District, in the north-east of Colombia, which has now reached a degree of sustainable development where the farmers perform the central role, meaning that they lead and determine the development policy of the organization. In order to embark on and to reach the new management conditions for ASORUT the key actors will have to play an important role. The Board of Directors would have to include representatives of the farmer's community along with the Government Agency represented by the Departmental Agriculture Secretary. Other supporting public and private entities will join their resources and efforts in a concerted way to contribute to the final realization of the new management model.
    La Cordillera Occidental Colombiana. Transecto Tatamá
    Hammen, T. van der; Rangel, J.O. ; Cleef, A.M. - \ 2005
    Berlin : J. Cramer (Studies on tropical Andean ecosystems vol. 6) - ISBN 9783443500283 - 956
    ecosystemen - tropen - vegetatie - bossen - natuurbescherming - colombia - andes - ecosystems - tropics - vegetation - forests - nature conservation - colombia - andes
    This volume 6 of the series Studies on Tropical Andean Ecosystems, contains the results of the Colombian Western Cordillera around latitude 5° N. The fieldwork was realized in 1983. The transect consists of two parts, the first between 500 m and 2150 m altitude located slightly South of 5° N, at the latitude of San José del Palmar, and the other slightly North of 5° N, at the latitude of Santuario and the Tatamá massif, between 2150 and 4200 m altitude. The total transect was therefore named: "The Tatamá transect".
    Successional position of dry Andean dwarf forest species as a basis for restoration trials
    Groenendijk, J.P. ; Duivenvoorden, J.F. ; Cleef, A.M. ; Rietman, N. - \ 2005
    Plant Ecology 181 (2005)2. - ISSN 1385-0237 - p. 243 - 253.
    exotic tree plantations - caribbean pine - rain-forest - regeneration - colombia - vegetation
    The successional affinity of nine woody species was inferred from the structure, diversity and disturbance history of the vegetation where these occurred. This was done in order to obtain a basis for a restoration experiment, currently in execution, in the dry Andean dwarf forest zone on the edge of the High Plain of Bogotá (Colombia), at 2600-2950 m.a.s.l. We laid out 101 relevees in grassland and shrubland types in different stages of recovery, and in relatively little disturbed endemic Condalia thomasiana dwarf forest. The disturbance history of sites over the last ~60 years was inferred from aerial photograph series (1941-1991). CCA and logistic regression were applied to relate species composition to diversity, environment and disturbance history. All species showed a preference for certain structural groups. Also, a clear relation between species occurrence and vegetation diversity was found. Baccharis macrantha, and Dalea coerulea appeared relatively tolerant to grazing, while the remaining seven species reacted negatively. Soil clay content, base availability and organic carbon content was also an important factor for occurrence of each species. Invasion of grasslands by woody species is pioneered by Baccharis macrantha and followed by Dodonaea viscosa. Dalea coerulea was predominantly found on truncated clayey soils, which will probably not support Condalia dwarf forest. The hypothesized classification of the nine planted species to either pioneers or late-successional was fine-tuned. This exploratory study will be of use in the set-up of future succession-based restoration experiments, and for converting exotics afforestations to natural vegetation
    A new method of measuring the adoption of soil conservation practices : theory and applications
    Castaño, J. ; Meulenberg, M.T.G. ; Tilburg, A. van - \ 2002
    Netherlands Journal of Agricultural Science 50 (2002)1. - ISSN 0028-2928 - p. 95 - 115.
    bodembescherming - duurzaamheid (sustainability) - bodembeheer - clusteranalyse - colombia - innovaties - adaptatie - meting - soil conservation - sustainability - soil management - innovations - adaptation - measurement - cluster analysis - colombia
    This paper presents a new methodology for measuring the adoption of sustainable agricultural practices that attempts to integrate positive features of earlier approaches. It measures the degree of sustainability observed by the farmer and, at the same time, is straightforward and efficient in field-by-field appraisals. The methodology proposed starts with the identification of all available soil conservation practices in the area. The practices are then grouped into activity categories and are ranked within each category on the basis of their expected soil conservation effect on the plot system. The resulting ranking system is applied to each plot included in the analysis. Non-linear principal component analysis is carried out on the plot rankings to extract a limited number of major metric components. The method is applied to the Cabuyal watershed in Colombia. The analysis shows that soil management strategies of Cabuyal farmers consist of different combinations of basic soil conservation practices: soil disturbance control, soil protection practices and run-off control. A cluster analysis of the plot scores on these three combinations revealed that the different strategies of soil management are related to the institutional, economic, physical and personal- social factors affecting farms and farmers. The results from the cluster analysis show the usefulness of the proposed methodology for policy purposes
    Interactive design of farm conversion : linking agricultural research and farmer learning for sustainable small scale horticulture production in Colombia
    Lee, R.A. - \ 2002
    Wageningen University. Promotor(en): N.G. Röling; E.A. Goewie. - S.l. : S.n. - ISBN 9789058087492 - 293
    tuinbouw - landbouwproductie - kleine landbouwbedrijven - conversie - duurzaamheid (sustainability) - landbouwkundig onderzoek - boeren - voorlichting - colombia - agrarische bedrijfsvoering - landbouwvoorlichting - horticulture - agricultural production - small farms - conversion - sustainability - agricultural research - farmers - extension - farm management - colombia - agricultural extension

    Key words: interactive conversion design / vegetable production / small farms / sustainable farming / Colombia / learning processes / facilitation / agricultural research methods

    Economic and ecological pressure on small farmer production in Colombia has increased since the globalisation of trade in the early 1990s. Although the climate allows for year-round production, the farmers live precariously due to a high dependence on external inputs, poor access to different sources of information on production technology and lack of control over market prices. Mechanisms are required to help these producers find alternatives to stabilise their income while reducing the negative effect their farming practices have had on the environment.

    This book describes an innovative situation where agricultural research provides a viable methodology for moving towards sustainable agriculture involving new (technical) learning for the farmers and parallel capacity building to ensure long lasting effects of these efforts, at both farm and landscape level, using a case study approach. With the European prototyping as a starting point, a methodology for farm conversion is designed interactively with the farmers to ensure appropriateness to their situation. It is then applied by them using, and in some cases verifying, organic, botanical and biological management strategies based on scientific research. It looks at how conditions for using biological control at the farm level can be created at the landscape level. It looks at building a marketing strategy among small farmers. And it addresses the issue of replicability.

    Emerging from the facilitation of the farmer learning process came a sequence of coherent and novel research activities designed to generate farmer learning: understand the context, implement participatory diagnostic research to anchor the work in real problems, encourage the creation of a learning platform, interactively (with farmers) design a system based on the fanners' priorities that is effective at the farm level, and that is acceptable to fanners, identify and test science-based applicable technologies at the farm level, scale up this system from the farm to higher system levels, and ensure long-term project impact and farming community autonomy by providing the tools for accessing new information and training local facilitators.


    By studying the interface between the farmer learning pathway and the set of research activities involved in its facilitation, it became apparent that the farmers learning pathway is divided up into four phases. These are: 1. participatory diagnosis and the beginning of the creation of a learning platform, 2. improvement of production at farm level due to better technical knowledge leads to the realization of the importance of working together as a community, 3. this in turn leads to the search for solutions on a larger scale as a tool for regional development, and 4. building the capacity of the farmers to stand on their own. Each phase is related to the progress made by the farmers throughout the research based on accomplishments in the three dimensions of the development project: technical know-how for appropriate farm management, the creation of a cooperating group of farmers, and long-term sustainability through autonomy and self-reliance.
    Polarimetric data for tropical forest monitoring : studies at the Colombian Amazon
    Quiñones Fernández, M. - \ 2002
    Wageningen University. Promotor(en): R.A. Feddes; D.H. Hoekman. - Wageningen : Tropenbos International - ISBN 9789058087508 - 184
    tropische bossen - monitoring - remote sensing - polarimetrie - radar - cartografie - ontbossing - biomassa - amazonia - colombia - tropical forests - monitoring - remote sensing - polarimetry - radar - mapping - deforestation - biomass - amazonia - colombia


    An urgent need exists for accurate data on the actual tropical forest extent, deforestation, forest structure, regeneration and diversity. The availability of accurate land cover maps and tropical forest type maps, and the possibility to update these maps frequently, is of great importance for the development and success of monitoring systems. For areas like the Amazon the use of optical remote sensing systems as the source of information, is impeded by the permanent presence of clouds that affect the interpretation and the accuracy of the algorithms for classification and map production. The capabilities of radar systems to acquire cloud free images and the penetration of the radar waves into the forest canopy make radar systems suitable for monitoring activities and provide additional and complementary data to optical remote sensing systems. Information regarding forest structure, forest biomass, and vegetation cover and flooding can be associated with radar images because of the typical wave-object interaction properties of the radar systems.

    In this thesis new algorithms for the classification of radar images and the production of accurate maps are presented. The production of specific maps is studied by applying the developed algorithms to two different study areas in the Colombian Amazon. The first site, San José del Guaviare, is a colonisation area with active deforestation activities and dynamic land cover change. The second area is a pristine natural forest with high diversity of landscapes.

    A detailed statistical description of the polarimetric AirSAR data is made in terms of backscatter (gamma values), polarimetric phase difference and polarimetric correlation. This approach allows a better interpretation of physical backscatter mechanisms important for interpretation of images in relation to ground parameters. Theoretical cumulative probability density distributions (pdf) are used to describe the mean field values and the standard deviation for a class. A Gausian distribution is used to describe the field average gamma values; a circular Gausian distribution is used to describe the field average HH-VV phase difference and a Beta distribution is used to described the field average HH-VV phase correlation. The accuracy of the estimation of the field-averaged values depends on the level of speckle, i.e. number of independent looks. This effect is included in the calculation of the pdf's and therefore can be simulated.

    For the Guaviare site the classification algorithm is used to assess the AirSAR data in the production of a land cover type map. Classification accuracies are calculated for different combinations of bands and level of speckle. An accuracy of 98.7% was calculated for a map when combining L-HV and P-RR polarisations. Confusion between classes are studied to evaluate the use of radar bands for monitoring activities, e.g. loss of forest or detection of new deforested areas. In addition a biomass map is created by using the empirical relationship between the combination of the same radar bands and the biomass estimations from 28 plots as measured in the field. The agreement of the biomass map with the land cover map is used to evaluate the biomass classification.

    For the Araracuara site the classification algorithm is used to assess the use of polarimetric data for forest structural type mapping and indirect forest biophysical characterisation. 23 field-measured plots used for forest structural characterisation are used to assess the accuracy of the classification. A new SAR derived legend is more suitable for the SAR map allowing better physical interpretation of results. A method based on iterated conditional modes is introduced to create maps from the classified radar images, increasing in most of the cases the accuracy of the classification. The structural type map with 15 classes can be classified with accuracies ranging from 68% to 94% depending on the classification and the mapping approach. The relationship between forest structure and polarimetric signal properties is studied in detail by using a new decomposition of polarimetric coherence, based on a simple physical description of the wave-object interactions. The accuracy of the complex coherence is described using the complex Wishart distribution. In addition for the same area, a biomass map is created using the previous structural type characterisation as the basis for the classification, overcoming problems as the well know radar signal saturation.

    The possibilities and restrictions of creating biomass maps with AirSAR polarimetric images are deeply investigated. Two different approaches are proposed depending on the terrain conditions. A theoretical exploration on the physical limits for radar biomass inversion is made by using a new interface model, called LIFEFORM that describes the layered tropical forest in terms of scatterers. The UTARTCAN scattering model is used to analyse the effect of flooding, forest structure and terrain roughness in the biomass inversion.

    Biological control of whitefly on greenhouse tomato in Colombia: Encarsia formosa or Amitus fuscipennis?
    Vis, R.M.J. De - \ 2001
    Wageningen University. Promotor(en): J.C. van Lenteren. - S.l. : S.n. - ISBN 9789058085214 - 166
    trialeurodes vaporariorum - organismen ingezet bij biologische bestrijding - encarsia formosa - amitus - insectenplagen - tomaten - solanum lycopersicum - teelt onder bescherming - colombia - aleyrodidae - trialeurodes vaporariorum - biological control agents - encarsia formosa - amitus - insect pests - aleyrodidae - tomatoes - solanum lycopersicum - protected cultivation - colombia
    In Colombia, biological control of pests in greenhouse crops is only applied on a very limited scale in ornamentals and as yet non-existent in greenhouse vegetables. Greenhouse production of vegetables - mostly tomatoes- is a recent development, as a result of the high losses of field production due to pests and diseases. Pest spectra in those production systems vary greatly with altitude, being much broader in the intermediate climate zones (altitude 1800-2000) than in the cold climate zones such as the Bogota Plateau (altitude 2660 m). The most important pest in greenhouses situated on the Bogota Plateau is the greenhouse whitefly, Trialeurodes vaporariorum . In greenhouses where experimentally no pesticides are applied, aphid and leafminer pests are controlled beneath economic damage thresholds by naturally occurring parasitoids, with the exception of greenhouse whitefly. Therefore, with a biological control system for T vaporariorum , tomato production without insecticides should be possible. In this thesis I evaluate two natural enemies for the biological control of T vaporariorum : the introduced parasitoid Encarsia formosa and the native parasitoid Amitus fuscipenni s.
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