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Appendix I: field excursion to UAAAN experimental station, Noria de Guadalupe

The third day of the Workshop was given over to a field visit to this rangeland experiment station of the university, situated about 130 km south of Saltillo in the northeast of the State of Zacatecas. It is an area of 150 ha held in permanence by arrangement with the Ejido Noria de Guadalupe, whose members have provided labour and animals for station operations as needed. It is situated on the lower slopes of the San Tiburcio Watershed, an interior drainage basin of 1,500 km2, with mountains attaining 2,500 m and its lower levels at 1,700 - 1,900 m. Mean annual precipitation is 250 mm, 90 per cent of which comes in the summer and autumn (May-October), and recurrent drought follows the failure of seasonal rains. There is a moderate thermal regime (warmest month: July [mean 18.7 C]; coldest month: February [mean 8.5-C])

The natural vegetation consists of plant communities representative of the Chihuahuan Desert, growing on aridisols derived from sedimentary rocks, principally cretaceous limestones. The main communities have been described as:

- halophytic grasslands and shrubs, with grasses including Sporobolus airoides. Hilaria mutica, and Eragrostis obtusiflora, and shrubs such as Prosopis juliflora, Opuntia imbricata, and Koeberlina spinosa, particularly in the lowest areas;

- Larrea shrubland, extending over much of the basin, with Larrea tridentata and Flourensia cernua, and perennial grasses including Boutelous gracilis, B. curtipendula, and Setaria macrostachya;

- Opuntia-Yucca shrubland, covering a small area but important as a source of food, fodder and textile fibres, with Yucca filifera, Y. decipiens, Acacia farnesiana, Opuntia spp., and Parthenium incanum;

- Agave-Parthenium shrubland, with Agave lecheguilla, Foupiera splendens, and Euphorbia antisyphilitica, all of which have economic importance.

Land use in the area is primarily pastoral, as the climatic conditions impose considerable risk on cropping, under which yields are also low. There is extensive grazing of cattle, goats, and a few sheep, and domestic raising of chickens, rabbits, and pigs. Crops include mainly corn and beans, grown on small plots with better water relationships. Only 4 per cent of the land is irrigated. Agricultural activities are generally primitive. There is almost no mechanization of cultivation, and no access to improved seeds, fertilizers, and pesticides, whilst there is no selective breeding of livestock, which are poor producers of meat and milk.

Collective land tenure under the ejido system extends over 87 per cent of the area. However, within the ejido, land has been subdivided and allotted individually, and only the grazing lands are exploited communally. This has resulted in overgrazing, as the animals are individually owned s by only a few ejido members who try to maximize their benefits without regard to carrying capacities. Of the individual farming plots, 80 per cent are between 1 and 5 ha, 14 per cent between 5 and 10 ha, and only 6 per cent are larger than 10 ha.

Approximately 4,000 people live in the area, dispersed in numerous small settlements. Road access is poor, and even impossible when it rains. This is only one part of a deficient infrastructure, extending from transport and communications to drinking water, electricity, and sanitary, health, and educational services. Educational standards are correspondingly low. In a sample taken from seven ejidos in the region, 44 per cent of the men had had no schooling at all, and only 5 per cent had finished primary schooling. The majority of houses in the ejidos had only one or two rooms, with four to five persons per room. Tools and implements were few, as were improvements such as watering points and fences.

A secondary source of income for the peasants is the gathering and partial processing of plants of economic value: agave and yucca for fibre, Euphorbia antisyphilitica for wax, and guayule (Parthenium argentatum) for natural rubber. It is through such activities that the peasants survive during droughts.

The university has been working in the area since 1972, and since 1975 the operations have been under the control of the Department of Renewable Natural Resources. Dr Nava and his colleagues demonstrated some of their work to the participants. The fundamental objectives of the work have been set out as follows:

Natural Ecosystems

- to study the natural ecosystems and their functioning in relation to the natural environment;

- to study ecological successions within the natural ecosystems due to differing pressure of human usage, and to quantify such changes over time.


- to analyse the productivity of seasonal cropping and the influence of different systems of management;

- to study the productivity of reseeded rangelands, and of different forage crops.

Ecosystem Modification

- to generate local technologies through which the productivity of certain types of low yielding ecosystems can be increased;

- to establish principles to integrate the areas of managed ecosystems within a scheme of multiple resource use for maximum production;

- to define techniques to allow the transformation of the natural and managed ecosystems using means which generate employment for the rural work force;

- to compare the effectiveness and ecological costs of operation and management of the various ecotypes.

Ecosystem Functioning

- to calculate the response of the ecosystems to variations in inputs such as water and mineral fertilizer.

To these ends initial activities were focused towards the recuperation and improvement of deteriorated rangelands, and on experiments with a variety of approaches, ranging from complete removal of vegetation and seeding or planting with useful species to transformation of the existing rangeland through the selective removal of unwanted species, such as Larrea spp. The general aim was to design systems of eco-transformation to bring about selective recovery of useful components of the natural vegetation, with low inputs of technology and capital and using labour that could be supplied by the eventual beneficiaries. On the visit, participants saw various stages in the manipulation of the rangelands and in the recovery of degraded rangeland, and the contrast with deterioration on adjacent land being subject to uncontrolled grazing.

During the last few years there had been increasing concern about the lack of impact of these and other research projects on the lives of people in the surrounding communities, with the result that there has been a shift from mainly ecological/agricultural perspectives to those that give greater weight to the integral development of rural communities. Recently, UAAAN hosted a seminar with staff of Colorado State University, from which recommendations for joint research activities included:

-design of a technology package suitable for areas with less than 500 mm rainfall. Such technology should be compatible with prevailing principles of ecosystem management and should have the promise of increasing production and raising incomes of small farmers;

-design of an organizational structure to implement this technology package, i.e., to transfer such technology to the level of the small farmer. It should have special concern for the co-ordination of all the agencies of implementation;

-active participation of small farmers in the project in all stages from design to implementation.

The proposed research, experimental, and extension activities are to be carried out in the San Tiburcio basin over a period of six years. It is planned to link this work with extension and the provision of credit and sundry services from other sources, to make it problem-oriented and multidisciplinary. The technology package will include dryland farming practices, range and livestock management systems, and the gathering and use of native plants. It is hoped that the project will establish principles and technology applicable to small farmers elsewhere in semi-arid Mexico, and that the experience in inter-organizational co-ordination will have relevance to other programmes which stress an integrated approach to rural development.

Following the tour of the station, participants paid a short visit to see conditions at a nearby farming settlement, seeing en route co-operative and State-supported schemes for commercial rabbit farming, which had failed, and an operating dairy.

On the return to Saltillo participants were shown field plots of guayule, and briefly visited an afforestation scheme on the slopes above the university.

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