CONSERVATION TILLAGE RELATED TO TROPICAL FOREST ISSUES
Patricia Negreros-Castillo1, Edgar Morales-Ortiz2, & Emily Mize3
1Iowa
State University, Forestry Department. Ames Iowa.
assistant, Felipe C. P. Quintana Roo, Mexico.
3Undergraduate student, Grinnell College
2Research
Corresponding author
Patricia Negreros-Castillo, Iowa State University, Forestry Department, Ames, Iowa 50011, Tel (515) 2945708, Fax (515) 294-2995, pnc@iastate.edu
Key words: Mexico, secondary vegetation, slash and burn, multistrata
Summary
Conservation of natural resources in tropical regions tends to be more complicated
than in temperate regions. In many cases, the use and management of tropical forest
has resulted in the creation of large mosaics of secondary vegetation. Generally,
secondary vegetation is considered of low economic value from the agricultural and
forestry point of view. Secondary vegetation, however, has many currently untapped
potential uses if allowed to reach maturity. One possibility for lengthening the fallow
period is to find a way for farmers to cultivate some of their crops without completely
clearing the forests. Thus, improving farming systems methods and productivity of crop
land might be an approach to take advantage of this vegetation and maximize its
potential. This paper is focused on the description of a multistrata agroforestry system
designed to take advantage of secondary vegetation and maximize its potential. The
system is known as the “Kampocolche system” (KS), a multi-strata agroforestry system
developed with the input of local farmers and scientists.
Introduction
Conservation of natural resources in tropical regions tends to be more complicated
than in temperate regions. Tropical ecosystems are more complex and less is known
about them than temperate ecosystems. Too often development projects in tropical
Mexico require the clearing of large forested areas to establish monoculture
agriculture or cattle grazing projects [Sere and Lovell, 1992]. Many of these projects,
however, have been unsuccessful and abandoned. Frequently, farmers use young
secondary vegetation (not older than 12 years) for unproductive slash and burn
agriculture. Consequently, the use and management of tropical forests has resulted in
the creation of large mosaics of secondary forest. In Mexico from 18 to 24 million ha of
forest are considered disturbed or secondary forests [Cairns et al 1995, Masera et al
1992]. In general, secondary vegetation is considered of low economic value from
the agricultural and forestry point of view. Secondary vegetation, however, has many
currently untapped potential uses if allowed to reach maturity. One possibility to
lengthen the fallow period is to find a way for farmers to cultivate some of their crops
without completely clearing the forests. Thus, improving farming systems methods and
productivity of crop land might be an approach to take advantage of this vegetation
and maximize its potential. This paper is focused on the description of a multistrata
agroforestry system designed to take advantage of secondary vegetation and
maximize its potential. The system is known as the “Kampocolche system” (KS), a multistrata agroforestry system developed with the input of local farmers and scientists.
Materials and Methods
Site description
Quintana Roo is one of three Mexican states in the Yucatan peninsula (south
eastern part of Mexico). The annual rainfall is between 1000 mm and 1350 mm,
distributed unevenly with a 3-4 month dry period, and average annual temperatures
of 25.9° [Tamayo, 1981]. The composition of the forest is the result of the precipitation
regime, soil, hurricanes, fires, and the agricultural activities that have dominated the
land since remote times [Gómez-Pompa et al., 1987]. Tropical forests in Quintana Roo
are classified as tropical dry forest formation [Holdridge, 1947]. This study was carried
out at Kampocolche, a Mayan community in central Quintana Roo, Mexico.
Kampocolche is one of 20 “ejidos” (communities) that belong to the Mayan Forestry
Community Organization of Quintana Roo. Kampocolche controls around 8000 ha of
very disturbed forest. Currently the only product the farmers harvest for commercial
purposes is poles used in rustic construction for nearby tourist centers. Approximately
115 families form the community, and their major activity is slash and burn agriculture.
Methods
The Kampocolche system is the result of a research project initiated in 1994
[Negreros-Castillo, 1994]. The main objective of the project focuses on tapping the
potential uses of secondary vegetation through the application of agroforestry and
agroecological principles. The project comprises the following stages:
2
1) Study of the species composition of secondary vegetation in three different types of
soil and four different ages (2, 5, 8, and 12 years old). Carried out in 1994 [NegrerosCastillo et al., 1995]
2) Study of the agricultural crops suitable for cultivation at different light levels as a
multistrata agroforesty system develops. Carried out during the Fall of 1997 [De
Clerck and Negreros-Castillo, 1998].
3) Study of 10 very diverse and managed homegardens as models to develop
agroforestry systems from secondary vegetation. Carried out during the Fall of 1997
[Morales, 1998].
4) Nutritional value of some suitable crops for multistrata agroforestry systems. Carried
out during the spring of 1998 [Barrera & Negreros-Castillo, 1998].
5) Design and establishment of experimental multistrata agroforestry system. This stage
of the project was initiated in January of 1998.
Development of the Kampocolche system
By applying agroforesty and agroecology principles [Gliessman et al., 1981;
Torquebiau, 1992; Caron, 1995] and using the information obtained in stages one to
four, a first design was developed. The first design was presented to the community
and 5 farmers volunteered to participate in the research. The system was then
explained in more detail and depth to these farmers. With the insightful input of
farmers the original design was modified and a new one emerged (Fig. 1). Because
the system was established in and with the collaboration of farmers from
Kampocolche, it was named after the town’s name.
Five repetitions of the
Kampocolche system were established in March of 1998. The chosen sites are in an
area of community land that was used for a cattle-grazing project from around 1980
until 1985. In 1980, 400 hectares of forest were cleared for cattle production. The
project failed, and the land was abandoned in 1988. The land soon became overrun
with secondary vegetation.
Therefore, the secondary vegetation used in this
experiment is 10-12 years old.
Results
The Kampocolche system is a multistrata agroforestry system designed to take
advantage of secondary vegetation and maximize its potential. The system combines
useful trees found in the secondary vegetation with crops and plants beneficial to the
producers. The crops are harvested at different times during the year and are able to
grow under different light conditions. The dimensions of the Kampolcolche system are
70x70 m. The system consists of four concentric areas of different sizes (Fig. 1).
1. Center zone: Annual crops.
Annual crops in the open. Crops using a method developed in northern Yucatan
[Gordillo et al.; 1998], which allows for more years of cultivation than conventional
methods. By lengthening the amount of time the field is cultivated, this lessens the
need to rotate to a new field. The crop system uses chicken manure as a
3
fertilizer in the first year and legumes in later years. The average production of corn
from the five plots was 3.5 ton hectare compared with 0.5 ton per hectare obtained in
the traditional slash and burn system.
2. Zone 1: Fruit trees + crops.
Seven different native fruit tree species (3 plants by species) (Table 1) were
planted in a 5m wide strip around the center zone. The fruit tree seedlings have a
height of about 50 cm. Between them 10 plants of tomato and 9 plants of hot pepper
were planted.
4
Table 1. Fruit trees planted in the Kampocolche system.
Cayumito
Crisophyllum cainito L
Ciruela Tuxpana
Spondias lutea L.
Guanabana
Annona muricata L.
Mamey
Pouteria mammosa (L.)Cronq.
Saramuyo
Annona squamosa L.
Zapote
Manilkara zapota(L.)V.Royen
Anona
Annona reticulata L.
SAPOTACEAE
ANACEAE
ANNONACEAE
SAPOTACEAE
ANNONACEAE
SAPOTACEAE
ANNONACEAE
3) Zone 2: Secondary vegetation + crops.
Secondary vegetation--this section surrounds the central and second zones of
the plot. A quarter of the area (east) was thinned to plant six different types of crops
underneath (Table 2). In the coming years, all the area will be planted with crops
suitable for growing in this environment.
Table 2. Crops growing with secondary vegetation
Number Name
Scientific name
1
Chaya
Cnidoscolus chayamansa
MC.Vaugh
2
Chile
Capsicum spp.
3
Makal volador Dioscorea bulbifera L.
4
Makal
Colocasia esculenta L.
5
Melocotón
Sicana odorifera Naud.
6
Nopal
Opuntia spp
Family
EUPHORVIACEAE
SOLANACEAE
DIOSCORACEAE
DIOSCORACEAE
CUCURVITACEAE
CACTATACEAE
4) Zone 3. Tree enrichment.
In a strip of 5m right at the edge of the plot, valuable timber tree species were
planted, at spacing of 5m (Table 3).
Table 3. High valuable timbers species planted around the plot.
Number Name
Scientific name
Family
1
Caoba/mahogany
Swietenia macrophylla K
Meleaceae
2
Cedro/Spanish cedar
Cedrela odorata
Meleaceae
2
Sricote
Cordia dodecandra
Boraginaceae
5
Monitoring system
Several measurements are being taken at a regular basis:
1.- Soil fertility before and after harvest
2.- Evaluation of the composition of the vegetation of the site
3.- Tree growth
4.- Crop production
5.- Labor (time and cost)
6.- Farmers understanding of the research and potential applications
Conclusions
Agroforestry systems are considered to function better than monocropping
systems. With their many interacting parts, they are more akin to nature and its
biodiversity. And, if the goal is to become more sustainable, modeling nature seems
to be the most desirable option. However, experiments like this one still need to be
carried out to determine the best way to imitate nature and also to provide
quantitative evidence that agroforestry systems work. Del Amo and Ramos (1993)
noted that we need more information on agroforestry systems to compete with the
amount of information available on plantations, cash crops, and cattle farming. That
is especially important in a country where the majority of farmers are poor and have a
family depending on them. They cannot afford to take risks and change their way of
farming without solid convincing evidence that the new system is more economical
and efficient for them. That is the beauty of the Kampocolche system. It incorporates
indigenous knowledge. It involves the people in the area because, ultimately, by
deciding whether or not to implement the system in the future, they will be the ones
judging whether or not the Kampocolche system is a success.
Bibliography
Barrera, S. and P. Negreros-Castillo.1998. Nutritional value of 12 crops suitable for
multistrata agroforestry systems. (Internal report) 5 pages.
Cairns, A. M. R. Dirzo, and F. Zadroga. 1995. Forests of Mexico. A diminishing
resource?. Journal of Forestry. July: 21-23.
Caron, CM. 1995. The role of nontimber tree products in household food procurement
strategies: Profile of a Sri-Lankan Village. Agroforestry Systems, V0032 N2,
1995, pp. 99-117
DeClerck, F. and P. Negreros-Castillo 1998. Crops suitable for the different
developmental stages of agroforesty systems in Quintana Roo, Mexico.
Sumbited to Agroforestry systems, July 1998.
Del Amo, R. S., and P.J. Ramos. 1993. Use and management of secondary
vegetation in a humid-tropical area. Agroforestry Systems, 21: 27-42.
Gliessman, S. R., Garcia, R.E., & Amador, M.A., 1981. The Ecological Basis for the
Application of Traditional Agricultural Technology in the Management of
Tropical
Agro-Ecosystems. Agro-Ecosystems, Vol 7, 173-185.
Gómez-Pompa, A., Flores, J.S. and Sousa, V., 1987. The "Pet Kot": A man made
6
tropical forest of the Maya. Interciencia, 12(1): 10-15.
Holdridge L. R., 1947. Determination of world plant formations from simple climatic
data. Science., 105(2727):367-368.
Masera, O., M.J. Ordoñez, and R. Dirzo. 1992. Carbon emissions and sequestration in
forests: Case studies from seven developing countries. Vol4: Mexico.
Berkeley, California: Environmental protection Agency, Climate change
Division and Lawrence Berkeley Laboratory, Energy and Environmental
Divisin. LBL-32665
Morales OE (1998). Evluation of the structure of composition of ten very diverse and
managed homegardens in tha Maya zone of Quintana Roo, Mexico.
Thesis to obtain BS in Forest Biology. Chetumal Forestry School (ITA16). 200
pp.
Negreros-Castillo P, M. Avila., M. Magaña-Monforte. 1995. Fallow vegetation in the
tropics: Opportunities for sustainable management through agroforestry.
Women in Natural Resources, December 1995. Vol. 17 (2): 32-35
Negreros-Castillo, Patricia. 1994. Aprovechamiento y manejo de la vegetacion
secundaria para el establecimiento de sistemas agroforestales
multiestrato. Research proposal for the Rockefeller Foundation of Mexico.
Pennington, T. D., and J. Sarukhán., 1968. Arboles Tropicales de México. INIF/FAO,
México. 413 pp.
Rzedowski, J., ad G. C. Rzedowski., 1989. Transisthmic Mexico (Campeche, Chiapas,
Quintana Roo, Tabasco and Yucatan). Pages 270-280 in D. G. Campbell
and H. D. Hammond, eds. Floristic Inventory of tropical countries. The
New York Botanical Garden, New York.
Sere, C and Lovell S. J. 1992. Livestock economy and forest destruction. In pp. 95-113
Development or destruction: the Conversion of Tropical Forest to Pasture
in Latin America. Eds. Theodore E. Downing, Susanna B. Hecht, Henry A.
Pearson, and Carmen Garcia-Downing. Boulder, CO: Westview Press,
Inc.
Sousa, S. M., and C. E. F. Cabrera, 1983. Flora de Quintana Roo. Pages in Listados
Florísticos de México. Instituto de Biologia, UNAM, México.
Tamayo, J. L., 1981. Geografía Moderna de México. Editorial Trillas, Mexico, D. F. 400
pp.
Torquebiau, E., 1992. Are tropical agroforestry homegardens sustainable? Ecosystems
and Environment. 41: 189-207
7
High value commercial timber species
N
Secondary vegetation
Papers and tomatoes
+ Fruit trees
5m
Annual
crops
Crops growing with secondary vegetation
20m
30m
70m
Central zone: Annual crops
Corn, squash, beans
Fertilizers: Chiken manure year 1
Green manure year 2
Compost
year 3 and following
Zone 2:. Secondary vegetation + crops
Cnidoscolus chayamansa MC.Vaugh
Capsicum spp.
Dioscorea bulbifera L.
Colocasia esculenta L.
Sicana odorifera Naud.
Opuntia spp
Zone 1: Fruit trees + crops
For 1998: papers + tomatoes + watermelon
Zone3: Tree enrichment.
Cordia dodecandra
Cedrela odorata
Swietenia macrophyla
*
Zapote
*
Saramullo
Ciruela
*
Secondary vegetation composition
Important species diam>10cm
Guanabana
Caimito
- P iscidia communis
- Caesalpinia gaumeri
- Lysiloma bahamensis
- Heliocarpus donnell-smithii
- Zuelania guidonia
-
*
Mamey
*
Anona
*
*
*
*
*
Figure 1. Lay out of the Kampocolche multistrata agroforestry system.
8