Recultivation saves the Amazonian rain forest

Terra firme - the dry land - is what the Brazilians call those parts of the Amazon region which are not submerged by the flooding rivers and are mainly covered by evergreen tropical forest. These largely virgin rainforests have been experiencing intense pressure from many parties interested in land use, and devastating processes (farming, forestry systems as weIl as mining) have already been set in motion at many sites.

The process generally starts with new roads or other transport paths cut into the forest. They serve as a point of entry for a continuously growing number of settlers who want to open up new living space and cut down the vegetation. Usable timber may be taken out but the major fraction of the wood is bumed.

The areas cleared, used for agriculture or stock raising, are usually exhausted after three or four years and the yields become progressively smaller. The owners then abandon these fields and clear a further tract of forest as areplacement so that the destruction is spread further.

In those areas of the Amazon region, around large cities like Manaus, the landscape is already mainly characterised by anthropogenic influences. The original forest has disappeared except for small, unconnected residual areas. A large number of people live in this region today and their economic needs must be included in any proposed solutions if the latter are to have any chance of success. Due to the rapid decline of fertility in the soils of former agricultural areas, which were abandoned because of economic reasons, fallow can be found around all urban centers like Manaus.

Within the bilateral German- Brazilian program on Studies of Human Impacts on Forests and Floodplains in the Tropics (SHIFT), in the project ENV 23 ("Recultivation", see Google Earth 2° 52'53.34'' S ; 59° 50'40.09'' W), these fallow lying areas were re-cultivated in order to identify biotic and abiotic stabilizing factors for agro-ecologically equilibrated production systems. Furthermore, a viable method to install a sustainable plantation with minimised losses in the starting phase had to be demonstrated as a concrete, environmentally friendly option for long lasting agricultural use of tropical areas.

Summary of experimental results

The experimental polyculture systems installed as different planting systems with increasing complexity resulted in sustainable agriculture on degraded sites. The experimental area has been available to study several ecological and economical aspects for a variety of research groups of in total four SHIFT projects. Most important in the early installation phase of the experimental system was the consideration of the mycorrhizal technology and its demands to reach a quick ecological equilibration and positive economic balance. Fertilizer level, plant combination and interactions between plants were assessed qualitatively and quantitatively over a period of more than eight years. Compared to the monoculture, polyculture was more stable against pests and diseases of the crops. Inoculation with arbuscular mycorrhiza decreased plant loss after planting. One year after planting, the population of mycorrhizal spores on the experimental sites was very heterogeneous. The change of AMF spore type composition could be used as indicator for the ecological stabilization process. The externally produced and then introduced Glomus etunicatum inoculum was successfully substituted by other autochtonous fungi. Already in the transition phase, before a sustainable production phase was reached, the yields of Carica papaya and Manihot esculenta were commercially relevant. Four years after the installation, the system reached its production phase which was mainly based on Bactris gasipaes, Theobroma grandiflorum and Bixa orellana. Mycorrhizal treatment partially revealed higher yields, better growth and disease tolerance of crops. The vegetation was assessed in the experimental sites as well as in secondary and primary forest. The spontaneously growing secondary vegetation could be used as an indicator system for the assessment of prior land use and site quality. An extensive list of species was compiled. During the experimental period, the polyculture systems were proved to have a stable production due to adapted management procedures like mulching and methods of precision farming. The integrated plant management system could be recommended for the regional agriculture, particularly with regard to agro-ecological aspects (soil erosion, disease susceptibility, nutrient storage). Besides perennial crops, the planting systems provided potential farmers with annual crops for their subsistence. Due to the complexity of the planting systems, small holders will need a more thorough training than for the conventional subsistence systems.

Publications
  • Feldmann, F., da Silva jr., P. J., Lieberei, R., 2002: AMF Spore Community Composition at Natural and Agricultural Sites in Central Amazonia – a Long Term Study. In: Lieberei, R., Bianchi, H-K., Boehm, V., Reisdorff, C., (eds.), 2002: Neotropical Ecosystems, Proceedings of the German-Brazilian Workshop, Hamburg 2000. GKSS-Geesthacht; p. 669-682
  • Feldmann, F., Silva Jr., J.P. und A.V.R. Jayaratne, 1999: Nutzung der arbuskulären Mykorrhiza in Baumschulen der Tropen am Beispiel des Kautschukbaumes Hevea spp. Mitteilungen der Biologischen Bundesanstalt, 363, 83-92.
  • Feldmann, F., 1998: On „dry land“ in the Amazonian region: Recultivation of agricultural land. In: BMBF+T (Ed.): Research for the tropical forest, p. 44-46
  • Feldmann, F., 1998: Recultivation: New uses for old land. In: BMBF+T (Ed.): Research for the tropical forest, p. 46-53
  • Feldmann, F., 1998: On the benefits of native plants. In: BMBF+T (Ed.): Research for the tropical forest, p. 48-49
  • Feldmann, F., Idczak, E., Martins, G., Nunes, J., Gasparotto, L., Preisinger, H., Moraes, V.H.F., Lieberei, R., 1995: Recultivation of degraded, fallow lying areas in central Amazonia with equilibrated polycultures: Response of useful plants to inoculation with VA-mycorrhizal fungi . Angewandte Botanik, 69, 111-118
  • Feldmann, F., Idczak, E., Nunes, C.D.M., 1995: A importancia dos fungos micorrizicos no manejo de sistemas agricolas na Amazonia. In: Kanashiro,M, Parotta, J.A. (eds): Manejo e reabilitacao de areas degradadas e florestas secundarias na Amazonia; USDA, Puerto Rico, USA, S. 57-65
  • Feldmann, F., Müller, I., Weritz, J., Macedo, J.L.V., Idczak,E. , 1995: Isolamento, selecao e producao de fungos micorrizicos vesicular-arbusculares (FMVAs) e seu aplicacao em sistemas de policultivo. In: Kanashiro,M, Parotta, J.A. (eds): Manejo e reabilitacao de areas degradadas e florestas secundarias na Amazonia; USDA, Puerto Rico, USA, S. 66-71
  • Feldmann, F., Gasparotto, L., Preisinger ,H., Lieberei, R., 1995: Rekultivierung degradierter, brachliegender Monokulturflächen in ausgewogene Mischkulturflächen unter besonderer Berücksichtigung bodenbiologischer Faktoren. In: IAngBot Reports 111/112, 178-184
  • Feldmann, F., Gasparotto, L., Lieberei, R., Preisinger, H. , 1995: Utilizacao de areas abandonadas na Amazonia com policultivo de plantas perenes uteis<br /> In: Kanashiro,M, Parotta, J.A. (eds): Manejo e reabilitacao de areas degradadas e florestas secundarias na Amazonia; USDA, Puerto Rico, USA, S. 46-56
  • Feldmann, F., Lieberei, R., 1994: Vesicular-arbuscular mycorrhiza in rubber tree monocultures. Mycorrhiza News (New Delhi) 5 (4), S. 1-6
  • Feldmann, F., 1995: Auf dem „festen Land“ in Amazonien: Rekultivierung von Nutzflächen. In: BMBF+T (Hrsg): Forschung für den Regenwald, S. 44-53
  • Feldmann, F., Lieberei, R. 1994: Erfolgversprechende Rekultivierung brachliegender Flächen in Zentralamazonien. Universitäts-Pressedienst Hamburg, Abteilung Forschung; Mitteilungsblatt „Uni hh“ 01/94 26-27
  • Feldmann, F., 1994: Wenn der Regenwald zerstört ist, Journaille 7, Universität Hamburg, S. 7-10
  • Feldmann, F., Idczak, E. , 1994: Inoculum production of VA-mycorrhizal fungi for use in tropical nurseries<br /> In: Norris, J.R.; Read, D.J., Varma, A.K.. (eds.) :Techniques for mycorrhizal research, Academic Press, San Diego, S. 799-817
  • Feldmann, F., Gasparotto, L., Preisinger, H., Voß, K., Lieberei, R., 1994: Ökonomisches Potential von Nutzpflanzen nachhaltiger Mischkulturen Amazoniens<br /> In: Lieberei, R., Voß, K., Brügmann, C. (Hrsg.): "Tropische Nutzpflanzen", Hamburg, FRG, S. 62-69
  • Feldmann, F. , 1994: Mycorrhizal situation of native trees in the Brazilian tropical ecosystems Varzea, Igapo, and Terra firme. In: Lieberei, R., Voß, K., Brügmann, C. (Hrsg.): "Tropische Nutzpflanzen", Hamburg, FRG, S. 70-77
  • Idczak, E., Feldmann, F., 1994: Mykorrhizastatus von aufgelassenen Kautschukbaum-Plantagen des Amazonasgebietes nach Abbrennen und während der Rekultivierung. In: Lieberei, R., Voß, K., Brügmann, C. (Hrsg.): "Tropische Nutzpflanzen", Hamburg, FRG, S. 78-88
  • Lieberei, R. & Feldmann, F., 1993:DIE NUTZUNG MARGINALER STANDORTE IM REGENWALDGEBIET AMAZONIENS. Applied Botany Reports 5, 201-204
  • Feldmann, F. & Lieberei, R., 1992: Rekultivierung degradierter Monokulturflächen Amazoniens : I. Layout und Ziele des Projektes und II. Erste Ergebnisse; SHIFT Newsletters, BEO, Jülich
  • Feldmann, F., Idczak, E., 1992: Inoculumproduction of VAM fungi for use in tropical nurseries. In: Varma, A.K.; Norris, J.R.; Read, D.J. (eds.) : Methods in Microbiology 24: Experiments with Mycorrhizae, S. 339-357
  • Feldmann, F., Lieberei, R., 1992: Kulturmaßnahmen im Pflanzenbau des Kautschukbaumes und ihr Einfluß auf das Vorkommen von Mykorrhiza in Plantagen des Amazonasgebietes. Berichte des Institutes für Angewandte Botanik, 4, S. 67-87
  • Feldmann, F., Lieberei, R., 1991: Mycorrhiza induced changes in the defence metabolism correlated with enhanced leaf resistance against pathogens. Plant Physiol. (5), S. 874
  • Feldmann F., 1991: Die Mykorrhiza des Kautschukbaumes Hevea spec. Müell. Arg.: Vorkommen am Naturstandort, Auswirkung auf das Resistenzverhalten, Nutzung im Plantagenbau. Dissertation, TU Braunschweig, 1991
  • Lieberei, R., Junqueira, N.T.V., Feldmann, F., 1989: Integrated disease control in rubber plantations in South America. Proceedings of the '89 Integrated Pest Management, February 8-15, 1989, Bad Dürkheim, FRG, S. 445-456
  • Lieberei R., Feldmann, F., 1989: Physiological changes in roots colonized by vesicular-arbuscular mycorrhizal fungi. Agriculture, Ecosystems and Environment, 29, S. 251-255
  • Feldmann, F., Junqueira, N.T.V., Lieberei R., 1989: Utilization of vesicular-arbuscular mycorrhiza as a factor of integrated plant protection. Agriculture, Ecosystems and Environment, 29, S. 131-135
  • Lieberei, R., Feldmann, F., 1988: Mycorrhiza in cyanogenic plants. Plant Physiol. 86 (4), S. 879
  • Feldmann, F., 1987: Morphologische und physiologische Veränderungen in Hevea-Wurzeln im Zuge der Besiedelung durch bodenbürtige Pilze. Diplomarbeit, TU Braunschweig
  • Feldmann, F., 1987: Änderungen des Gehaltes an cyanogenem Glycosid und Scopoletin in Wurzeln von Hevea brasiliensis als Reaktion auf die Wechselwirkung mit bodenbürtigen Pilzen. Phytomedizin 17 (3), S. 27

Expertness

Agro-ecology - Agroforestry - Mixed Cropping Systems - Coordination - Fund raising