Ahrens, W.A. 1994a. Glyphosate. In: Herbicide handbook, pp. 149-152. Seventh Edition. Weed Science Society of America.
Ahrens, W.A. 1994b. Paraquat. In: Herbicide handbook, pp. 226-228. Seventh Edition. Weed Science Society of America.
Amado, T.J.C., Bayer, C., Eltz, F.L.F. & De Brum, A.C.R. 2001. Potencial de culturas de cobertura em acumular carbono e nitrogênio no solo no sistema plantio direto e a conseqüente melhoria da qualidade ambiental. Rev. Bras. Ciên. Solo, 25:189-197.
Amado, T.J.C., Lovato, T., Conceição, P.C., Spagnollo, E., Campos, B. & Costa, C. 2005. O potencial de sequestro de carbono em sistemas de produção de grãos sob plantio direito na região sul do Brasil. In: Simpósio sobre Plantio direto e Meio ambiente; Seqüestro de carbono e qualidade da agua, pp. 63-71. Anais. Foz do Iguaçu, 18-20 Maio 2005.
Balota, E.L. 1996. Alterações microbiológicas em solo cultivado sob plantio direto. In R. Trippia dos Guimarães Peixoto, D.C. Ahrens & M.J. Samaha, eds. Plantio direto: o caminho para uma agricultura sustentável. Palestras do I Congresso Brasieleiro de Plantio Direto para uma Agricultura Sustentável. Ponta Grossa. 275 pp.
Bassi, L. 2000. Impactos sociais, econômicos e ambientais na microbacia hidrográfica do Lajeado São José, Chapecó, SC. Estudio de caso. Florianópolis, Brazil, EPAGRI. 50 pp.
Bauer, A. & Black, A.L. 1994. Quantification of the effect of soil organic matter content on soil productivity. Am. J. Soil Sci. Soc., 5: 185-193.
Bell, M.J., Moody, P.W., Connolly, R.D. & Bridge, B.J. 1998. The role of active fractions of soil organic matter in physical and chemical fertility of Ferrosols. Aust. J. Soil Res., 36: 809-819.
Bell, M.J., Moody, P.W., Yo, S.A. & Connolly, R.D. 1999. Using active fractions of soil organic matter as indicators of the sustainability of Ferrosol farming systems. Aust. J. Soil Res., 37: 279-287.
Bessam, F. & Mrabet, R. 2003. Long-term changes in particulate organic matter under no-tillage systems in a semiarid soil of Morocco. In: Proc. 16th ISTRO Conference, pp. 144-149. 13-18 July 2003, Brisbane, Australia.
Blair, N. & Crocker, G.J. 2000. Crop rotation effects on soil carbon and physical fertility of two Australian soils. Aust. J. Soil Res., 38: 71-84.
Blair, G.J., Lefroy, R.D. & Lisle, L. 1995. Soil carbon fractions based on their degree of oxidation, and the development of a carbon management index for agricultural systems. Aust. J. Soil Res., 46: 1459-1466.
Blair, N., Faulkner, R.D., Till, A.R. & Prince, K.E. 2003. The impact of plant residues with different breakdown rates on soil carbon and soil structure. In: Proc. 16th ISTRO Conference, pp. 175-181. 13-18 July 2003, Brisbane, Australia.
Brammer, H. 2000. Ploughpans and tillage problems. In: Agroecological aspects of agricultural research in Bangladesh, pp. 151-158. Dhaka, UPL.
Brito, L.F., La Scala Jr, N., Merques Jr, J. & Pereira, G.T. 2005. Variabilidade temporal da emissão de CO2 do solo e sua relação com a temperatura do solo em diferentes posições na paisgem em área cultivada com cana-de açúcar. In: Simpósio sobre Plantio direto e Meio ambiente; Seqüestro de carbono e qualidade da agua, pp. 210-212. Anais. Foz do Iguaçu, 18-20 de Maio 2005.
Brown, G.G., Oliveira, L.J., Norton, D., Alberton, O., Brandão Jr., O., Saridakis, G.P. & Torres, E. 2003. Quantifying scarab beetle-grub holes and their volume as affected by different tillage and crop management systems. In: Proc. 16th ISTRO Conference, pp. 213-218. 13-18 July 2003, Brisbane, Australia.
Brussaard, L. 1994. Interrelationships between biological activities, soil properties and soil management. In D.J. Greenland & I. Szabolcs, eds. Soil resilience and sustainable land use, pp. 309-329. Wallingford, UK, CAB International.
Brussaard, L. & Juma, N.G. 1995. Organisms and humus in soils. In A. Piccolo, ed. Humic substances in terrestrial ecosystems, pp. 329-359. Amsterdam, The Netherlands, Elsevier.
Calegari, A. 1998. The effects of winter green manure and no-tillage on soil chemical properties and maize yield.
Calegari, A., Darolt, M.R. & Ferro, M. 1998. Towards sustainable agriculture with a no-tillage system. Adv. Geo. Ecol., 31: 1205-1209.
Carbon Dioxide Information Analysis Center. 2003. National CO2 emissions from fossil-fuel burning, cement manufacture, and gas flaring: 1751-2000, by G. Marland, T.A. Boden & R.J. Andres, eds. (available at http://cdiac.esd.ornl.gov).
Castro Filho, C., Muzilli, O. & Podanoschi, A.L. 1998. Estabilidade dos agregados e sua relação com o teor de carbono orgânico num Latossolo roxo distrófico, em função de sistemas de plantio, rotações de culturas e métodos de preparo das amostras. Rev. Bras. Ciên. Solo, 22: 527-538.
CDR. 2000. Servicios financieros rurales y economía campesina sostenible. Un estudio de caso en el departamento de Lempira, Honduras. I. Informe principal. Centro de Estudios para el Desarrollo Rural, Universidad Libre de Amsterdam, The Netherlands. 80 pp.
Chan, K.Y., Heenan, D.P., Oates, A. & Munro, K. 2003. Hydraulic properties of an Alfisol with pre-existing pan under conservation tillage - effect of earthworms. In: Proc. 16th ISTRO Conference, pp. 300-304. 13-18 July 2003, Brisbane, Australia.
Choto, C. & Saín, G. 1993. Análisis del mercado de rastrojo y sus implicaciones para la adopción de la labranza de conservación en El Salvador. Síntesis de resultados experimentales del PRM 1992. Vol. 4. pp. 212-222.
Choto, C., Saín, G. & Montenegro, T. 1995. Productividad y rentabilidad del sistema de producción maíz-sorgo bajo labranza de conservación en El Salvador.
Coulombe, C.E., Dixon, J.B. & Wilding, L.P. 1996. Mineralogy and chemistry of Vertisols. In N. Ahmad & A. Mermut, eds. Vertisols and technologies for their management, pp. 115-200. Developments in Soil Science 24. Amsterdam, The Netherlands, Elsevier.
Crovetto, C. 1997. La cero labranza y la nutrición del suelo. In: Agricultura sustentable de alta producción, ya! pp. 73-78. 5o Congreso Nacional de AAPRESID, Mar del Plata, Argentina.
Curry, J.P. & Good, J.A. 1992. Soil faunal degradation and restoration. Adv. Soil Sci., 17: 171-215.
Dalal, R.C. & Mayer, R.J. 1986a. Long-term trends in fertility of soils under continuous cultivation and cereal cropping in Southern Queensland. I. Overall changes in soil properties and trends in winter cereal yields. Aust. J. Soil Res., 24, 265-279.
Dalal, R.C. & Mayer, R.J. 1986b. Long-term trends in fertility of soils under continuous cultivation and cereal cropping in Southern Queensland. II. Total organic carbon and its rate of loss from the soil profile. Aust. J. Soil Res., 24, 281-292.
Davidson, E.A. & Ackerman, I.L. 1993. Changes in soil carbon inventories following cultivation of previously untilled soil. Biogeochemistry, 20: 161-193.
Debarba, L. & Amado, T.J.C. 1997. Desenvolvimento de sistemas de produção de milho no sul do brasil com características de sustentabilidade. Rev. Bras. Ciên. Solo, 21: 473-480.
Derpsch, R. 1993. Sistema de Plantio Direto em Residuos de Adubos Verdes em Pequenas Propriedades no Paraguai - Desenvolvimento e Difusão. In: I Encontro Latino Americano sobre Plantio Direto na Pequena Propriedade, pp. 375-386. Ponta Grossa. Anais.
Derpsch, R. 1997. Importancia de la siembra directa para obtener la sustentabilidad de la producción agricola. In: Agricultura sustentable de alta producción, ya! pp. 153-176. 5o Congreso Nacional de AAPRESID, Mar del Plata, Argentina.
Douglas, M.G., Mughogho, S.K., Saka, A.R., Shaxson, T.F. & Evers, G. 1999. Report on an investigation into the presence of a cultivation hoe pan under smallholder farming conditions in Malawi. Investment Centre Division FAO/World Bank Cooperative Programme. Washington, DC, World Bank.
Duxbury, J.M., Smith, M.S. & Doran, J.W. 1989. Soil organic matter as a source and sink of plant nutrients. In D.C. Coleman, J.M. Oades & G. Uehara, eds. Dynamics of soil organic matter in tropical ecosystem, pp. 33-67. USA, University of Hawaii Press.
Elliot, L.F. & Lynch, J.M. 1984. The effect of available carbon and nitrogen in straw on soil and ash aggregation and acetic acid production. Plant Soil, 78: 335-343.
Elliot, L.F. & Lynch, J.M. 1994. Biodiversity and soil resilience. In J. Greenland & I. Szabolcs, eds. Soil resilience and sustainable land use, pp. 353-364. Wallingford, UK, CAB International.
FAO. 1974. Tree planting practices in African savannahs. FAO Forestry Development Paper No. 19. Rome.
FAO. 1979. Watershed development with special reference to soil and water conservation. FAO Soils Bulletin No. 44. Rome.
FAO. 1984. Tillage systems for soil and water conservation. FAO Soils Bulletin No. 54. Rome.
FAO. 1989. Soil conservation for small farmers in the humid tropics. FAO Soils Bulletin No. 60. Rome.
FAO. 1993. Soil tillage in Africa: needs and challenges. FAO Soils Bulletin No. 69. Rome.
FAO. 1994. Land husbandry. Components and strategy. FAO Soils Bulletin No. 70. Rome.
FAO. 1995. Tillage systems in the tropics. Management options and sustainability implications. FAO Soils Bulletin No. 71. Rome.
FAO. 2000. Fertilizers and their use. A pocket guide for extension officers. Fourth edition. FAO/IFA. 70 pp.
FAO. 2001. Conservation agriculture. Case studies in Latin America and Africa. FAO Soils Bulletin No. 78. Rome. 69 pp.
FAO. 2002. Farm management and economics. In: Training modules on Conservation Agriculture. FAO Land and Water Digital Media Series, Volume 22. Rome.
Fawcett, R.S. 1997. Influences of the no-till system on drinkability of water; consequences on water treatment and availability of water. In: II seminário internacional do sistema plantio direto, pp. 3-10. Passo Fundo. Anais.
Ferreira, M.C., Andrade, D.S., Chueire, L.M.O., Takemura, M. & Hungria, M. 2000. Tillage method and crop rotation effects on the population sizes and diversity of bradyrhizobia nodulating soybean. Soil Biol. Biochem., 32: 627-637.
Gassen, D.N. & Gassen, F.R. 1996. Plantio direto. O caminho do futuro. Aldeia Sul, Passo Fundo. 207 pp.
Glanz, J. 1995. Saving our soil: solutions for sustaining earth’s vital resource. Boulder, USA, Johnson Printing.
Greenland, D.J. 1958. Nitrate fluctuations in tropical soils. J. Agric. Sci., 50: 82-92.
Gregorich, E.G., Greer, K.J., Anderson, D.W. & Liang, D.C. 1998. Carbon distribution and losses: erosion and deposition effects. Soil Till. Res., 47: 291-302.
Guimarães, R.C., Buaski, E. & Masquieto, V.L.I. 2005. Bacia do Rio do Campo, Campo Mourão - PR. In: Simpósio sobre Plantio direto e Meio ambiente; Seqüestro de carbono e qualidade da agua, pp. 110-115. Anais. Foz do Iguaçu, 18-20 de Maio 2005.
Gupta, V.V.S.R. & Germida, J.J. 1988. Distribution of microbial biomass and its activity in different soil aggregate size classes as affected by cultivation. Soil Biol. Biochem., 20: 777-786.
Haney, R.L., Senseman, S.A. & Hons, F.M. 2002. Effect of roundup ultra on microbial activity and biomass from selected soils. J. Env. Qual. Madison.
Holland, E.A. & Coleman, D.C. 1987. Litter placement effects on microbial and organic matter dynamics in an agro-ecosystem. Ecology, 68: 425-433.
Hudson, B.D. 1994. Soil organic matter and available water capacity. J. Soil Wat. Con., 49(2): 189-194.
Hungria, M., Andrade, D.S., Balota E.L. & Collozzi-Filho, A. 1997. Importância do sistema de semeadura directa na populaçâo microbiana do solo. Comunicado Técnico 56. Londrina, Brazil, EMBRAPA-CNPSo. 9 pp.
Ingham, E.R. 2000. The soil food web. In: Soil biology primer. Rev. edition. Ankeny, USA, Soil and Water Conservation Society.
Izaurralde, R.C. & Cerri, C.C. 2002. Organic matter management. In: Encyclopedia of soil science, pp. 910-916. New York, USA, Marcel Dekker Inc.
Jenkinson, D.S. & Ayanaba, A. 1977. Decomposition of C-14 labelled plant material under tropical conditions. Soil Sci. Soc. Am. J., 41: 912-915.
Jones, M.J., & Wild, A. 1975. Soils of the West African savannah. Technical Communication No. 55. Commonwealth Bureau of Soils. Farnham, UK, Commonwealth Agricultural Bureaux.
Juma, N.G. 1998. The pedosphere and its dynamics: a systems approach to soil science. Volume 1. Edmonton, Canada, Quality Color Press Inc. 315 pp.
Juo, A.S.R. & Lal, R. 1977. The effect of fallow and continuous cultivation on physical and chemical properties of an Alfisol in western Nigeria. Plant & Soil, 47: 507-584.
Ladd, J.N. & Amato, M. 1985. Nitrogen cycling in legume cereal rotations. In B.T. Kang & J. Van der Heide, eds. Nitrogen management in farming systems in humid and sub-humid tropics, pp. 105-127. Haren, The Netherlands, Institute for Soil Fertility (IB), and Ibadan, Nigeria, International Institute for Tropical Agriculture.
Lal, R. 1991. Soil conservation and biodiversity. In D.L. Hawksworth, ed. The biodiversity of microorganisms and invertebrates: its role in sustainable agriculture, pp. 89-103. Wallingford, UK, CAB International.
Lal, R. 1994. Sustainable land use systems and soil resilience. In J. Greenland & I. Szabolcs, eds. Soil resilience and sustainable land use, pp. 41-67. Wallingford, UK, CAB International.
Lal, R. 2005. No-till farming and environment quality. In: Simpósio sobre Plantio direto e Meio ambiente; Seqüestro de carbono e qualidade da agua, pp. 29-37. Anais. Foz do Iguaçu, 18-20 de Maio 2005.
Lavelle, P. & Pashanasi, B. 1989. Soil macrofauna and land management in Peruvian Amazonia (Yurimaguas, Loreto). Pedobiologia, 33: 283-291.
Lavelle, P. & Spain, A. 2001. Soil ecology. Dordrecht, The Netherlands, Kluwer Academic Publishers.
Lefroy, R.D.B., Blair, G.J. & Strong, W.M. 1993. Changes in soil organic matter with cropping as measured by organic matter fractions and 13 C natural isotope abundance. Plant Soil, 155/156: 399-402.
Linn, D.M. & Doran, J.W. 1984. Effect of water-filled pore space carbon dioxide and nitrous oxide production in tilled and nontilled soils. Soil Sci. Soc. Am. J., 48: 1267-1272.
Lovato, T. 2001. Dinâmica do carbono e nitrogênio do solo afetada por preparos do solo, sistemas de culturas e adubo nitrogenado. Porto Alegre UFRGS. 133 pp. (PhD thesis)
Lovato, T., Mielnickzuk, J., Bayer, C. & Vezzani, F. 2004. Adição de C e N e sua relação com os estoques no solo e com o rendimento do milho em sistemas de manejo. Rev. Bras. Ci. Sol., 28: 175-187.
Machado, J.A. 1976. Efeito dos sistemas de cultivo reduzido e convencional na alteração de algumas propriedades fisicas e químicas do solo. Santa Maria. UFSM. (Tese de Doutorado)
Matson, P.A., Parton, W.J., Power, A.G. & Swift, M.J. 1997. Agricultural intensification and ecosystem properties. Science, 277: 504-509.
McGarry, D. 1996. The structure and grain size distribution of Vertisols. In N. Ahmad & A. Mermut, eds. Vertisols and technologies for their management, pp 231-259. Developments in Soil Science 24. Amsterdam, The Netherlands, Elsevier.
Mielniczuk, J. 1996. A sustentabilidade agrícola e o plantio direto. In R. Trippia dos Guimarães Peixoto. D.C. Ahrens and M.J. Samaha, eds. Plantio direto: o caminho para uma agricultura sustentável. Palestras do I Congresso Brasieleiro de Plantio Direto para uma Agricultura Sustentável. Ponta Grossa 1996. 275 pp.
Mollison, B. & Slay, R.M. 1991. Introduction of permaculture. Harare, The Tutorial Press. 198 pp.
Mrabet, R. 2000. Long-term no tillage influence on soil quality and wheat production in semiarid Morocco. Paper presented at the 15th ISTRO Conference, USA, 2-7 July 2000.
Mrabet, R., Ibno-Namr, K., Bessam, F. & Saber, N. 2001a. Soil chemical quality and implications for fertilizer management after 11 years of no-tillage wheat production systems in semiarid Morocco. Land Deg. Dev., 12: 505-517.
Mrabet, R., Saber, N., El Brahli, A., Lahlou, S., & Bessam, F. 2001b. Total, particulate organic matter and structural stability of a Calcixeroll soil under different wheat rotation and tillage systems in semiarid areas of Morocco. Soil Till. Res., 57: 225-235.
Mueller-Harvey, I., Juo, A.S.R. & Wild, A. 1989. Mineralization of nutrients after forest clearance and their uptake during cropping. In J. Proctor, ed. Mineral nutrients in tropical forest and savannah ecosystems, pp. 315-324. Spec. Publ. No. 9. The British Ecological Society. UK, Blackwell Scientific Publications.
Müller-Sämann, K. 1986. Bodenfruchtbarkeit und standortgerechte Landwirtschaft. Eine Studie über Massnahmen und Methoden im Tropischen Pflanzenbau. Schriftenreihe der GTZ No. 195. Eschborn, Germany.
Nicoloso, R.S., Lovato, T. & Lanzanova, M.E. 2005. Potencial de seqüestro ou emissão de carbono em áreas de integração lavoura-pecuária no sistema plantio direito. In: Simpósio sobre Plantio direto e Meio ambiente; Seqüestro de carbono e qualidade da agua, pp. 219-222. Anais. Foz do Iguaçu, 18-20 de Maio 2005.
Palm, C.A. & Sanchez, P.A. 1990. Decomposition and nutrient release patterns of the leaves of three tropical legumes. Biotropica, 22: 330-338.
Pangnakorn, U., George, D.L., Tullberg, J.N. & Gupta, M.L. 2003. Effect of tillage and traffic on earthworm populations in a Vertisol in South-East Queensland. In: Proc. 16th ISTRO Conference, pp. 881-885. 13-18 July 2003, Brisbane, Australia.
Paustian, K. 2002. Organic matter and global cycle. In: Encyclopedia of soil science, pp. 895-898. New York, USA, Marcel Dekker Inc.
Pieri, C., Evers, G., Landers, J., O’Connel, P. & Terry, E. 2002. No till farming for sustainable rural development. Agriculture and Rural Development Working Paper. Washington, DC, World Bank. 65 pp.
Pietola, L., Horn, R. & Yli-Halla, M. 2003. Effects of cattle trampling on soil hydraulic and mechanical properties. In: Proc. 16th ISTRO Conference, pp. 923-928. 13-18 July 2003, Brisbane, Australia.
Prasad, R. & Power, J.F. 1997. Soil fertility management for sustainable agriculture. New York, USA, Lewis Publishers. 356 pp.
Primavesi, A. 1984. Manejo ecológico del suelo. La agricultura en regiones tropicales. 5ta Edición. El Ateneo. Rio de Janeiro, Brazil. 499 pp.
Prior, S.A., Runion, G.B., Torbert, H.A., Rogers, H.H. &Reeves, D.W. 2003. Effects of elevated atmospheric CO2 on biomass production and carbon sequestration: conventional and conservation cropping systems. In: Proc. 16th ISTRO Conference, pp. 943-948. 13-18 July 2003, Brisbane, Australia.
Proffitt, A.P.B., Bendotti, S. & McGarry, D. 1995. A comparison between continuous and controlled grazing on a red duplex soil. I. Effects on soil physical characteristics. Soil Till. Res., 35:199-210.
Quideau, S.A. 2002. Organic matter accumulation. In: Encyclopedia of soil science, pp. 891-894. New York, USA, Marcel Dekker Inc.
Reicosky, D.C. 2005. Alternatives to mitigate the greenhouse effect: emission control by carbon sequestration. In: Simpósio sobre Plantio direto e Meio ambiente; Seqüestro de carbono e qualidade da agua, pp. 20-28. Anais. Foz do Iguaçu, 18-20 de Maio 2005.
Rice, C.W. 2002. Organic matter and nutrient dynamics. In: Encyclopedia of soil science, pp. 925-928. New York, USA, Marcel Dekker Inc.
Roth, C.H. 1985. Infiltrabilität von Latosolo-Roxo-Böden in Nordparaná, Brasilien, in Feldversuchen zur Erosionskontrolle mit verschiedenen Bodenbearbeitungs-systemen und Rotationen. Gött. Bod. Ber., 83: 1-104.
Ruedell, J. 1994. Pesquisa em plantio direto na palha e sua importância. In: IV Encontro nacional de plantio direto na palha, pp. 90-105. Cruz Alta.
Ruedell, J. 1995. Plantio direto na região de Cruz Alta. FUNDACEP. 134 pp.
Rummery, G. & Coleman, B. 1999. Does conservation farming pay? Cons. Farm. News., April 1999 (available at http://www.cfi.org.au).
Sampson, R.N. & Scholes, R.J. 2000. Additional human-induced activities. In R.T. Watson, I.R. Noble, B. Bolin, N.H. Ravindranath, D.J. Verardo & D.J. Dokken, eds. Land use, land use change and forestry. A special report of the IPCC, pp. 180-281. UK, Cambridge University Press.
Schnitzer, M. 1986. The synthesis, chemical structure, reactions and functions of humic substances. In R.G. Burns, G. dell’Agnola, S. Miele, S. Nardi, G. Savoini, M. Schnitzer, P. Sequi, D. Vaughan & S.A. Visser, eds. Humic substances: effect on soil and plants. Congress on Humic Substances. March 1986, Milan, Italy.
Schuette, J. 1998. Environmental fate of glyphosate. Environmental monitoring and pest management. Sacramento, USA, Department of Pesticide Regulation. (available at http://www.cdpr.ca.gov/docs/empm/pubs/fatememo/glyphos.pdf)
Siqueira, R., Yamaoka, R.S., Casão jr., R., Batista de Medeiros, G., Hamakawa, P.J. & De Souza Ladeira, A. 1993. Sistemas de preparo e coberturas vegetais em um solo de baixa aptidão agricola. In: I Encontro Latino Americano de Plantio Direto na Pequena Propriedade, pp. 221-237. Ponta Grossa, Anais.
Spagnollo, E. 2004. Dinâmica da matérica orgânica em agroecosistemas submetidos a queima e manejo dos resíduos culturais. UFSM, Santa Maria, RS, Brazil. 112 pp. (PhD thesis)
Stevenson, F.J. 1994. Humus chemistry. genesis, composition, reactions. 2nd edition. New York, USA, Wiley Interscience. 512 pp.
Swift, M.J., Heal, O.W. & Anderson, J.M. 1979. Decomposition in terrestrial ecosystems. Oxford, UK, Blackwell Scientific Publications.
Swift, M.J., Vandermeer, J., Ramakrishnan, P.S., Anderson, J.M., Ong, C.K. & Hawkins B.A. 1996. Biodiversity and agroecosystem function. In H.A. Mooney, J.H. Cushman, E. Medina, O.E. Sala & E.-D. Schulze, eds. Functional roles of biodiversity: a global perspective, pp. 261-298. New York, USA, John Wiley and Sons.
Tan, K.H. 1994. Environmental soil science. New York, USA, Marcel Dekker Inc. 304 pp.
Tan, K.H. & Binger, A. 1986. Effect of humic acid on aluminium toxicity in corn plants. Soil Sci., 14: 20-25.
Tate, R.L. 1987. Soil organic matter: biological and ecological effects. New York, USA, John Wiley & Sons. 291 pp.
Theng, B.K.G. 1987. Clay-humic interactions and soil aggregate stability. In P. Rengasamy, ed. Soil structure and aggregate stability, pp. 32-73. Proc. Institute of Irrigation and Salinity Research. Tatura, Australia.
Torstenson, L. 1985. Behaviour of glyphosate in soil and its degradation. In E. Grossboard & D. Atkinson, eds. The herbicide glyphosate, pp. 137-149. Butterworth & Co. Ltd.
Uehara, G. & Gilman, G. 1981. The mineralogy, chemistry and physics of tropical soils with variable charge clays. Boulder, USA, Westview Press. 170 pp.
Unger, P.W. 1978. Straw-mulch rate effect on soil water storage and sorghum yield. Soil Sci. Soc. Am. J., 42: 486-491.
Van der Werff, P.A. 1990. Soil and litter fauna. In B.H. Janssen & J.F. Wienk, eds. Mechanized annual cropping on low fertility acid soils in the humid tropics. A case study of the Zanderij soil in Suriname. Wageningen Agricultural University Papers 90-5.
Van Keer, K., Comtois, J.D., Ongprasert, S. & Turkelboom, F., eds. 1996. Options for soil- and farmer-friendly agriculture in the highlands of northern Thailand. Soil Fertility Conservation Project. Mae Jo University, Thailand, and Catholic University of Leuven, Belgium.
Vermeer, A.W.P. 1996. Interactions between humic acid and hematite and their effects on metal ion speciation. Wageningen University, The Netherlands. (PhD thesis)
Vieira, M. & Van Wambeke, J. 2002. Conservation agriculture and rural development. Experiences in El Salvador. LEISA Mag., 18 (3): 11-12.
Voss, M & Sidirias, N. 1985. Nodulaçâo da soja em plantio direto em comparaçâo com plantio convencional. Pesq. Agropec. Bras., 20: 775-782.
Whitbread, A.M., Lefroy, R.D.B. & Blair, G.J. 1998. A survey of the impact of cropping on soil physical and chemical properties in north-western New South Wales. Aust. J. Soil Res., 36: 669-681.
World Neighbors. 2000. Lessons from the field. Reasons for resiliency: toward a sustainable recovery after hurricane Mitch. Honduras. 32 pp.
