02638naa a2200385 a 450000100080000000500110000800800410001910000210006024500850008126000090016630000210017549000090019652015810020565000110178665000180179765000130181565000190182865000090184765000210185665000120187765000230188965000160191265000090192865300330193765300080197065300060197865300300198465300080201465300400202265300060206265300090206870000170207770000220209477301360211616280662008-01-11       2004    bl ---       0--  u    #d1 aGUERRA, J. G. M.  aManaging carbon and nitrogen in tropical organic farming through green manuring.  c2004  ap. 125-140. v. 2  vv. 2  aOrganic farming is a growing trend in agricultural practice, philosophy and business in many parts of the world. The definition of organic farming is not always uniform. There are international initiatives to set definitions and common principles that would facilitate communication among farmers, scientists, extensionists, traders and consumers. Plant residue decomposition and photosynthesis are two major processes that control the carbon budget in nature. Sustainable agricultural systems depend on the understanding and management of these two processes. Nitrogen supply for crop production in organic farming may come from indigenous soil organic matter, plant residues, and animal manure as primary source. Animal manure is widely used as a source of nitrogen, but it may be scarce or expensive in some regions. An important source of nitrogen for crop production is biologically fixed atmospheric nitrogen. Green manuring is particularly important in organic production, giving to the farm the possibility of autonomy in carbon and nitrogen amendment production. It increases the functional biodiversity in the farm and keeps the soil covered for longer periods during the year. Farmers face a challenge to adjust the green manure in their production systems. A proper period and location of the legume to the crop system design is a strategic decision. It is important to synchronize the cycles of the legume and the main crop to maximize the benefit of this practice and to avoid and competition between the legume and the main crop for light, water, and nutrients.  acarbon  agreen manures  anitrogen  aorganic matter  asoil  aAdubação Verde  aCarbono  aMatéria Orgânica  aNitrogênio  aSolo  aBiological nitrogen fixation  aBNF  aC  aFazendinha agroecológica  aFBN  aFixação biológica de nitrogênio  aN  aSIPA1 aDE-POLLI, H.1 aALMEIDA, D. L. de  tIn: ADETOLA BADEJO, M.; TOGUN, A. O. Strategies and tactics of sustainable agriculture in the tropics. Ibadan: College Press, 2004.