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Nutrient input-output budget of shifting agriculture in eastern Amazonia


, : Nutrient input-output budget of shifting agriculture in eastern Amazonia. Nutrient Cycling in Agroecosystems 47(1): 49-57, 1996-

A case study on the nutrient input-output budget of slash and burn agriculture was carried out in Northeast-Para, Brazil, where such a land-use system has been practiced for about 100 years. A common cropping period lasts for two years and the fields lie fallow for 4 to 8 years. We quantified rates of deposition, fertilization, and losses due to the bum, harvest and leaching. Six fields of different phases in the rotational cycle were under study during a 19 month period. During the fallow period, the input of Na, K, Mg, N, P and S via deposition exceeded the estimated losses with the seepage water. The Ca budget was almost balanced. The balance of fields in the transition from the fallow to the cropping phase was negative for Na, K, Ca, Mg, N, and S. The P balance was positive when NPK fertilizer was applied, and negative without fertilizer application. The nutrient balance for K, Mg, Ca, N, and P was also negative on the field in transition from the cropping to the fallow period. The nutrient budget for an entire land-use cycle of 9 years was estimated by the "false time series approach". In the case of an NPK fertilization during the cropping period there were net losses of 75 kg K ha-1, 125 kg Ca ha-1, 16 kg Mg ha-1, 285 kg N ha-1 and 13 kg S ha-1. Na (86 kg ha-1) and P (11 kg ha-1) were accumulated. The harvest was the most important flux for the K (61%) and P (62%) output. The element transfer into the atmosphere during the bum caused the main losses of N (60%), S (65%), Ca (58%) and Mg (41%). The most important path of Na loss was leaching (92%). The net K losses were severe as they represented 45% of the K store found extractable in the soil down to 1 m depth and in the aboveground biomass. The presented results may be useful in planning a sustainable and environmentally protective method of land-use within a shifting cultivation system. It is strongly recommended that slash burning be abandoned in order to keep the nutrients in the ecosystem.

US$19.90

DOI: 10.1007/bf01985718


Other references

Horsey, P.J., 1971: Selective indications for ketamine anæsthesia. Proceedings of the Royal Society of Medicine 64(11): 1160-1160

Blijenberg B.G.; Leijnse B., 1981: The significance of surveys with respect to the determination of neo natal bilirubin. Journal of Clinical Chemistry & Clinical Biochemistry 19(4): 215

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Simmons, E.B., 1976: Economic research on women in rural development in Northern Nigeria. West African women play significant roles as farmers, traders, and entrepreneurs in their own right, and these roles are of central importance to the women, their families, and the economies of West African countries. Both national governments and...

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Cashner F.M.; Delatte S.W.; Von Almen T.K.; Olson G.A.; Olson R.D., 1982: Effects of melanotropin inhibiting factor i sex and weight on tonic immobility in lizards anolis carolinensis. Three experiments were done with the lizard, A. carolinensis, as a follow-up on the previous work which showed that MIF-I (melatropin inhibiting factor) reduced tonic immobility (TI) during the breeding season and that females and longer TI durati...

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