Efeito de resíduos orgânicos e do fosfato monocálcico na volatilização de amônia em terra tratada com uréia
1995; Sociedade Brasileira de Ciência do Solo; Volume: 19; Issue: 2 Linguagem: Inglês
ISSN
1806-9657
Autores Tópico(s)Soil Management and Crop Yield
ResumoTo study the effect of adding monocalcium phosphate and organic materials to the soil, on the losses of ammonia by volatilization after surface application of urea, samples from the Ap horizon of Reddish Brown Podzolic (Rhodic Kanhapludalf), clay, located in the State of Sao Paulo, Brazil, were treated with vinasse, a liquid acid effluent from sugarcane alcohol distillery ; composted cattle manure ; composted city refuse ; or peat ; urea in solution, mixed or not with monocalcium phosphate in a 1 :1 ratio (w/w) was also added. Urea in solution and vinasse were uniformly distributed on the soil surface, while the solid organic materials were mixed with the top centimeter of soil. Volatilized ammonia was collected in a filter paper disc containing a known amount of H 2 O 4 , which was mantained at a distance of 5 cm above the soil placed, in a closed glass flask. The discs were removed dayly and the remaining acid was titrated with NaOH 0.02N Vinasse increased ammonia loss by 105%, cattle manure by 163%, city refuse by 187% and peat by 843%. Mixing monocalcium phosphate to urea reduced the loss by 21%. Periods of maximum volatilization were closely coincident to those of highest pH values.
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