Nitrate leaching through climatologic water balance in a fertigated coffee plantation


Autoria(s): Bortolotto,Rafael Pivotto; Bruno,Isabeli Pereira; Dourado-Neto,Durval; Timm,Luís Carlos; Silva,Adilson Nunes da; Reichardt,Klaus
Data(s)

01/12/2013

Resumo

Nitrate losses from soil profiles by leaching should preferentially be monitored during high rainfall events and during irrigation when fertilizer nitrogen applications are elevated. Using a climatologic water balance, based on the models of Thornthwaite and Penman Monteith for potential evapotranspiration, drainage soil water fluxes below the root zone were estimated in a fertigated coffee crop. Soil solution extraction at the depth of 1 m allowed the calculation of nitrate leaching. The average nitrate concentration in soil solution for plots that received nitrogen by fertigation at a rate of 400 kg ha-1, was 5.42 mg L-1, surpassing the limit of the Brazilian legislation of 10.0 mg L-1, only during one month. For plots receiving 800 kg ha-1 of nitrogen, the average was 25.01 mg L-1, 2.5 times higher than the above-mentioned limit. This information indicates that nitrogen rates higher than 400 kg ha-1 are potentially polluting the ground water. Yearly nitrate amounts of leaching were 24.2 and 153.0 kg ha-1 for the nitrogen rates of 400 and 800 kg ha-1, respectively. The six times higher loss indicates a cost/benefit problem for coffee fertigations above 400 kg ha-1.

Formato

text/html

Identificador

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-737X2013000600006

Idioma(s)

en

Publicador

Universidade Federal de Viçosa

Fonte

Revista Ceres v.60 n.6 2013

Palavras-Chave #Thornthwaite #Penman-Monteith #evapotranspiration #deep drainage #urea
Tipo

journal article