Balanço de energia em cana-de-açúcar na região dos tabuleiros costeiros do Estado da Paraíba.

Abstract

The sugar cane is an important crop in the national scene, occupying large tracts of land, acting as agent both in relation to relevant social, and environmental. The micrometeorology allows studying the interactions of cultures with the environment, quantifying the energy flows and allows assessing the transformations of radiant energy into latent and sensible heat, and this information direct application in agriculture. The objective of this study was to characterize the components of energy balance in hourly and daily totals bases, as well as the partition of energy available for evapotranspiration, warming the environment and soil heating in sugarcane gropwn in the coastal plains of Paraiba state. For that, a micrometeorological station was settled in a commercial cultivation of ratoon cane variety RB 92.579 (third sheet) in the experimental field of the farm Capim II belonging to Distillery Miriri S/A, City of Capim-PB, from June to September 2011. Data were collected for net radiation, incident and reflected solar radiation, temperature of dry and wet bulb above the canopy and soil heat flux. Flows of silence latent and sensible were obtained by the method of energy balance based on the Bowen ratio. The variation of availability of solar radiation directly influences the energy balance. The highest hourly amplitudes were observed during the less rainy season (August - September) with values 347.54 W m"2. In terms of partition of energy, the energy available was, on average for the observation period (June to September). 78. 13% consumed as latent heat, 15,10% as sensible heat and 6. 91% as soil heat flux.