Sérgio Luiz Aguilar Levien

Wet bulb dimensions in surface drip irrigation

Information on the geometry of wetted soil volume under trickle irrigation is important for design and operation of this irrigation system, and also for the management of the irrigation. For this, six experiments were installed in different soils with the objective of evaluate the dimensions of the wetted bulb as function of emitter discharged and water application time, using the power model. It was concluded that the wetted bulb dimensions can be predicted satisfactorily using the power model for all the soils tested.

Causas da variação em produtividade e qualidade do melão em um Latossolo Vermelho-Amarelo fertirrigado

This work was carried out in Mossoro, RN, Brazil, with the objective of identifying soil and fertirrigation variables influencing melon yield and quality. Variables determinated were: yield (export and marketable type); quality (total soluble solids content and pulp firmness); fertirrigation (emitter discharge rate, elevation, distance to water inlet and fertilizer amount); soil chemical properties (pH, organic matter, Ca, Mg, K, Na, potential acidity, P, Cu, Zn, Fe and Mn) and physical properties (contents of clay, sand and silt, soil density and soil moisture). Descriptive statistics, Spearmans correlation and multiple regressions were used for data analysis. Fertirrigation and variables related to a higher water availability improved melon yield and decreased quality. A higher availability of P increased melon yield, while higher soil pH improved fruit quality. Levels of micronutrients Fe and Mn were harmful to the crop, however higher contents of Cu increased export type yield and total soluble solids content.

Estimativa de dimensões de bulbo molhado em irrigação por gotejamento superficial aplicando modelo de superfície de resposta

The information of depth and width in wetted zone soil under drip irrigation plays great significance in design and management in the irrigation system for the amount of water required to the plant. For that, six experiments were installed in different soils with the objective of evaluating the dimensions of the wet bulb in the drip irrigation depending on the emitter discharged and of the water application time, using the power model. The obtained results showed that the proposed model can be used to estimate the dimensions of the wetted bulb for the all soils.

KpClasseASIM: a tool to estimate the coefficient of the Class A pan.

A estimativa da evapotranspiracao de referencia (ETo) calculada pelo Tanque Classe A e um metodo indireto e de uso generalizado no Brasil devido a seu baixo custo e facilidade no manuseio. Objetivou-se com este trabalho apresentar uma ferramenta desenvolvida para auxiliar na determinacao do coeficiente do Tanque Classe A (Kp), utilizando diferentes metodologias propostas na literatura para a determinacao do mesmo. O software, apresentado neste trabalho, foi desenvolvido utilizando a linguagem de programacao C# no ambiente de desenvolvimento Microsoft® Visual C# 2005. O software, denominado KpClasseASIM (Simulador de Coeficiente do Tanque Classe A), possui uma unica tela a qual deve receber as informacoes de entrada, e apresenta as informacoes de saida, as quais serao de acordo com as metodologias utilizadas.