Evaluation of furrow irrigation and water availabity in fresh market tomatoes production at Rio das Pedras watershed.

Author(s)

Christiane Coletti

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Agrícola
• Defense date: 2005-02-23

Examining board members

Roberto Testezlaf; José Teixeira Filho; João Antonio Galbiatti; Rubens Duarte Coelho; Rinaldo de Oliveira Calheiros

• Advisor: Roberto Testezlaf

Abstract

Furrow irrigation is the mostly used system in the production of fresh market tomato in Brazil, although, its low application efficiency and the potential to contaminate water resources. The object of this study was to quantify the impacts of furrows irrigation management in the tomato crop, which can compromise the water availability (quantity and quality) at the Rio das Pedras Watershed, located in the cities of Mogi-Guaçu and Estiva Gerbi - SP. It were evaluated the irrigation performance parameters that could affect the readiness of watershed water resources. The following irrigation components were monitored: irrigation depth applied, furrow runoff and water percolation, soil water storage, reference evapotranspiration, and precipitation. Using the concentration levels of eight physical and chemical superficial water contaminants in six sample points during thirteen months, a water quality index was estimated to express the alterations of the watershed water quality. The water index was used to identify the nutrients and sediments transported inside the watershed. The results showed that the irrigation efficiency was around 26% in the farm; value considered low when compared to others irrigation system. The percolation loss was approximately 11%, and the runoff near to 1.5%. The water conduction loss (pipe and soil channels) was estimated in 61%, resulting in an overall irrigation loss of approximately 74% in the farm. However, the irrigation management applied in short length furrows generated acceptable water distribution uniformity. The water quality index showed agricultural chemical contaminations along the watershed, highly related to the fresh market tomato production, the major agricultural exploration in the watershed. It was observed the presences of NH3-N and NH3, mainly originated in the fertilization process used in the tomato crop production. The main research conclusion showed that the furrow irrigation is inefficiently operated in the fresh market tomato production, with excessive water loss affecting the watershed water quality with physical and chemical contaminants (AU)