Authors: Honorato C. Pacco, Delvio Sandri, Sebastićn Avelino Neto, Marco Antonio Amaral Jr., Ananda Helena Nunes Cunha
The objective of this work was the modeling of the water retention curves in three different substrates used in production of tomato variety "Sweet grape". The experiments were carried out within the existing greenhouse on the campus of UEG- UnUCET. Is saturated with water three types of substrates (sand, 40% with a commercial substrate, natural coconut fiber and commercial substrate by 80% pine bark and 20% coconut fiber) for 48 hours contained in two plastic pots for each substrate, was instrumented with three pressure sensors in each plastic pots for 59 days, where pressure measurements was performed using a digital tensiometer. Was constructed wetlands curves and pressure for each substrate in our study, each reading pressure current humidity existing on the substrates. As a result it was observed that the substrate with coconut fibers has the best ability to retain water in the assay compared to sand substrates and commercial. The model allowed us to determine the choice of substrate with improved ability to retain water for tomato production and reduce leaching loss of macro and micro nutrients in a hydroponic culture, and also allows the automation system.