Automatic controller to water plants

Leonardo Oliveira Medici,Ricardo Antunes Azevedo,Daniel Fonseca De Carvalho,Hermes Soares Da Rocha,Carlos Pimentel

doi:10.1590/s0103-90162010000600016

Leonardo Oliveira Medici, Ricardo Antunes Azevedo + Show 3 more

Open Access

https://doi.org/10.1590/s0103-90162010000600016

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Abstract

Despite the massive demand of water for plant irrigation, there are few devices being used in the automation of this process in agriculture. This work evaluates a simple controller to water plants automatically that can be set up with low cost commercial materials, which are large-scale produced. This controller is composed by a ceramic capsule used in common domestic water filters; a plastic tube around 1.5 m long, and a pressostate used in domestic washing machines. The capsule and the pressostate are connected through the tube so that all parts are filled with water. The ceramic capsule is the sensor of the controller and has to be placed into the plant substrate. The pressostate has to be placed below the sensor and the lower it is, the higher is the water tension to start the irrigation, since the lower is the pressostate the higher is the water column above it and, therefore, the higher is the tension inside the ceramic cup to pull up the water column. The controller was evaluated in the control of drip irrigation for small containers filled with commercial organic substrate or soil. Linear regressions explained the relationship between the position of pressostate and the maximum water tension in the commercial substrate (p < 0.0054) and soil (p < 0.0001). Among the positions of the pressostate from 0.30 to 0.90 m below the sensor, the water tension changed from 1 to 8 kPa for commercial substrate and 4 to 13 kPa for the soil. This simple controller can be useful to grow plants, applying water automatically in function of the water tension of the plant substrate.

Highlights

Water and nitrogen are two key resources considered main factors in limiting plant growth with approximately 70% of available water being used for irrigation (Medici et al, 2007; Lea and Parry, 2008, 2009; Saeed et al, 2008; Andrews et al, 2009; da Silva et al, 2009)
This simple device is adjustable and the present work is evaluating the relationship between its adjustment and the maximum water tension kept in two types of plant substrate
The evaluated watering controller was developed by Medici (2008) and is composed by a ceramic capsule used in common domestic water filters; a plastic tube around 1.5 m long and a pressostate used in domestic washing machines

Summary

Acionador automático para irrigar plantas

RESUMO: A despeito da enorme demanda por água na irrigação de plantas, existem poucos aparelhos para automação deste processo sendo usados na agricultura. Avaliou-se um acionador automático para irrigação, o qual pode ser confeccionado com materiais comerciais de baixo custo, pois são produzidos em larga escala. A cápsula é o sensor do acionador e deve ser posicionada dentro do substrato das plantas. O pressostato deve ser posicionado abaixo do sensor e quanto mais baixo ele estiver, maior é a tensão da água que aciona a irrigação, pois quanto mais baixo estiver o pressostato, maior é a coluna de água acima do mesmo e, portanto, maior é a tensão na cápsula cerâmica para puxar para cima a coluna de água. Entre as posições do pressostato de 0,30 a 0,90 m abaixo do sensor, a tensão da água variou de 1 a 8 kPa para o substrato comercial e de 4 a 13 kPa para o solo.

Introduction

Material and Methods

Results and Discussion