Growth, water consumption and mineral composition of watercress under hydroponic system with brackish water

Raquele M Lira,Ênio Ff Silva,Lilia G Willadino,Hammady R Soares,Gerônimo F Silva

doi:10.1590/s0102-053620180103

Raquele M Lira, Ênio Ff Silva + Show 3 more

Open Access

https://doi.org/10.1590/s0102-053620180103

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Abstract

ABSTRACT The underground water reserves in the semi-arid region present high salinity levels. However, the scarcity of the resource compels the use of this water for several human activities, including agriculture. The aim of this work was to evaluate the use of brackish water for watercress cultivation (Nasturtium officinale) in a hydroponic NFT system (laminar flow of nutrients) and effects on water consumption, growth, yield and nutrient extraction by the plant. We studied six levels of salinity (0.2; 1.2; 2.2; 3.2; 4.2 and 5.2 dS m-1), in a completely randomized experimental design, with four replicates. Salinity was obtained by the addition of NaCl into the local water supply, being these waters used to prepare the nutrient solution and to replace the evapotranspirated water volume. We noticed a reduction in leaf area, fresh and dry mass of shoot, K content in plant and water consumption of the crop and, increased contents of P, Na, Cl in the plants, with increasing salinity of the solution. The use of brackish water for watercress cultivation in hydroponics is possible as an alternative for producers who have availability of brackish water and restricted possibility of fresh water. A reduction in dry mass of plants was observed with increasing electrical conductivity.

Highlights

As reservas hídricas subterrâneas na Região Semiárida apresentam-se em grande parte com elevadas salinidades
The aim of this work was to evaluate the use of brackish water for watercress cultivation (Nasturtium officinale) in a hydroponic NFT system and effects on water consumption, growth, yield and nutrient extraction by the plant
Taking this hypothesis into account, in hydroponic cultivation, the crops, mainly the ones which show a short cycle, should promote the sustainable use of brackish water, due to the shorter period of exposure time to salt stress, resulting in the minimization of damage caused to plants by this stress

Summary

Introduction

As reservas hídricas subterrâneas na Região Semiárida apresentam-se em grande parte com elevadas salinidades. It is expected that the crops show more tolerance related to salinity than when growing under conventional system, due to constant availability of water in several kinds of hydroponic systems and insignificant matric potential contribution to total potential of water, representing a higher absorption of water and inputs by the plants for the same salt quantity (Soares et al, 2007) Taking this hypothesis into account, in hydroponic cultivation, the crops, mainly the ones which show a short cycle, should promote the sustainable use of brackish water, due to the shorter period of exposure time to salt stress, resulting in the minimization of damage caused to plants by this stress. Hortic. bras., Brasília, v.36, n.1, January - March 2018 water and input use efficiency, lower environmental risk and less depletion of commercial income (Maciel et al, 2012)

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