Watercress crop to salinity using a NFT hidroponic system / Resposta da Cultura do Agrião à Salinidade Utilizando um Sistema Hidropônico do Tipo NTF

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

After the Brazilian agriculture started to be outstanding in the scenery of the scientific researches, the great challenge started to be the productivity standardization in whole national territory. One of the main focus is being the semi-arid area for its water scarcity, so much quantitative as qualitative, for being an area with low annual precipitation and for their underground waters be usually salty waters. With this national challenge, it been spreading the soilless in some States, to improve the water use. With this increase soilless use it is appearing some difficulties due the lack of the information on this system. However, studies to be accomplished seeking to increase information on use of salty waters in soilless, and also looking for information on the answer salinity levels crop, are of fundamental importance to improve the investments in productions hydroponics, mainly in the Northeast of Brazil. Tends in view of the information lack for the hydroponic watercress crop, the objective of this work was: determine the threshold salinity of the crop watercress, in soilless and in soil; to propose a handling for the best system use, with saline waters. The experiment was developed in the Department of Rural Engineering of the Superior School Luiz of QueirozESALQ-USP, in a greenhouse of the type simple arch. A soilless system was used composed by 32 experimental units, that already installed previously. Each system hydroponics represented an independent portion. To discover the answer to the salts for the watercress in system hydroponics NFT and in the soil, they were evaluated eight salinity levels of the nutritious solution produced with NaCl, being the solution nutritious and more seven salinity levels of the water. It was observed, that in smaller levels of salts, the watercress grew better in relation to the larger levels. It was also observed that the answer crop to the salinity was better in the systems hydroponics. It was also noticed that the main symptoms of the salinity were the nanism, dark coloration leaves and their leaves were coriaceous. After the experiment, it is concluded that the saline treatments influenced significantly all income parameters crop, both in soilless and in soil; there was better development of the plants under salinity in the soilless, compared to the soil; the water consumption peaks plants in the soilless was influenced by the salinity.

ASSUNTO(S)

soilless agrião hidroponia salinidade da água water salinity watercress

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