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Advisor(s)
Abstract(s)
A escassez de água, particularmente em regiões áridas e semiáridas, como a zona
Mediterrânea, representa um grande desafio para a agricultura, sobretudo num contexto
de alterações climáticas. É crucial desenvolver-se e adotar-se novas estratégias agrícolas
que promovam o uso eficiente da água e que permitam uma maximização das
produtividades. O presente estudo focou-se na avaliação dos efeitos da aplicação de um
polímero hidroretentor na redução da água de irrigação, na produtividade e qualidade em
tomate de indústria. O ensaio decorreu numa parcela de quatro hectares (Vale Queimado),
situada em Salvaterra de Magos, que foi dividida em dois grupos de dois hectares: um
grupo onde foi aplicado 22,5 kg/ha de polímero X no solo e um grupo de controlo
(testemunha). Verificou-se diferenças significativas no desenvolvimento das plantas,
especificamente largura e altura, entre ambos os tratamentos aos 40, 60, 80 e 100 dias
após plantação (p-value<0,05). Os resultados das amostras foliares, mostraram diferenças
significativas aos 40 e 60 DAP no azoto e no potássio, com o grupo do polímero X a
apresentar consistentemente concentrações superiores ao longo do ciclo cultural.
Relativamente ao cálcio, as diferenças foram significativas aos 100 DAP com a testemunha
a apresentar concentrações superiores. Ao nível da taxa de exsudação das raízes das
plantas, não foram observadas diferenças significativas entre os tratamentos (pvalue>0,05). Os resultados de produtividade não apresentaram diferenças
estatisticamente significativas, contudo o grupo do polímero X registou produtividades
superiores nas três metodologias avaliadas: +13,8 t/ha no shaking test, +2,3 t/ha na
colheita diferenciada de galerias e +14,4 t/ha no mapeamento da máquina colhedora.
Importa destacar que estes ganhos foram alcançados com uma redução expressiva no
volume de água aplicada (-1902,3 m³/ha, equivalente a 20,5%), monitorizada em tempo
real através de sondas de humidade do solo e caudalímetros. Esta redução, validada por
instrumentação precisa, assume uma importância crucial no contexto da agricultura
sustentável, traduzindo-se numa melhoria clara da eficiência hídrica, um avanço relevante
face à escassez de água e às alterações climáticas. Também, se observou uma menor
frequência de irrigação no grupo do polímero e uma maior eficácia de atuação ao nível da
humidade de solo nas camadas mais profundas do perfil do solo. Os resultados da
avaliação dos parâmetros de qualidade dos frutos apresentaram valores dentro do
expectável para a variedade UG16112 e foram semelhantes em ambos os grupos, pelo
que não se registaram diferenças significativas entre o ºBrix, cor (a/b), licopenos, pH e
firmeza. Este trabalho realça as vantagens da aplicação do polímero ao solo, que através
do seu mecanismo de intumescimento possibilita a retenção de água no solo e a sua libertação controlada para as plantas, mostrando-se uma ferramenta promissora e
sustentável para melhorar a gestão hídrica e o rendimento das culturas
Water scarcity, particularly in arid and semi-arid regions such as the Mediterranean zone, represents a major challenge for agriculture, especially in the context of climate changes. It is crucial to develop and adopt new agricultural strategies that promote efficient water use and allow for the maximization of crop yields. This study focused on evaluating the effects of the application of a hydro-retentive polymer on irrigation water reduction, productivity, and quality in processing tomato. The trial was conducted on a four-hectare field (Vale Queimado), located in Salvaterra de Magos, which was divided into two groups of two hectares each: one group where 22.5 kg/ha of polymer X was applied to the soil, and a control group (untreated). There were significant differences in plant development, specifically in width and height, between the two treatments at 40, 60, 80, and 100 days after planting (p-value < 0.05). Leaf sample results showed significant differences at 40 and 60 DAP for nitrogen and potassium, with the polymer X group consistently presenting higher concentrations throughout the crop cycle. Regarding calcium, significant differences were found at 100 DAP, with the control group showing higher concentrations. At the root exudation rate level, no significant differences were observed between treatments (p-value > 0.05). The productivity results did not show statistically significant differences; however, the polymer X group achieved higher yields in all three evaluated methodologies: +13.8 t/ha in the shaking test, +2.3 t/ha in the selective harvest of clusters, and +14.4 t/ha in the harvester's yield mapping. It is important to highlight that these gains were accomplished with a significant reduction in applied water volume (-1,902.3 m³/ha, equivalent to 20,5%), monitored in real time using soil moisture probes and flow meters. This reduction, validated by precise instrumentation, is of critical importance in the context of sustainable agriculture, representing a clear improvement in water-use efficiency, a significant advancement in the face of water scarcity and climate change. A lower irrigation frequency was also observed in the polymer group, along with greater effectiveness in maintaining soil moisture in deeper layers of the soil profile. Fruit quality parameters were within the expected range for the UG16112 variety and were similar in both groups, with no significant differences observed in ºBrix, color (a/b), lycopene content, pH, and firmness. This study highlights the advantages of applying the polymer to the soil, which, through its swelling mechanism, enables water retention in the soil and its controlled release to the plants, proving to be a promising and sustainable tool for improving water management and crop performance.
Water scarcity, particularly in arid and semi-arid regions such as the Mediterranean zone, represents a major challenge for agriculture, especially in the context of climate changes. It is crucial to develop and adopt new agricultural strategies that promote efficient water use and allow for the maximization of crop yields. This study focused on evaluating the effects of the application of a hydro-retentive polymer on irrigation water reduction, productivity, and quality in processing tomato. The trial was conducted on a four-hectare field (Vale Queimado), located in Salvaterra de Magos, which was divided into two groups of two hectares each: one group where 22.5 kg/ha of polymer X was applied to the soil, and a control group (untreated). There were significant differences in plant development, specifically in width and height, between the two treatments at 40, 60, 80, and 100 days after planting (p-value < 0.05). Leaf sample results showed significant differences at 40 and 60 DAP for nitrogen and potassium, with the polymer X group consistently presenting higher concentrations throughout the crop cycle. Regarding calcium, significant differences were found at 100 DAP, with the control group showing higher concentrations. At the root exudation rate level, no significant differences were observed between treatments (p-value > 0.05). The productivity results did not show statistically significant differences; however, the polymer X group achieved higher yields in all three evaluated methodologies: +13.8 t/ha in the shaking test, +2.3 t/ha in the selective harvest of clusters, and +14.4 t/ha in the harvester's yield mapping. It is important to highlight that these gains were accomplished with a significant reduction in applied water volume (-1,902.3 m³/ha, equivalent to 20,5%), monitored in real time using soil moisture probes and flow meters. This reduction, validated by precise instrumentation, is of critical importance in the context of sustainable agriculture, representing a clear improvement in water-use efficiency, a significant advancement in the face of water scarcity and climate change. A lower irrigation frequency was also observed in the polymer group, along with greater effectiveness in maintaining soil moisture in deeper layers of the soil profile. Fruit quality parameters were within the expected range for the UG16112 variety and were similar in both groups, with no significant differences observed in ºBrix, color (a/b), lycopene content, pH, and firmness. This study highlights the advantages of applying the polymer to the soil, which, through its swelling mechanism, enables water retention in the soil and its controlled release to the plants, proving to be a promising and sustainable tool for improving water management and crop performance.
Description
Dissertação, Mestrado, Engenharia Agronómica, Instituto Politécnico de Santarém, Escola Superior Agrária, 2025
Keywords
tomate de indústria uso eficiente de água qualidade produtividade polímero processing tomato efficient use of water quality productivity polymer
Citation
Carvalho, Vanessa Romão de (2025). Avaliação dos efeitos da aplicação de um polímero hidro retentor na redução de água de irrigação, na produtividade e qualidade em tomate de indústria. Dissertação de Mestrado na área da Engenharia Agronómica, apresentada na Escola Superior Agrária de Santarém. http://hdl.handle.net/10400.15/5824