Impacto do hidrogel na redução da necessidade de irrigação no cultivo de alface (Lactuca sativa L.)

Abstract

Lettuce (Lactuca sativa L.) is a leafy vegetable of great importance in both nutrition and agriculture. It is a crop with high water demand, especially due to its shallow root system and the high-water content in its leaves, which constitute a large part of its biomass. Proper irrigation management is essential to ensure its growth, quality, and productivity, avoiding water stress that could compromise its development. However, it is crucial to balance the frequency and amount of water applied, preventing both deficits and excesses, which could harm the plant's health. This study aimed to evaluate the development of lettuce plants subjected to the use of agricultural hydrogel, with the purpose of measuring plant growth under different irrigation levels. Development variables were assessed, including total fresh weight of the plant, fresh weight of the aerial part, and stem diameter. The results showed that, in traditional cultivation without hydrogel, an irrigation level of 10.5 mm provided an average productivity of 85.1 g/plant and a total fresh weight of 89.1 g, while with hydrogel, an irrigation level of 7.5 mm achieved 77.9 g/plant and a total fresh weight of 81.5 g. For stem diameter, the best results were obtained with irrigation levels of 9 mm (1.4 cm) without hydrogel and 6 mm (1.2 cm) with hydrogel. These findings demonstrate significant savings in water and energy resources in lettuce cultivation under experimental conditions. It was concluded that the use of hydrogel in lettuce cultivation improves water management, especially under deficit conditions, due to its capacity to retain and gradually release water. Hydrogel reduces the impacts of water stress, increases water use efficiency, and contributes to more sustainable agricultural systems. However, its application requires adjustments to local conditions, as in saturated soils, it may cause root hypoxia and problems associated with excess moisture. The implementation of hydrogels can represent a significant advancement for agricultural sustainability in the country, offering a viable alternative for regions facing water scarcity and contributing to more efficient and sustainable food production.