Agronomic and ecotoxicological assessment of Alentejo soils in irrigated sunflower plots

Abstract

The development of irrigation in the south of Portugal has brought positive benefits, allowing crop diversification, agricultural expansion and intensification, and economic improvement in the region. However, this change in land use has been accompanied by an intensification of the use of production factors. Thus, the objective of this work was to evaluate the soil quality of two irrigated sunflower plots ((Girassol 1 (GR1) and Girassol 2 (GR2)), belonging to the area of the Alqueva Multipurpose Development (EFMA) through agronomic, ecotoxicological parameters and pesticide analysis. Soil samples were collected in two distinct phases of the plant's vegetative cycle, in the period of March/April (T1) and September/October (T2) of 2018. The analysis of the results allowed to conclude that the soils present slightly alkaline pH, with low content of organic matter and high concentrations of macronutrients. The amounts of pesticides were higher in the GR2 plot, samples that promoted greater toxicity to the test organisms used, namely at the end of the vegetative cycle. The results show the importance of integrative approaches in assessing the quality of agricultural soils, which allows for an increase in agro-environmental sustainability and an improvement in the analysis of soil health.