ESTUDO DE CASO EM ÁREA COM FERTIRRIGAÇÃO DE EFLUENTES DE INDÚSTRIA ALIMENTÍCIA EM BATAGUASSU - MS

Abstract

Fertigation with industrial effluents has been identified as a sustainable alternative for nutrient recycling and reducing dependence on mineral fertilizers, but its use requires rigorous monitoring to avoid environmental risks. The objective of this study was to evaluate the effects of effluent application on the chemical properties of soil cultivated with Tifton 85 grass, compared to a non-fertigated control area. Soil samples were collected at depths of 0–30, 30–60, and 60–90 cm in both areas, and analyses were performed for pH, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), organic matter (OM), cation exchange capacity (CEC), sum of bases (SB), base saturation (V%), and Percent Exchangeable Sodium (PST). The results showed that the fertigated area presented very high phosphorus levels in all layers, in disagreement with CONAMA Resolution No. 430/2011, in addition to potassium saturation in the CTC above the 5% limit established by CETESB. Sodium levels were higher than in the control area, reflected in higher PST values ​​(up to 3.9%), although still within the range considered safe (<5%). The soil in both areas was classified as sandy, a characteristic that increases susceptibility to nutrient leaching. It is concluded that fertigation promotes immediate fertility gains and can increase nutrient availability for Tifton 85, but presents medium- and long-term environmental risks, particularly due to excess phosphorus, high potassium saturation, and a tendency toward sodium accumulation. The sustainability of the practice depends on adjusting application rates in accordance with CONAMA Resolution No. 503/2021, on periodic monitoring of critical parameters, and on the adoption of corrective management practices.