Sustainable Agricultural Practices for Managing Rice Crops to Minimize Environmental Contamination from the Pesticide Imazamox

Weed management is crucial for the sustainable production of rice (Oryza sativa L.), although herbicides such as Imazamox (IZX) can persist in soils, posing risks to soils and water resources. This two-year study evaluated the effects of soil physicochemical properties under different irrigation and tillage practices, with and without compost derived from olive mill waste, on IZX behavior. The treatments implemented were as follows: no-tillage and sprinkler (NT-S), conventional tillage and sprinkler (T-S), conventional tillage and flooding (T-F), and the corresponding regimes with compost amendment (NT-SC, T-SC, and T-FC). Sorption–desorption, dissipation, and leaching of the herbicide were assessed. The IZX adsorption was lower under soil collected from sprinkler irrigation, especially in NT-S, while compost reduced the adsorption under T-SC and T-FC. Dissipation was faster in NT-S and T-S soils, in which the half-life of IZX declined up to 30% relative to T-F. Furthermore, compost further accelerated herbicide dissipation, correlating with higher organic carbon content and microbial activity. The IZX losses via leaching were significantly reduced in soils irrigated by sprinkler in combination with compost, with values ≤ 48.5% of the IZX applied. These results indicate that the irrigation regime and organic amendment strongly influence soil physicochemical properties, then influencing the environmental fate of IZX. Integrated management using sprinkler irrigation and compost can mitigate IZX persistence and leaching, improve soil health, and reduce the risk of water contamination, representing a sustainable strategy for rice cultivation.