Pesticides are needed to maintain high production in the vineyard area of La Rioja (Spain), and monitoring their spatial distribution is a priority for preserving the quality of natural resources. Accordingly, the purpose of this work was to conduct a study to evaluate the presence and seasonal distribution of herbicide and insecticide residues in ground and surface waters in this region. The monitoring network comprised 12 surface waters and 78 groundwaters, covering the three subareas (63,593ha) into which the vineyard region is divided. The quality of natural waters was examined through the analysis of twenty-two herbicides, eight of their main degradation products, and eight insecticides. Pesticides were extracted by solid-phase extraction, and analysed by gas chromatography-mass spectrometry or by liquid-chromatography-mass spectrometry. The results reveal the presence of most of the herbicides and insecticides included in the study in one or more of the samples collected during the four campaigns. The herbicide terbuthylazine and its metabolite desethylterbuthylazine were the compounds more frequently detected (present in >65% of the samples across all the campaigns). Other compounds detected in >50% of the samples in one sampling campaign were the herbicides fluometuron, metolachlor, alachlor and ethofumesate. Insecticides were present in a small number of samples, with only pirimicarb being detected in >25% of the samples in March and June campaigns. The results reveal that the sum of compounds detected (mainly herbicides) was higher than 0.5μgL-1 in >50% of the samples, especially in the campaigns with the highest application of these compounds. A possible recovery of the quality of the waters was detected outside the periods of crop cultivation, although more monitoring programmes are needed to confirm this trend with a view to preventing and/or maintaining the sustainability of natural resources.

Sustainable agriculture practices and integrated pest management for avoiding environmental pollution are necessary to maintain a high yield in vineyard areas. Pesticide residues in groundwater in a vineyard area of La Rioja (Spain) have been evaluated in previous years, and they could now have varied after farmers have adopted the different measures recommended. Accordingly, this research's objectives were (i) to evaluate the occurrence and seasonal distribution (spring, summer, and autumn samplings) of pesticides (36) plus their degradation products (DP) (11) in water and soil samples (23 + 15) in La Rioja (Northern Spain), and (ii) to compare the current water quality (2019) with that determined previously (2011). A multi-residue method based on solid phase extraction (for water samples) or solid liquid extraction (for soil samples) and high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS) was used to determine and quantify pesticides. The results reveal the presence in waters of 30 compounds from those selected (15 fungicides + 2 DP, 7 insecticides + 1 DP, and 3 herbicides +2 DP), with 14 of them at concentrations > 0.1 μg L^-1 (water quality threshold for human consumption). The highest number of compounds was detected in summer (waters) and spring (soils). The pesticides most frequently detected in water samples were the fungicides metalaxyl, tebuconazole, and boscalid, with the last one being the compound found in the highest number of soil samples. The comparison of water pollution in 2011 and 2019 indicates a significant decrease in the total concentration of herbicides, fungicides and insecticides in 95-100%, 76-90%, and 42-85% of samples in the three campaigns, respectively. The results indicate that an optimized and sustainable use of pesticides in intensive and high-yield agricultural areas could reduce environmental pollution.