Background Groundwater—especially for the use as drinking water—is a strictly protected resource in the existing guidelines for pesticide registration and drinking water protection in the EU. One aspect that has hardly played a role in this context so far is the attenuation of pesticide concentrations along the flow path from the regulatory leaching concentration at a depth of 1 m below the applied field to raw water abstraction systems. The soil metabolite N,N-dimethylsulfamide (DMS) is formed from two fungicidal substances: tolylfluanid and dichlofluanid. According to the EU guidance document on relevant metabolites in groundwater, DMS is a “non-relevant” metabolite. However, long-term application of the two active substances on permanent crops has resulted in elevated and quantifiable amounts of DMS in groundwater catchment areas of water supplying plants. Therefore, in the case of DMS, substantial monitoring data is available. This enables in combination with groundwater modeling, a quantitative analysis of the natural attenuation of DMS concentrations over time and distance. To this end, extensive real-world data from three case studies of drinking water catchment areas in Germany were analyzed. Results The environmental fate of DMS in soil and groundwater was evaluated according to the respective data determined at the study sites. Analyses using monitoring data and combined modeling approaches as well, were performed to obtain comparable results. These merged outcomes from monitoring and modeling show total attenuation factors of 12–93 from leachate at 1 m depth down to monitoring wells—close to raw water collection. If concentration attenuation further downwards to collected raw water is considered, the overall attenuation factor is even higher (40–246). Conclusions The conditions at the catchment areas of the three case studies are very diverse, thus providing a wide range of attenuating conditions. When following the path of DMS from its formation in soil below a treated field, to its leaching into the aquifer, and within the aquifer down to the raw water collection site, its concentration in water is continuously and consistently decreasing. The results from DMS represent conservative estimations due to non-sorptive, quick transport processes. Extended to other sorptive solutes, it represents the lower end of expected attenuation. Therefore, natural pesticide concentration attenuation processes are suggested for the consideration in regulatory pesticide risk assessments for a more realistic yet still protective evaluation of expected concentrations in raw water.

A growing and promising sector of precision agriculture is the site-specific application of pesticides, having a high potential for reductions in pesticide use. Within the research project ‘AssSys’, site-specific pesticide applications with a direct injection sprayer system and an automatic application assistant were evaluated economically with respect to herbicide and fungicide applications. The application assistant aims to support farmers in decision-making and implementation of site-specific pesticide applications either in the planning stage or as ex-post analysis. The economic assessment was based on field trials and scenario analysis referring to a model farm. The field trials were conducted in 2018 and 2019 in northern Germany. In the scenario analysis, two site-specific application scenarios were compared to conventional uniform treatment (100% of the field area). Weed monitoring was conducted as (1) standard procedure according to integrated pest management, (2) camera-based and (3) drone-based in the field trials. The pesticide application costs include pesticide costs, labour and machine costs of monitoring and pesticide applications. Investment costs of the necessary technical equipment for site-specific applications were included as annual labour and machine costs. As a major key performance indicator of partial budgeting at field level, extended gross margins were calculated. The economic scenario analysis showed pesticide application cost savings from 26 to 66% for site-specific applications compared to conventional applications. The average extended gross margin for site-specific applications of 787 € ha−1 compared to 631 € ha−1 for conventional application showed a clear economic advantage of the site-specific application scenarios. Site-specific pesticide applications can support farmers in implementing precise, sustainable and economically beneficial pesticide management. The technology presented may contribute to meet the goals of the European Green Deal to reduce use and risks of pesticides.

Essential to the quality of X‐ray analysis in crystallography, such as diffractometry and spectrometry, is a stable and reproducible X‐ray source. Commonly, different optical elements are utilized to provide a dedicated X‐ray beam. The stable alignment of all these components is a prerequisite in order to reduce aberrations and to achieve high signal‐to‐noise ratios. Besides such aberrations and electronically induced variations of the X‐ray primary beam intensity, the environmental conditions are of particular importance, most prominently the barometric pressure, humidity and temperature. In a qualitative as well as quantitative study, the influence of the environmental conditions on the primary beam intensity of a sealed tube with a Cu anode and their correlations are determined. For a common setup, utilizing a scintillation counter, laboratory as well as external conditions are monitored simultaneously for 28 d. Their individual influence on the X‐ray intensity and their correlations are evaluated by statistical analysis including time lag. By this comprehensive study, experimental intensity variations of up to ΔI/I = 1.153 ± 0.001% are determined during density of air changes of Δρ/ρ = 3.7 ± 0.6%. This is interpreted in terms of air transmission variations of up to TX‐ray = 1.137 ± 0.001% for a typical X‐ray analysis setup due to ambient barometric pressure, temperature and humidity changes for natural mid‐ and long‐term variations. Significant correlations with respect to daily and weekly cycles and in particular with ambient conditions are determined. These results are used for a time‐dependent absorption correction of the measured intensity, which reduces the standard error by about 25%.

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