RESUMO
Although the use of agrochemicals allowed increasing the crops productivity, in many cases led to soil deterioration. In this study, eight composite samples from different soils of two locations (San Martín and Anta) in Salta, Argentina, were collected and analyzed. All the samples were from loamy Entisols (0-20â¯cm depth) under reduced tillage without and with direct spray application of glyphosate. Twenty six variables were determined (physical, chemical, and biological soil quality indicators). From them, those of higher specificity and sensitivity to changes following glyphosate application were identified by a stepwise reduction of variables aided by statistical analysis. Samples were grouped regarding location and application of glyphosate, to identify differential effects upon variables, and glyphosate sensitive variables were selected by discarding those influenced by other factors. Thence, they were used to compose a first approximation to a combined soil quality indicator (CSQI) to assess the effect of glyphosate use in agriculture upon the soil. Overall, the set of physical variables showed the same discriminating structure as the biological set. Finally, two biological, two chemical, and two physical indicators resulted as the most specific to quality variations by the application of the herbicide, being the most sensitive the microbial biomass carbon and the (Aminomethyl)phosphonic acid concentration in soil. When these two were considered into a CSQI, it was possible to discriminate samples with the application of glyphosate (lower quality) from those without application (higher quality). To the best of our knowledge, this is the first attempt to propose a CSQI that could play an important role to prevent degradation in soils subjected to glyphosate application, as it could aid in the early detection of soil quality loss. This would provide to land managers a decision tool to let the land rest from glyphosate application, to ensure sustainable practices in agriculture.
Assuntos
Monitoramento Ambiental/métodos , Glicina/análogos & derivados , Herbicidas/análise , Poluentes do Solo/análise , Glicina/análise , Solo/química , GlifosatoRESUMO
BACKGROUND: The 2012 American College of Chest Physicians' Evidence-Based Clinical Practice (CHEST), the 2012 European Society of Cardiology, and the 2014 American Heart Association guidelines and published decision tools by LaHaye and Casciano offer oral anticoagulant (OAC) recommendations for patients with atrial fibrillation (AF). The aim of our study was to compare the net clinical benefit (NCB) of OAC prescribing that was concordant with these decision aids. METHODS: A cohort study of the 2001-2013 LifeLink claims data was used. NCB in concordance with each decision aid was defined as adverse events (thromboembolic and major bleed events) prevented per 10,000 person-years. Cox proportional hazard models were used to assess the relative risk of AF adverse events associated in concordance with each decision aid adjusted for potential confounders. FINDINGS: The study included 15,129 patients with AF, contributing 33,512 person-years. The NCB of the CHEST guidelines was the highest (NCB = 30.07; 95% confidence interval [CI] = 28.66, 31.49) and the European Society of Cardiology guidelines the lowest (NCB = 7.38; 95% CI = 5.97, 8.80). Significant unadjusted decreases in the risk of AF adverse events associated with concordant OAC use/nonuse were found for the CHEST guidelines (hazard ratio [HR] = .825; 95% CI = .695, .979), Casciano tool (HR = .838; 95% CI = .706, .995), and LaHaye tool (HR = .841; 95% CI = .709, .999); however, none were significant after multivariate adjustment. CONCLUSION: Concordant OAC use with any of the decision aids except for the aggressive LaHaye tool led to a positive NCB. The decision aids based on the CHA2DS2-VASc algorithm did not consistently improve the NCB compared to CHADS2-based aids. Recommending OAC use when CHA2DS2-VASc score = 1 resulted in a lower NCB when all other factors guiding recommendations were held constant.