Soybean represents 9% of the whole agricultural area worldwide, being Brazil, United States of America and Argentina responsible for more than 65% of its production. Many technologies worked together to made its expansion possible to the tropics, highlighting breeding programs and nutritional developments. It is thanks to it that soybean area and yield increased intensively over the last 50 years in Brazil, being this culture, nowadays, responsible for more than 9% of the whole Brazilian exports market share. When the first genetically modified herbicide tolerant (GM HT) soybean was released, a remarkable step of the agricultural history was given. Almost 20 years later, in 2014, GM HT soybeans represents 95% of the whole planted area and is considered a great responsible to ensured glyphosate the tittle of the most successful pesticide in history. Because this technology provides an easier weed managing, it turns soybean into a more profitable culture and also provides higher yields. The nutritional management plays an important role on soybean production as well. A large parcel of the increased crop yield in Brazil in the last 20 years is due to the use of micronutrients. Manganese importance has increased among the micronutrients, due its usual deficiency which has been seen in soybean fields. This nutrient become unavailable for roots' uptake in high pH conditions in the soil, hence, foliar application is a more efficient alternative. The adoption of Mn foliar fertilizers reduces the use of Mn based resources in more than 422 thousand tons worldwide, which represents an economy of 91.25%. Manganese visual deficiencies has coincided with herbicide applications, mainly with the use of glyphosate, hence, it is very common to mix these products into the application tank before the pulverization. This practice is interesting because it reduces the mechanized operations in the field, and the emission of greenhouse gases into the environment. Studies have been shown antagonist interactions between Mn and glyphosate when they are mixed in the tank, however, the real chemical interactions between them, both in the application tank and in plant, still remain unclear. The goals of this study is to apply x-ray spectroscopy techniques to bring a better understanding about Mn and glyphosate interactions. X-ray fluorescence and absorption spectroscopy techniques will be applied to evaluate their interactions within the plant, by monitoring Mn absorption, kinetics, redistribution and chemical form with or without Glyphosate. Also we aim to characterize their chemical form when mixed in a solution.
News published in Agência FAPESP Newsletter about the scholarship: