[en] The aim of this thesis was to analyse the nutritional status of soybean culture in the main area of Argentina, mainly based on leaf analysis. In order to adequately perform this task, and for the sake of assessing several production areas, representative of the study region, samples were taken in the provinces of Santa Fe, Córdoba and Buenos Aires. Sampling was performed during the R1 stag i.e. flowering initiation; then samples were dried and the following nutrients were determined: nitrogen, phosphorus, potassium, calcium, sulphur, magnesium, zinc, manganese, cupper, iron and boron. The results obtained were evaluated by comparison with international tables of reference. Moreover, taken into account crop yield in each experimental plot, tables were adjusted based on the obtained data sets. The DRIS method was employed for assess the nutritional status of the crop. This methods is based on the study of the relationships between all the nutrients analyzed; also it was possible to generate norms for a subpopulation of high yield rates, higher than 3978 kg ha-1 after nutritional indices have been calculated for each study nutrient using the method proposed by Jones in 1981. Likewise, the rank of limitations by deficiency and the nutritional balance index were determined. The above results allowed evaluating the target nutritional status per province, to verify the most limiting nutrients and to predict the crop yield base on IBN assessment. Sulphur was the nutrient that most strongly limited crop yield in the main soybean area, and it was followed by nitrogen, potassium and magnesium. Within micronutrients, zinc and copper appeared as the most limiting elements. On the other hand, manganese and calcium were the elements showing the highest availability considering optimum of top high values. The obtained information should allow to the elaboration of nutrition plans that would be more tight-fitting to crops, using new nutrient recommendations that have not been used, until now. Moreover, such guidance can be considered as the start point for a better assessment of the capacity of a given soil to provide nutrients, also for decision making of professionals and producers and in addition as a method that could help to teaching at the university level.

[es] En esta tesis se analiza el estado nutricional del cultivo de soja en la zona núcleo argentina, a partir de análisis foliares. Para poder representar diferentes zonas productivas de esta región se realizaron muestreos en las provincias de Santa Fe, Córdoba y Buenos Aires, en el estadio de R1 (Inicio de floración); luego las muestras fueron secadas y analizados los nutrientes nitrógeno, fósforo, potasio, calcio, azufre, magnesio, zinc, manganeso, cobre, hierro y boro. A partir de los resultados obtenidos, se realizaron comparaciones con tablas internacionales de referencia y como se obtuvieron los rendimientos de cada lote, se ajustaron tablas a partir de esta base de datos. Para poder determinar el estatus nutricional del cultivo, se utilizó el método DRIS, que analiza las relaciones de todos los nutrientes, generando normas de una sub población de altos rendimientos mayor a 3978 kg ha-1, calculando los índices nutricionales para cada nutriente por el método propuesto por Jones 1981. Se determinó el orden de limitación por deficiencia y el índice de balance nutricional. Con estos resultados se pudo evaluar el estatus nutricional por provincia, verificar los nutrientes más limitantes y predecir a partir del IBN, el rendimiento del cultivo. El azufre fue el nutriente que limitó fuertemente la producción del cultivo en la zona núcleo, seguido por nitrógeno, potasio y magnesio. Entre los micronutrientes se encontraron a zinc y cobre como principales limitantes. Manganeso y calcio fueron los elementos que presentaron la mayor disponibilidad en valores óptimos o superiores. La información generada, permitirá elaborar planes de nutrición más ajustados a los cultivos, con recomendaciones de nutrientes que hasta hoy no se utilizan. Además son el punto de partida para una mejor interpretación de la capacidad de cada suelo de proveer nutrientes, para la toma de decisiones de profesionales, productores y como método de enseñanza en las universidades.