Modelagem da demanda nutricional e índices diagnósticos foliares para a cultura da cenoura

• Autor(a) principal: Dezordi, Luciel Rauni
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2037
• topic: Sistema Fertical; CUB; DRIS; CND; Fertical system; CUB; DRIS; CND; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO::FERTILIDADE DO SOLO E ADUBACAO

Literature for fertilizer recommendations and diagnosis of nutritional status of carrot cultivation is outdated because it includes productivity lower than the obtained ones in the country currently. This study aimed to estimate the necessary attributes for modeling nutritional demand of the main carrot cultivars; to propose fertilizer recommendation system for culture (FERTICALC Carrot); and to determine reference values for interpretation of carrot leaf analysis. Productivity of roots and leaves, root dry matter (DM) content, and nutrients levels in the root and shoot were quantified in 210 commercial stands of carrot located in Alto Paranaíba region, Minas Gerais State (MG), Brazil. To model the nutritional demand, the biological utilization coefficient (BUC) of nutrients and harvest index (HI) of DM and nutrients in the culture were estimated. The modeling was generated for both carrot cropping seasons (winter and summer). The proposed system for fertilizer recommendations took into consideration the crop nutritional demand and the nutrients supply by the soil. To model the nutrients supply, the literature was reviewed for finding related issue to the theme. Reference values (levels and optimum ranges of nutrients in the tissues) were generated for diagnosis of nutritional status by analyzing the sampled shoot at harvest time. The reference values were generated using the Critical Level (CL), Sufficiency Ranges (SR), Diagnosis and Recommendation Integrated System (DRIS) and Compositional Nutrient Diagnosis (CND) methods. The harvest index of DM and nutrients was higher for winter cultivars. Regardless of the growing season, the N, P, K, Mg, and B were mainly accumulated in roots. Differences in the nutritional demand of N, P, Ca, S, B, Cu, and Zn were insignificant among winter and summer crops for the average yields obtained in each season (80 and 60 Mg ha-1, respectively). The summer crop accumulated greater amounts of Fe and minor amounts of K, Mg, and Mn when compared to the winter crop. The developed FERTICALC proved to be efficient for fertilizer recommendation for the carrot crop. The reference values were in accordance with all evaluated diagnostic methods. However, they were different from those results found in the literature indicating that regionalized reference values allow better diagnosis of nutritional status. The Mn was the most limiting nutrient in carrot cultivation, followed by Mg, K, and Ca.