Diagnose nutricional de lavouras de soja da região de Campo Novo dos Parecis, Mato Grosso

• Autor(a) principal: Locatelli, Marcus Vinicius
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5423
• topic: Soja, Diagnose nutricional; Lavouras comerciais; Soybean; Nutritional diagnosis; Commercial crops; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::CIENCIA DO SOLO

The nutritional diagnosis from samples of plant tissues of commercial crops, together with soil analysis, has provided more efficient fertilization schedules as well as higher yields. Crop advisers generally make their decisions as to crops fertilization based on critical levels and nutrient levels norms the database itself. The aim of this work was to obtain technical norms from the Kenworth Balanced Indexes (BK) as well as from its modification (KBIIV) which uses the index of variation (IV) instead of the coefficient of variation for each nutrient, and to the Diagnosis and Recommendation Integrated System (DRIS). BK and BK-IV focus on the nutritional balance aspect, which is the analysis of each isolated nutrient, while DRIS focuses on nutrient balance in relation to the whole nutrient status. The study also had the objective of diagnosing the nutritional status of some soybean crops and identifying which were the more problematic nutrients either by deficiency or excess, as well as those which were more balanced and evaluate the variability over time of the BK, BK-IV and DRIS norms and its implication on the diagnoses. Based on the leaf samples levels of N, P, K, Ca, Mg, S, Fe, Zn, Cu, Mn and B from 790 soybean crops from Campo Novo dos Parecis, state of Mato Grosso, from five years, and on the crops yields the norms of the diagnosis methods KBI, KBI-IV and DRIS were obtained. The crops which composed the high yielding subpopulations for each year, and from which the norms were generated, were those which produced yields equal or superior to the average plus 1/3 the standard deviation, encompassing 33.5 % of the crops in the first year, 41.4 % in the second year, 37.2 % in the third year, 38.9 % in the fourth year and 42.8 % in the fifth year. Nitrogen was the most frequently balanced nutrient throughout the five years evaluated for soybean crops, and the most limiting nutrients were Mg, S, K, Mn, Cu and Zn. The Frequency of Agreeing Diagnoses of around 80.0 % between BK and BK-IV showed high redundancy between them, what did not happen when their diagnoses were compared to the DRIS diagnoses, with average agreements lower than 50.0 %. The diagnoses obtained from the norms originated from databases of previous years agreed little with diagnoses obtained from the norms of the year considered.