Nutrient demand of the carrot crop

摘要

The existing literature for the recommendation of fertilizers and diagnosis of the nutritional status of the carrot crop is outdated because it contemplates productivities lower than those currently obtained. The objective of this research was to characterize the nutritional demand of the carrot crop by estimating the dry matter content of the roots, the coefficient of biological utilization of the nutrients and the harvest index of dry matter and of the mineral nutrients, in? order to indicate fertilizers according to the desired productivity for winter and summer cultivations. We sampled 210 carrot plots located in the Alto Paranaíba region, Minas Gerais, Brazil, during 2012 and 2013. We determined the content of dry matter of the roots, the coefficient of biological utilization of the nutrients in the roots and leaves and the harvest index of dry matter and nutrients in the crop. Data were grouped in two groups of cultivations: Winter and summer. The harvest index of dry matter and of nutrients was bigger for the winter cultivars. Regardless of the growing season, the N, P, K, Mg and B were retained in greater amounts in the roots. Phosphorus had the highest harvest index, and the Cu, the lowest. The differences were insignificant in the nutritional demand of N, P, Ca, S, B, Cu and Zn between winter and summer cultivars for the average productivity obtained in each season. In the summer cultivars, the carrot accumulates greater amounts of Fe and lower of K, Mg and Mn when compared to winter. The modeling of the nutritional demand of the carrot crop can be carried out depending on the desired productivity and growing season.