Risk assessment on zinc deficiency in maize crops in southeastern part of Romania

: Within the EU, according to Eurostat data, Romania ranks first in terms of agricultural area cultivated with maize, about 2.5 million ha. The study was conducted in southeastern part of Romania, an area with a share of approximately 19.2% of the total cultivated national area, in Ialomița, Călărași, Brăila, Tulcea and Constanța counties. The main purpose of the research was to evaluate the degree of zinc supply of the soils, and the nutritional status of maize plants with this microelement, for which, soil samples were taken from a depth of 0-20 cm and samples of plant in the phenophase of 4-7 leaves. The methodology for evaluating zinc regime consisted in determining the content of mobile Zn in soil, soluble in CH 3 COONH 4 -EDTA solution at pH 7; values calculation of the reaction-mobile phosphates index (RMPI) and the zinc deficiency index (ZnDI), in order to establish probability classes for zinc deficiency occurrence. Results shows that of total analyzed samples (92), depending the content of mobile Zn by probability classes, 43% samples belonged to high probability class, 33% to medium probability class and 24% to low probability class, until improbable. Regarding percentage values of reaction-mobile phosphates index (RMPI), showed a distribution of soil samples, according to the probability class by zinc deficiency occurrence, of 68% for samples with high and very high probability, 22% for low probability and 10% improbable. Finally, the probability of this phenomenon occurrence, assessed by the zinc deficiency index (ZnDI), led to a distribution of percentage values as follows: 54% high and very high probability class, 21% medium probability class, 12% low probability class and 13% improbable class. The results obtained regarding the soils classification in probability classes of Zn deficiency occurrence in maize crop, provides precise information to stakeholders for the implementation of technological solutions to prevent this phenomenon that can cause significant production losses.