GENOTYPIC RESPONSE OF TWO SOYBEAN VARIETIES WITH REDUCED CONTENT OF KTI TO APPLICATION OF DIFFERENT NITROGEN LEVEL

The aim of this investigation was to estimate the effects of different amounts of nitrogen on the grain yield and nutritive value in two soybean genotypes (Laura and Lana). Studied varieties belong to different maturity groups (Laura is in the group I, while Lana is in the group II) and they both have reduced content of Kunitz trypsin inhibitor (KTI). Four treatments of fertilization were tested: 0 kg N ha-1, 30 kg N ha-1, 60 kg N ha-1 and 90 kg N ha-1. Field trials were carried out in dry land farming, at location Putinci, during the years 2008 and 2009. In both research years, variety Lana had higher grain yield and oil content then variety Laura. Method of nitrogen fertilization has been proved as an effective tool for increasing of grain yield and protein content in both varieties. The results of the study showed that application of 90 kg N ha-1 increased the grain yield and protein content of soybean more than application of other treatments (0, 30 and 60 kg N ha-All nitrogen fertilization levels decreased the oil content.