Serbian agricultural producers are currently facing a large number of challenges which have a significant influence on their business activities. Continuous monitoring and evaluation of existing family farms business activities is the only way to improve their profitability and enhance competitiveness in such conditions.

Mean positive correlation (r = 0,47**) between grain yield and number of plants per m² and strong correlation between grain yield and number of spikes per m² were established (r = 0,55**). Weak correlation was established between grain yield and productive tillering (r = 0,24**). Strong positive correlation (r = 0,51**) is between the number of spikes per m² and productive tillering, as well as between the number of plants per m² and number of spikes per m² (r = 0,68**).

At the experimental field "Radmilovac" of the Faculty of Agriculture of the University of Belgrade the study of the conservation of soil moisture in deep tillage Rigosol was carried out. The so called type of soil Rigosol was covered by wheat and maize. The Rigosol was formed by special treatment of the parent soil the Eutric Cambisol. The researches have been conducted during the most important phenophases of the crop growth, including formation of kernels, flowering, fertilization, grain filling and maturity.

In this experiment we used brown forest soil that has been used in long-term experiments, for 30 years, with increasing doses of introduced nitrogen fertilizer in variants. In order to determine the quantities of nitrogen fertilizer required for wheat, a calculation model has been applied.