Evaluation of the chemical composition and yield od crops as influenced by bacterial and mineral fertilization.

Abstract

The aim of this study was to evaluate the influence of an application of different rates of composite mineral fertilizers and their combination with bacterial inoculants (N-fixing Klebsiella planticola and Enterobacter spp.) on chemical composition and yield of the grain of maize and wheat cultivated in maize - winter wheat - maize rotation system on eutric cambisol type of soil during the three growing seasons: 2006, 2007 and 2008. Unfertilized soil was used as a control. The contents of nitrogen, phosphorus, potassium and crude proteins in grain samples were determined. Measuring of the yield of crops was carried out at the end of the vegetation. The results of the study showed that an application of high rates of composite mineral fertilizers and their combination with bacterial inoculants resulted in increased contents of nitrogen, phosphorus, potassium and proteins in the grains of both crops studied, which was noticeably observed in the milk-waxy maturity stage of maize in 2006 and 2008. The highest increase in the yield of the crops studied was obtained by the same mentioned treatments, although the combination of bacterial inoculants and lower rates of mineral fertilizers resulted in higher yields comparing to the application of lower rates of the pure mineral nutrients. The yield of maize was noticeably lower in the third year of the study than in the first.