Effect of different management on biochemical properties of organic matter in Fragi-Stagnic Albeluvisols

Abstract

This study was conducted to measure the concentrations of N_total, N-NH₄ ⁺, N-NO₃ ⁻, total organic carbon, dissolved organic carbon, and indole-3-acetic acid (IAA) and also activity of nitrate reductase as well as activity of urease from Fragi-Stagnic Albeluvisols' organic matter in a field experiment (crop rotation: potato – spring wheat – spring barley). Samples were obtained from long-term field studies at Eerika near Tartu, Estonia, and from the forest Tiksoja. The experimental plots were under different regimes of organic and mineral fertilizers. The concentrations of N_total, indole-3-acetic acid, activity of urease and C/N ratios were generally the highest in the forest soil Tiksoja. Application of organic and mineral fertilizers increased the activity of both enzymes as well as the concentrations of indole-3-acetic acid in soils. The various fertilizer regimes influenced biochemical factors in soils as well as crop yields. The increase of crop yields was associated with the activity of both enzymes and the content of indole-3-acetic acid in soils.

Keywords:

• Organic and mineral fertilization
• nitrogen
• carbon
• auxine
• enzymes
• crop yield

Acknowledgements

We wish to thank the Agricultural Research Centre (ARC) for chemical analysis, and Mrs Teresa Stachecka for technical support.