N₂O emission from a loamy sand Spodosol as related to soil fertility and N-fertilizer application for barley and cabbage

Abstract

The aim of this field study was to compare N₂O emission from loamy sand Spodosol of North-Western Russia with two levels of soil fertility. Plots with soils of low fertility (LF) and high fertility (HF) were divided into two subplots receiving high and zero inputs of mineral N-fertilizer. Barley and cabbage were grown on the subplots. Direct N₂O fluxes were measured and cumulative N₂O fluxes calculated for each crop grown on different subplots during the growing season of 2006. The differences in cumulative N₂O fluxes from the LF and HF soils were significant for barley and insignificant for cabbage when no mineral N-fertilizer was added. The application of mineral N-fertilizer resulted in a significant increase in cumulative N₂O flux from both soils with barley but not with cabbage. The amount of N₂O emitted from the soil per crop yield unit was significantly higher for the LF soil than for the HF soil for both of the studied crops. The results showed that in relatively dry growing seasons it would be better to use the HF Spodosol rather than the LF one to grow crops as the HF soil, in spite of the higher cumulative N₂O flux, produced less N₂O per yield unit.

Keywords:

• nitrous oxide
• Spodosol
• soil fertility
• crop yields

Acknowledgements

The authors are very thankful to Dr. E.A. Olenchenko for providing the information on the crop yields. The authors also thank the unknown referee and Dr. B.D. Soane for very useful comments during the preparation of this paper.