Goenster et al. 2015. Gaseous emissions and soil fertility of homegardens in the Nuba Mountains, Sudan

Goenster, S., Wiehle, M., Predotova, M., Gebauer, J., Ali, A. M., and Buerkert, A.: Gaseous emissions and soil fertility of homegardens in the nuba mountains, sudan, J. Plant Nutr. Soil Sci., 178, 413-424, 10.1002/jpln.201400292, 2015.

 Abstract

Intensification of homegardens in the Nuba Mountains may lead to increases in C and nutrient losses from these small-scale land-use systems and potentially threaten their sustainability. This study, therefore, aimed at determining gaseous C and N fluxes from homegarden soils of different soil moisture, temperature, and C and N status. Emissions of CO₂, NH₃, and N₂O from soils of two traditional and two intensified homegardens and an uncultivated control were recorded bi-weekly during the rainy season in 2010. Flux rates were determined with a portable dynamic closed chamber system consisting of a photo-acoustic multi-gas field monitor connected to a PTFE coated chamber. Topsoil moisture and temperature were recorded simultaneously to the gas measurements. Across all homegardens emissions averaged 4,527 kg CO₂-C ha⁻¹, 22 kg NH₃-N ha⁻¹, and 11 kg N₂O-N ha⁻¹ for the observation period from June to December. Flux rates were largely positively correlated with soil moisture and predominantly negatively with soil temperature. Significant positive, but weak (r_s < 0.34) correlations between increasing management intensity and emissions were noted for CO₂-C. Similarly, morning emissions of NH₃ and increasing management intensity were weakly correlated (r_s  = 0.17). The relatively high gaseous C and N losses in the studied homegardens call for effective management practices to secure the soil organic C status of these traditional land-use systems.