Managing Global Resources for a Secure Future

2017 Annual Meeting | Oct. 22-25 | Tampa, FL

406-6 Functional Diversity of Plants and Soil Fauna As an Important Control of N2o Emissions.

See more from this Division: SSSA Division: Soil Biology and Biochemistry
See more from this Session: Soil Biology and Biochemistry Session on Nitrogen Dynamics

Wednesday, October 25, 2017: 2:50 PM
Tampa Convention Center, Room 22

Jan Willem van Groenigen1, Diego Abalos2, Ingrid Lubbers3 and Gerlinde De Deyn2, (1)Dept of Soil Quality, Wageningen University & Research Centre, Wageningen, NETHERLANDS
(2)Dept. of Soil Quality, Wageningen University & Research centre (WUR), Wageningen, Netherlands
(3)Dept. of Soil Quality, Wageningen University, Wageningen, Netherlands
Abstract:
Agricultural soils are the dominant source of anthropogenic emissions of the greenhouse gas nitrous oxide (N2O). Emissions are related to soil parameters such as N and C availability, anaerobicity and pH. Soil biota can change N2O emissions indirectly by affecting these controlling soil parameters. Hitherto, most research on N2O emissions was aimed at the relation between the soil microbial community and N2O fluxes. Here we show that diversity of higher soil organisms such as plants and fauna can exert important controls over N2O emissions as well.
In a first study we used a plant functional trait approach to study the relation between plant species strategies and N2O emissions from fertilized soils. In a greenhouse experiment using monocultures of six grass species with different above- and below-ground traits, we found that acquisitive species reduced N2O emissions, produced higher total biomass and showed larger N uptake. Acquisitive species had 87% lower N2O emissions per unit of N uptake than conservative species. Structural equation modelling revealed that specific leaf area and root length density were key traits regulating the effects of plants on N2O emission and biomass productivity.

In a second study we linked functional diversity of soil fauna to N2O emissions in a 120-day incubation experiment with eight different species belonging to four different taxonomic groups (collembolans, earthworms, potworms and mites). Functional composition of the soil faunal community was key to explaining faunal-induced emissions: large ecosystem engineers such as earthworms were keystone species driving N2O emission. The co-presence of other saprotrophic soil biota led to diminished faunal-induced N2O emissions.
We conclude that biodiversity of higher soil organisms can control N2O emissions through a variety of trophic and non-trophic interactions. Our results underline the pivotal role that ecology plays in the soil biogeochemical cycle and may point the way towards novel mitigation strategies.

See more from this Division: SSSA Division: Soil Biology and Biochemistry
See more from this Session: Soil Biology and Biochemistry Session on Nitrogen Dynamics