ECO-SERVE : Sustainable provisioning of multiple ecosystem services in agricultural landscapes

Due to their involvement in many different soil processes, microbial communities play an important role in agricultural soils. Microbes are the engines driving nutrient transformation and release. Thinking of climate change a highly diverse and thus adaptive microbial community will be necessary to restore microbial mediated processes in the soil and hence soil functions to produce enough food and feed.

The overarching objective of the Swiss part of ECO-SERVE is to assess differences in soil nitrogen transformations and dynamics as well as the underlying microbial communities of farming systems - organic versus conventional - in the context of projected climate change induced rainfall variability.

A meta-analysis revealed that organically managed soils exerted a higher abundance and activity of microbial communities as compared to conventionally managed ones. This was in particular true for protease activity, an exo-enzyme hydrolysing organic nitrogen compounds. Organic fertilization and the share of ley in rotations seem to be the main drivers for these differences.

We showed, that organically managed soils harbour a higher capacity to release nitrogen from organic fertilizers and thus providing more nitrogen to crops under drought conditions. This translated in increased crop yields.
In addition, we observed organic systems to better maintain a diverse microbial community with functional genes encoding proteases under drought than conventional systems.

Implication for research

We delivered first insights into nitrogen provisioning potentials of soils and hereby involved microbial communities under various drought scenarios. Considering ecological intensification and the use of organic fertilizer, further knowledge about release of organically bound nitrogen and provisioning to plants at field scale is needed. This will help to develop plant nutritional strategies to efficiently supplying crops with nitrogen while simultaneously reducing losses.

Implication for practice

Our results suggest that organic management practices contribute to an increase in soil carbon and nitrogen stocks as well as microbial activity and abundance. In addition, we have shown that organic systems better maintain microbial diversity under drought which translated into an enhanced release of nitrogen from green manure and nitrogen provisioning for improved crop growth. Organic fertilization strategies are thus proposed as promising option to cope with drought stress, rendering agricultural systems more resilient.

Sustainable Provisioning of Multiple Ecosystem Services in Agricultural Landscapes (ECO-SERVE)