Impact of soil management on the quantity and quality of soil organic matter (SOM) and its microbiome.

In the current context of global change and soil desertification, soil organic matter (SOM) plays an important role as carbon (C) sink, but also for maintaining soil fertility and soil functions. Quantity and quality of SOM depend largely upon soil management strategies that also affect microbial activity and diversity. In the present work we aim to obtain a better understanding of the interrelationship between SOM pools, microbial activity and diversity, and management of agricultural soils. To achieve this, we selected soils along a European gradient managed with and without catch crops, as well as soils with and without cover crops from an olive plantation close to Seville (Spain). The samples of the latter were taken from the top soil of the inter tree lanes managed with and without conventional tillage. For comparison, soils of the tree line treated with herbicides were also included in the study. The SOM composition of these soils will be characterized by solid-state NMR spectroscopy and related to its biochemical recalcitrance determined from the CO₂ production during a controlled microcosm experiment of at least 2 month (Respicond Apparatus IV). Soil microbial biomass C and N will be analysed by the chloroform fumigation-extraction method; whereas microbial composition and biomass and microbial activity will be performed using phospholipid fatty acids (PLFA) analysis and extracellular enzymatic essays, respectively. We hypothesisized that higher plant diversity increases SOM quantity and quality, which has a positive impact on soil microbial diversity and activity.

Acknowledgement: This work is financed by the project EJP Soil/Energylink, which received funding through the European Union’s Horizon 2020 research and innovation programme under grant agreement N° 862695 and Tudi, GA 101000224, also of the H2020 program.