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Zero hunger

Soil ecological engineering and management of soil biology. <BR>A contribution to achieving zero hunger? (Communication session)

EUROSOIL2020CONT-1729

ECOLOGICAL INTENSIVE MANAGEMENT PROMOTES BENEFICIAL PROTEOLYTIC SOIL MICROBIAL COMMUNITIES INVOLVED IN AGRO-ECOSYSTEM FUNCTIONING UNDER CLIMATE CHANGE-INDUCED RAIN REGIMES

Martina Lori^{* 1}, Gabin Piton², Sarah Symanzcik¹, Nicolas Legay³, Lijbert Brussaard⁴, Sebastian Jaenicke⁵, Eduardo Nascimento⁶, Filipa Reis⁶, Paul Mäder¹, Arnaud Foulquier⁷

¹Soil science, FiBL (Research institute of organic farming), Frick, Switzerland, ²Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, Grenoble, ³École de la Nature et du Paysage, INSA Centre Val de Loire, France, ⁴Soil Biology Group, Wageningen University & Research, Netherlands, ⁵Bioinformatics and Systems Biology, Justus-Liebig-University Giessen, Germany, ⁶Department of Life Sciences, Centre for Functional Ecology, Portugal, ⁷Univ. Savoie Mont Blanc, INRA, France

Content: Climate change induced rainfall variability will affect soil microbial communities and their biogeochemical cycling. Nitrogen (N) is one of the most limiting nutrients in agroecosystems and its cycling and availability is dependent on microbial driven processes. The hydrolysis of organic N is an important step in controlling soil N availability and plant nutrition. This study assessed the effect of management (ecological intensive vs. conventional intensive) on N-cycling processes (forage-N uptake and NO₃^- leaching) and related soil microbial communities (alkaline (apr) and neutral (npr) metallopeptidase gene abundance and apr diversity and composition as well as β-1,4-N-acetylglucosaminidase and leucine aminopeptidase activities) under simulated climate change-induced rain regimes. Terrestrial model ecosystems extracted from agroecosystems across Europe (Switzerland, Portugal, France) were jointly subjected to four different rain regimes (dry, wet, and intermittent compared to normal rain regimes) for 263 days. Structural equation modelling identified direct impacts of rain regimes on N-cycling processes, whereas N-related microbial communities were more resistant. The dry treatment reduced NO₃^- leaching and forage-N uptake whereas the wet treatment led to an increase. The intermittent rain regime increased NO₃^- leaching but not forage-N uptake. In addition to rain regime effects, management indirectly affected N-cycling processes by modifying N-related microbial community composition. In detail, ecological intensive management promoted a more beneficial N-related microbial community composition than conventional intensive management under climate change-induced rain regimes with positive effects on forage-N uptake, which in turn translated into decreased NO₃^- leaching. Additional exploratory analyses identified phosphorus-associated litter properties as possible drivers for the observed management effects on N-related microbial community composition.

Disclosure of Interest: None Declared

Keywords: agroecosystem, climate change adaptation, Ecosystem Functions, Nitrogen, soil microbial communities