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Zero hunger

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

EUROSOIL2020CONT-1736

SOIL BIODIVERSITY FOR AGRICULTURAL PRODUCTION AND ENVIRONMENTAL INTEGRITY

Franz Bender^{* 1}, Timothy M. Bowles², Kate Scow³, Marcel van der Heijden¹

¹Dept. of Agroecology and Environment, Plant-Soil Interactions, Agroscope, Zürich, Switzerland, ²Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, ³Dept. of Land, Air and Water Resources, University of California, Davis, United States

Content: Soil biodiversity is a regulator of ecosystem functioning. However, the extent to which soil biota directly contribute to agricultural production and how soil management affects this is not well understood. Here, we provide evidence that soil organisms can substantially contribute to agricultural production while reducing environmental impacts.

In a model study conducted in outdoor lysimeters, we investigated how changes in the diversity and community composition of soil organisms affect crop yield and N losses through leaching, as well as through emissions of N-gases. The study provides evidence that a reduction in soil biological complexity can impair N cycling and lead to reduced crop yields and strongly increased nutrient losses to water bodies and atmosphere, including increased losses of the greenhouse gas N₂O.

A field survey across a range of sites differing in management intensity in the California central valley addressed the question whether increasing management intensity leads to reduced abundance and/or diversity of soil organisms and whether these changes result in negative effects on ecosystem functions. The study showed that the abundances of different soil organisms groups relate to nutrient losses and crop yields.

In an applied field experiment, the in-situ effects of long-term agricultural management on the community composition of plant symbiotic arbuscular mycorrhizal fungi (AMF) was studied. Moreover, it was tested to what extend these AMF communities contribute to crop yields. This was done by planting a non-mycorrhizal tomato mutant and its mycorrhizal progenitor into four differently managed corn-tomato rotations at a replicated long-term field trial. This study showed that the management of crop rotations can shape AMF community composition. Moreover, it provided in-situ evidence that, depending on management, native AMF communities can contribute to up to 33% of tomato yields.

Finally, we present resuIts of greenhouse and field studies testing, whether inoculations with AMF can promote crop growth. Effects differed depending on crop type. Moreover, we found that the presence of further soil microorganisms seems to affect AMF effects on crop yield.  

Cumulatively, our results highlight the fundamental value of soil biological communities for sustainable agricultural production and environmental integrity. Long-term adjustments of crop rotations and field inoculations with AMF could provide viable strategies for soil-ecological engineering, the integration of soil biological benefits into agricultural production schemes. Moreover, effective communication strategies for scientific results need to be implemented to increase the adoption of soil life promoting practices and to preserve the valuable resource of soil biodiversity

Disclosure of Interest: None Declared

Keywords: Arbuscular mycorrhizal fungi, corn, N cycling, Nitrous Oxide Emissions, tomato