Plant-soil synchrony in nutrient cycles : learning from ecosystems to design sustainable agrosystems

2024

Article référencé dans le Web of Science WOS:001130359600001

Fontaine S., Abbadie L., Aubert M., Barot Sébastien, Bloor J. M. G., Derrien D., Duchene O., Gross N., Henneron L., Le Roux X., Loeuille N., Michel J., Recous S., Wipf D., Alvarez G.

Global Change Biology, 2024, 30 (1), e17034 [24 p.] ISSN 1354-1013

Redesigning agrosystems to include more ecological regulations can help feed a growing human population, preserve soils for future productivity, limit dependency on synthetic fertilizers, and reduce agriculture contribution to global changes such as eutrophication and warming. However, guidelines for redesigning cropping systems from natural systems to make them more sustainable remain limited. Synthetizing the knowledge on biogeochemical cycles in natural ecosystems, we outline four ecological systems that synchronize the supply of soluble nutrients by soil biota with the fluctuating nutrient demand of plants. This synchrony limits deficiencies and excesses of soluble nutrients, which usually penalize both production and regulating services of agrosystems such as nutrient retention and soil carbon storage. In the ecological systems outlined, synchrony emerges from plant-soil and plant-plant interactions, eco-physiological processes, soil physicochemical processes, and the dynamics of various nutrient reservoirs, including soil organic matter, soil minerals, atmosphere, and a common market. We discuss the relative importance of these ecological systems in regulating nutrient cycles depending on the pedoclimatic context and on the functional diversity of plants and microbes. We offer ideas about how these systems could be stimulated within agrosystems to improve their sustainability. A review of the latest advances in agronomy shows that some of the practices suggested to promote synchrony (e.g., reduced tillage, rotation with perennial plant cover, crop diversification) have already been tested and shown to be effective in reducing nutrient losses, fertilizer use, and N2O emissions and/or improving biomass production and soil carbon storage. Our framework also highlights new management strategies and defines the conditions for the success of these nature-based practices allowing for site-specific modifications. This new synthetized knowledge should help practitioners to improve the long-term productivity of agrosystems while reducing the negative impact of agriculture on the environment and the climate. Reviewing the latest advances in ecology, biogeochemistry, and agronomy, we explain how the capacity of natural ecosystems to be sustainably productive largely results from a coordination between plant- and soil-related processes, synchronizing the supply of soluble nutrients by soil biota with fluctuating plant nutrient demand. Supported by four ecological systems, this synchrony limits deficiencies and excesses of soluble nutrient, which usually penalize both production and regulating services of agrosystems. We explain why plant-soil synchrony challenges the concept of soil fertility and how greater synchrony can be achieved in various pedoclimatic contexts to promote agroecosystem production, nutrient retention, and carbon storage.

Sciences du milieu [021] ; Pédologie [068] ; Sciences du monde végétal [076] ; Etudes, transformation, conservation du milieu naturel [082]

Fonds IRD [F B010088870]

fdi:010088870