The 4 per 1000 initiative aims to restore carbon storage in soils to both mitigate climate change and contribute to food security. The French National Institute for Agricultural Research conducted a study to determine the carbon storage potential in French soils and associated costs. This paper is a part of that study. It reviews recent advances concerning the mechanisms that controls C stabilization in soils. Synthetic figures integrating new concepts should be of pedagogical interest.

The intensive management of large-scale oil palm plantations may result in high nutrient leaching losses which reduce soil fertility and potentially pollute water bodies. The reduction in management intensity with lower fertilization rates and with mechanical weeding instead of the use of herbicide results in lower nutrient leaching losses while maintaining high yield. Lower leaching results from lower nutrient inputs from fertilizer and from higher retention by enhanced cover vegetation.

We generate 30-year mean water erosion estimates in global maize and wheat fields based on daily simulation outputs from an EPIC-based global gridded crop model. Evaluation against field data confirmed the robustness of the outputs for the majority of global cropland and overestimations at locations with steep slopes and strong rainfall. Additionally, we address sensitivities and uncertainties of model inputs to improve water erosion estimates in global agricultural impact studies.

We present an in-depth model analysis of transient peatland area and carbon dynamics over the last 22 000 years. Our novel results show that the consideration of both gross positive and negative area changes are necessary to understand the transient evolution of peatlands and their net effect on atmospheric carbon. The study includes the attributions to drivers through factorial simulations, assessments of uncertainty from climate forcing, and determination of the global net carbon balance.

Soil phosphorus (P) management is a critical challenge for agriculture worldwide; yet, simulation models of soil P processes lag those of other essential nutrients. In this review, we identify hindrances to measuring and modeling soil P pools and fluxes. We highlight the need to clarify biological and mineral interactions by defining P pools explicitly and using evolving techniques, such as tracing P in phosphates using oxygen isotopes.

Dimethyl sulfide, a volatile compound produced as a byproduct of marine phytoplankton activity, can be emitted to the atmosphere via gas exchange. In the atmosphere, DMS is oxidized to cloud condensation nuclei, thus contributing to cloud formation. Therefore, oceanic DMS plays an important role in regulating the planet's climate by influencing the radiation budget. In this study, we use an artificial neural network model to update the global DMS climatology and estimate the sea-to-air flux.

In this study, we analyze the seasonal changes in the dissolved organic matter (DOM) quality (based on its optical properties) in four Amazon floodplain lakes. DOM plays a fundamental role in surface water chemistry, controlling metal bioavailability and mobility, and nutrient cycling. The model proposed in our paper highlights the potential to study DOM quality at a wider spatial scale, which may help to better understand the persistence and fate of DOM in the ecosystem.

The isotopic composition of boron in carbonate shells of marine unicellular organisms is a popular tool to estimate seawater pH. Usually, many shells need to be dissolved and measured for boron isotopes, but the information on their spatial distribution is lost. Here, we investigate two techniques that allow for measuring boron isotopes within single shells and show that they yield robust mean values but provide additional information on the heterogeneity within and between single shells.

We quantified the changes in stem and soil nitrous oxide (N₂O) fluxes with forest conversion to cacao agroforestry in the Congo Basin, Cameroon. All forest and cacao trees consistently emitted N₂O, contributing 8–38 % of the total (soil and stem) emissions. Forest conversion to extensively managed (>–20 years old) cacao agroforestry had no effect on stem and soil N₂O fluxes. Our results highlight the importance of including tree-mediated fluxes in the ecosystem-level N₂O budget.

Cryptogamic organisms, such as bryophytes, lichens, and algae, cover major parts of vegetation in the Amazonian rain forest, but their relevance in biosphere–atmosphere exchange, climate processes, and nutrient cycling is largely unknown. Over the duration of 2 years we measured their water content, temperature, and light conditions to get better insights into their physiological activity patterns and thus their potential impact on local, regional, and even global biogeochemical processes.

The impact of Saharan dust deposition events on the Mediterranean Sea ecosystem was studied during a basin-scale survey (PEACETIME cruise, May–June 2017). Short-term responses of the zooplankton community were observed after episodic dust deposition events, highlighting the impact of these events on productivity up to the zooplankton level in the poorly fertilized pelagic ecosystems of the southern Mediterranean Sea.

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are used as a paleothermometer based on their temperature dependence in global soils, but aquatic production complicates their use in lakes. BrGDGTs in the water column of Lake Chala, East Africa, respond to oxygen conditions and mixing. Changes in their signal can be linked to bacterial community composition rather than membrane adaptation to changing conditions. Their integrated signal in the sediment reflects mean air temperature.

We measured plant wax in leaves and soils along an environmental gradient in the Ecuadorian Andes. These data show how the wax composition changes as the plant material degrades in different environments. Local temperature is reflected in the wax despite the level degradation. The study results warrant further research into a possible causal relationship that may lead to the development of n-alkane patterns as a novel palaeoecological proxy.