Land use changes are an important anthropogenic perturbation that can cause soil degradation, but the impacts of land conversion from growing cereals to vegetables have received little attention. Using a combination of soil analyses from paired sites and data from farmer surveys, we found significant soil degradation in intensive vegetable cropping under paddy rice–oilseed rape rotation in southwestern China. This study may alert others to the potential land degradation in the subtropics.

Sedimentary rocks contain organic carbon that may end up as soil carbon. However, this source of soil carbon is overlooked and has not been quantified sufficiently. We analysed 10 m long sediment cores with three different sedimentary rocks. All sediments contain considerable amounts of geogenic carbon contributing 3 %–12 % to the total soil carbon below 30 cm depth. The low ¹⁴C content of geogenic carbon can result in underestimations of soil carbon turnover derived from ¹⁴C data.

Mineralogical combinations of aluminous clay and pedogenic Fe oxides revealed significant effects on soil structure and related organic carbon (OC) storage. The mineralogical combination resulting in the largest aggregate stability does not better preserve OC during conversion of forests into croplands. Structural changes in the direction of smaller mean weight diameters do not cancel out the stabilizing effect of soil minerals.

Forests store large amounts of carbon in soils. Implementing suitable measures to improve the sink potential of forest soils would require accurate data on the carbon stored in forest soils and a better understanding of the factors affecting this storage. This study showed that the prediction of soil carbon stock in Swedish forest soils can increase in accuracy when one divides a big region into smaller areas in combination with information collected locally and derived from satellites.

This study demonstrates the usability of fallout radionuclides ²³⁹Pu and ²⁴⁰Pu as a tool to assess soil degradation processes in tropical Africa, which is particularly valuable in regions with limited infrastructure and challenging monitoring conditions for landscape-scale soil degradation monitoring. The study shows no indication of soil redistribution in forest sites but substantial soil redistribution in cropland (sedimentation >40 cm in 55 years) with high variability.

We evaluated how sequestration of soil carbon changes over the long term after converting native grasslands into croplands and also from annual cropping into trees. Soil carbon was reduced by cropping but increased with tree planting. This decrease in carbon storage with annual cropping happened over centuries, while trees increase soil carbon over just a few decades. Growing trees in long-term croplands emerged as a climate-change-mitigating action, effective even within a person’s lifetime.

Soil greenhouse gas (GHG) fluxes were measured monthly from nitrogen (N), phosphorous (P), N and P, and control plots of the first nutrient manipulation experiment located in an African pristine tropical forest using static chambers. The results suggest (1) contrasting soil GHG responses to nutrient addition, hence highlighting the complexity of the tropical forests, and (2) that the feedback of tropical forests to the global soil GHG budget could be altered by changes in N and P availability.

In deeply weathered tropical rainforest soils of Africa, we found that patterns of soil organic carbon stocks differ between soils developed from geochemically contrasting parent material due to differences in the abundance of organo-mineral complexes, the presence/absence of chemical stabilization mechanisms of carbon with minerals and the presence of fossil organic carbon from sedimentary rocks. Physical stabilization mechanisms by aggregation provide additional protection of soil carbon.

How subsoil microorganisms respond to warming is largely unknown, despite their crucial role in the soil organic carbon cycle. We observed that the subsoil microbial community composition was more responsive to warming compared to the topsoil community composition. Decreased microbial abundance in subsoils, as observed in this study, might reduce the magnitude of the respiration response over time, and a shift in the microbial community will likely affect the cycling of soil organic carbon.

We use a holistic framework to analyze how agricultural policy in Germany affects the sustainability of soil management. We look at the adequacy of policy targets, objects (i.e. drivers of soil degradation), instruments, assumptions about farmers' behaviour, and the coherence among these four dimensions. We find deficits in each dimension, particularly object and instrument adequacy. Agricultural soil policy in Germany lacks depth and coherence, and the role of biomass demand is neglected.

This study found that the influence of argan trees on soil properties in southern Morocco is mostly limited to the area covered by the tree crown. However, the tree influences the bare soil outside the crown positively in specific directions because wind and water can move litter and soil particles from under the tree to the areas between the trees. These findings, based on soil samples around argan trees, could help structure reforestation measures.

We developed the Swiss mid-infrared spectral library and a statistical model collection across 4374 soil samples with reference measurements of 16 properties. Our library incorporates soil from 1094 grid locations and 71 long-term monitoring sites. This work confirms once again that nationwide spectral libraries with diverse soils can reliably feed information to a fast chemical diagnosis. Our data-driven reduction of the library has the potential to accurately monitor carbon at the plot scale.

Drought and flooding challenge agricultural systems and their management globally. Here we investigated the response of soils from long-term agricultural field sites with simple and diverse crop rotations to either drought or flooding. We found that irrespective of crop rotation complexity, soil and microbial properties were more resistant to flooding than to drought and highly resilient to drought and flooding during single or repeated stress pulses.

The central Mongolian forest steppe underlies a recent decline of forested area. We analysed the site and soil properties in the Khangai Mountains to identify differences between disturbed forest areas with and without regrowth of trees. More silty soils were found under areas with tree regrowth and more sandy soils under areas without tree regrowth. Due to the continental, semi-arid climate, soil properties which increase the amount of available water are decisive for tree regrowth in Mongolia.

Transfer of organic C from topsoil to deeper horizons and the water table is little documented, especially in equatorial environments, despite high primary productivity in the evergreen forest. Using column experiments with podzol soil and a percolating solution sampled in an Amazonian podzol area, we show how the C-rich Bh horizon plays a role in natural organic matter transfer and Si, Fe and Al mobility after a kaolinitic layer transition, thus giving insight to the genesis of tropical podzol.

Straw mulching is not always combined with no-till systems during conservation tillage. We explored the effects of long-term straw mulching on soil attributes with soil depths under a no-till system. Compared to straw removal, straw mulching had various effects on soil properties at different depths, the biggest difference occurring at the topsoil depth. Overall, straw mulch is highly recommended for use under the no-till system because of its benefits to soil fertility and bacterial abundance.

In this paper, we describe changes in desert soil bacterial diversity and function when two ecosystem engineers, shrubs and ant nests, in an arid environment are present. The results show that bacterial activity increases when there are ecosystem engineers and that their impact is non-additive. This is one of a handful of studies that investigated the separate and combined effects of ecosystem engineers on soil bacterial communities investigating both composition and function.

Through a laboratory incubation experiment, we investigated the spatial patterns of specific maximum heterotrophic respiration in tropical African mountain forest soils developed from contrasting parent material along slope gradients. We found distinct differences in soil respiration between soil depths and geochemical regions related to soil fertility and the chemistry of the soil solution. The topographic origin of our samples was not a major determinant of the observed rates of respiration.

As urban populations grow, soil sealing with impermeable surfaces will increase. At present there is limited knowledge on the effect of sealing on soil carbon and nutrients. We found that, in general, sealing reduced soil carbon and nutrients; however, where there were additions due to human activity, soil carbon and nutrients were increased. This suggests that there is a legacy soil carbon store in areas with an industrial past and highlights the influence of artefacts in urban soil.

Studies on soil organic carbon stock (SOCS) in the Sudano-Sahelian part of Cameroon are very rare. Organic C storage decreases with increasing latitude and more than 60 % of the SOCS is stored below the first 25 cm depth. In addition, a good correlation is noted between precipitation which decreases with increasing latitude and the total SOCS, indicating the importance of climate in the distribution of the total SOCS in the study area, which directly influence the productivity of the vegetation.

We present a soil mid-infrared library with over 1800 samples from central Africa in order to facilitate soil analyses of this highly understudied yet critical area. Together with an existing continental library, we demonstrate a regional analysis and geographical extrapolation to predict total carbon and nitrogen. Our results show accurate predictions and highlight the value that the data contribute to existing libraries. Our library is openly available for public use and for expansion.

This work delivers openly accessible and validated calibrations for diagnosing 26 soil properties based on mid-infrared spectroscopy. These were developed for four regions in Burkina Faso and Côte d'Ivoire, including 80 fields of smallholder farmers. The models can help to site-specifically and cost-efficiently monitor soil quality and fertility constraints to ameliorate soils and yields of yam or other staple crops in the four regions between the humid forest and the northern Guinean savanna.

Since the 20th century, human beings have released a large amount of reactive nitrogen by excessive application of nitrogen fertilizer, which resulted in enhanced greenhouse effect. It is not clear how the ecosystem nitrogen cycle evolves during global warming. In this study, we collected global data and used meta-analysis to reveal the response of nitrogen cycle to climate warming. The results show that the future climate warming can accelerate the process of ecosystem nitrogen cycle.

Open-cast mining increases soil erosion and transfer of sediment in river systems. Providing a methodology to better understand the sediment dynamic of these catchments is essential to manage this pollution. In this study, different tracers such as elemental geochemistry or colour properties were tested to trace and quantify the mining source contributions to the sediment inputs in the Thio River catchment, one of the first areas exploited for nickel mining in New Caledonia (i.e. since 1880).

Achieving global restoration targets requires scaling of context-specific restoration options on the ground. We implemented the Land Degradation Surveillance Framework in Rwanda to assess indicators of soil and land health, including soil organic carbon (SOC), erosion prevalence, infiltration capacity, and tree biodiversity. Maps of soil erosion and SOC were produced at 30 m resolution with high accuracy. These data provide a rigorous biophysical baseline for tracking changes over time.

Plant organs, such as leaves, contain a variety of chemicals that are eventually deposited into soil and can be useful for studying organic carbon cycling. We performed a systematic review of available data of one type of plant-derived chemical, n-alkanes, to determine patterns of degradation or preservation from the source plant to the soil. We found that while there was degradation in the amount of n-alkanes from plant to soil, some aspects of the chemical signature were preserved.

Biochar is purported to alter soil water dynamics and reduce nutrient loss when added to soils, though the mechanisms are often unexplored. We studied the ability of seven biochars to alter the soil chemical and physical environment. The flow of ammonium through biochar-amended soil was determined to be controlled through chemical affinity, and nitrate, to a lesser extent, through physical entrapment. These data will assist land managers in choosing biochars for specific agricultural outcomes.