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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.

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 Ivory Coast, 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 in between the humid forest and the northern Guinean savanna.

Zinc deficiency is a widespread nutritional problem in human populations, especially in sub-Saharan Africa (SSA). Crop Zn depends in part on soil Zn. Zinc status of soils from the Amahara region, Ethiopia was quantified by measuring pseudo-total, available, soluble and isotopically exchangeable Zn and soil geochemical properties were assessed. Widespread phytoavailable Zn deficiency was observed. The results could be used to improve agronomic interventions to tackle Zn deficiency in SSA.

In this study, we show that the variation in a soil spectral library (SSL) can be used to predict soil carbon at new and very different locations. The importance of this finding is that it requires less time-consuming lab work than calibrating a new model for every local application while still remaining similarly accurate as local models. Furthermore, we show that this method even works for predicting (drained) peat soils using an SSL with mostly mineral soils containing much less total carbon.

We present a soil mid-infrared library with over 1,800 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 highly accurate predictions and highlight the value that our library contributes to existing data. Our library is openly available for public use and for expansion.

This paper aims to reconstruct Middle Bronze Age (MBA) land use practices in the north-western Alpine foreland (SW Germany, Hegau). We used a multi-proxy approach including biogeochemical proxies from colluvial deposits in the surrounding of a MBA settlement, onsite archaeobotanical and zooarchaeological data and offsite pollen data. From our data we infer land use practices such as ploughing, cereal growth, forest farming and use of fire that marked the beginning of major colluvial deposition.

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-metallic 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 provides additional protection of soil carbon.

Soil greenhouse gas (GHG) fluxes were measured monthly from nitrogen (N), phosphorous (P), N + 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 highlight the complexity of the tropical forests, (2) that the feedback of tropical forests to the global soil GHG budget could be altered by changes in N and P availability.

There is need in agriculture for detailed soil maps that carry quantitative information. Geophysics-based soil maps have the potential to deliver such products but their added value has not been fully investigated yet. In this study, we compare the use of a geophysics-based soil map with the use of two commonly available maps as input for crop growth simulations. The geophysics base product results in better simulations with improvements that depend on precipitations, soil, and crop type.

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.

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 as well as better understanding of factors affecting this storage. This study showed that the prediction of soil carbon stock in Swedish forests soils can gain in accuracy when one divides a big region into smaller areas in combination with information collected locally and those derived from satellites.

In deeply weathered tropical rainforest soils of Africa, we found that patterns of microbial processes differ between soils developed from geochemically contrasting parent materials due to differences in resource availability. Across investigated geochemical regions and soil depths, soil microbes were P-limited rather than N-limited. Topsoil microbes were more C-limited than their subsoil counterparts but inversely P-limited.

Particulate macronutrient concentrations were up to three-fold higher in a natural forest catchment compared to fertilized agricultural catchments. Although the particulate macronutrient concentrations were lower in the smallholder agriculture catchment, because of higher sediment loads from that catchment, the total particulate macronutrient loads were higher. Land management practices should be focused on agricultural land to reduce the loss of soil carbon and nutrients to the stream.