AWF Project in MLW Watershed, DRC Yamboyo LDSF Site: soil health results

The Maringa-Lopori-Wamba Landscape (MLW) in DRC encompasses a wide range of land cover types, including dense moist semi-deciduous alongside smallholder agricultural systems. Regional interventions aimed to increase productivity was conserving natural resources have lacked baseline information on soil and land health for making informed decisions. This initiative aimed to fill gaps related to biophysical constraints in order to inform decisions

Landscape-scale assessments of stable carbon isotopes in soil under diverse vegetation classes in East Africa : application of near-infrared spectroscopy

Stable carbon isotopes are important tracers used to understand ecological food web processes and vegetation shifts over time. However, gaps exist in understanding soil and plant processes that influence delta C-13 values, particularly across smallholder farming systems in sub-Saharan Africa. This study aimed to develop predictive models for delta C-13 values in soil using near infrared spectroscopy (NIRS) to increase overall sample size. In addition, this study aimed to assess the delta C-13 values between five vegetation classes. The Land Degradation Surveillance Framework (LDSF) was used to collect a stratified random set of soil samples and to classify vegetation. A total of 154 topsoil and 186 subsoil samples were collected and analyzed using NIRS, organic carbon (OC) and stable carbon isotopes. Forested plots had the most negative average delta C-13 values, -26.1aEuro degrees; followed by woodland, -21.9aEuro degrees; cropland, -19.0aEuro degrees; shrubland, -16.5aEuro degrees; and grassland, -13.9aEuro degrees. Prediction models were developed for delta C-13 using partial least squares (PLS) regression and random forest (RF) models. Model performance was acceptable and similar with both models. The root mean square error of prediction (RMSEP) values for the three independent validation runs for delta C-13 using PLS ranged from 1.91 to 2.03 compared to 1.52 to 1.98 using RF. This model performance indicates that NIR can be used to predict delta C-13 in soil, which will allow for landscape-scale assessments to better understand carbon dynamics

Land Degradation Surveillance Framework (LSDF): field guide

The field methods employed in the soil health component of the AfSIS (Africa Soil Information Service) project are referred to as the Land Degradation Surveillance Framework (LDSF). This field guide outlines field protocols for measuring indicators of the “health” of an ecosystem, including vegetation cover, structure and floristic composition, historic land use, visible signs of soil degradation, and soil physical characteristics. It is designed to provide a biophysical baseline at landscape level, and a monitoring and evaluation framework for assessing processes of land degradation and the effectiveness of rehabilitation measures over time

Including soil organic carbon into nationally determined contributions: Insights from Kenya

Healthy soils are the foundation of sustainable and regenerative food systems and provide several vital ecosystem services. Sequestering carbon in agricultural soils, for example, can have mutual benefits for climate change mitigation and adaptation, food and nutrition security, biodiversity, and water resilience. Despite these benefits, there are few policies that incentivize farmers to invest in maintaining and improving soil health. This policy brief highlights opportunities for the inclusion of soil health and soil organic carbon (SOC) into the Nationally Determined Contributions (NDCs) as a key step for governments to support farmers in investing in their soil. This activity builds on recent assessments including a paper that extensively reviewed the first-round of 184 NDCs concluding that only 28 countries referred to SOC, peatlands or wetlands (1). This review and the subsequent interviews with experts (n=8) indicated the importance of understanding the impact of land management on SOC storage and dynamics (1). As a follow-up, Rose et al (2) focused on the updated NDCs and found that the number of countries that included SOC in their updated NDC increased compared to the first-round NDC process (2). This review also highlighted that 19 countries highlighted the need for financing for SOC and related measures (2)

Including soil organic carbon into nationally determined contributions: Insights from Zambia

Healthy soils are the foundation of sustainable and regenerative food systems and provide several vital ecosystem services. Sequestering carbon in agricultural soils, for example, can have mutual benefits for climate change mitigation and adaptation, food and nutrition security, biodiversity, and water resilience. Despite these benefits, there are few policies that incentivize farmers to invest in maintaining and improving soil health. This policy brief highlights opportunities for the inclusion of soil health and soil organic carbon (SOC) into the Nationally Determined Contributions (NDCs) as a key step for governments to support farmers in investing in their soil. We interviewed key informants involved in the NDC process to understand the process for the developing the NDC targets and investigated reasons why policy makers did or did not include soil in these targets

Including soil organic carbon into nationally determined contributions: Insights from Senegal

Healthy soils are the foundation of sustainable and regenerative food systems and provide several vital ecosystem services Sequestering carbon in agricultural soils, for example, can have mutual benefits for climate change mitigation and adaptation, food and nutrition security, biodiversity, and water resilience. Despite these benefits, there are few policies that incentivize farmers to invest in maintaining and improving soil health. This policy brief highlights opportunities for the inclusion of soil health and soil organic carbon (SOC) into the National Determined Contributions (NDC) as a key step for governments to support farmers to invest in their soil. We interviewed key informants involved in the NDC process to understand the process for the developing the NDC targets and investigated reasons why policy makers did or did not include soil in these targets

Including soil organic carbon into nationally determined contributions: Insights from Mali

Healthy soils are the foundation of sustainable and regenerative food systems and provide several vital ecosystem services Sequestering carbon in agricultural soils, for example, can have mutual benefits for climate change mitigation and adaptation, food and nutrition security, biodiversity, and water resilience. Despite these benefits, there are few policies that incentivize farmers to invest in maintaining and improving soil health. This policy brief highlights opportunities for the inclusion of soil health and soil organic carbon (SOC) into the National Determined Contributions (NDC) as a key step for governments to support farmers to invest in their soil. This activity builds on recent assessments including a paper that extensively reviewed the first-round of 184 NDCs concluding that only 28 countries referred to SOC, peatlands or wetlands (Wiese et al., 2021). This review and the subsequent interviews with experts (n=5) indicated the importance of understanding the impact of land management on SOC storage and dynamics (Wiese et al., 2021). As a follow-up, Rose et al (2022) focused on the updated NDCs and found that the number of countries that included SOC in their updated NDC increased compared to the first-round NDC process (Rose et al., 2022). This review also highlighted that 19 countries highlighted the need for financing for SOC and related measures (Rose et al., 2022)

Including soil organic carbon into nationally determined contributions: Insights from Ghana

Healthy soils are the foundation of sustainable and regenerative food systems and provide several vital ecosystem services. Sequestering carbon in agricultural soils, for example, can have mutual benefits for climate change mitigation and adaptation, food and nutrition security, biodiversity, and water resilience. Despite these benefits, there are few policies that incentivize farmers to invest in maintaining and improving soil health. This policy brief highlights opportunities for the inclusion of soil health and soil organic carbon (SOC) into the National Determined Contributions (NDC) as a key step for governments to support farmers to invest in their soil. This activity builds on recent assessments including a paper that extensively reviewed the first-round of 184 NDCs concluding that only 28 countries referred to SOC, peatlands or wetlands (Weise et al., 2021). This review and the subsequent interviews with experts (n=8) indicated the importance of understanding the impact of land management on SOC storage and dynamics (Weise et al., 2021). As a follow-up, Rose et al (202) focused on the updated NDCs and found that the number of countries that included SOC in their updated NDC increased compared to the first-round NDC process (Rose et al., 2021). This review also highlighted that 19 countries highlighted the need for financing for SOC and related measures (Rose et al., 2021)

Controls on timescales of soil organic carbon persistence across sub-Saharan Africa

Given the importance of soil for the global carbon cycle, it is essential to understand not only how much carbon soil stores but also how long this carbon persists. Previous studies have shown that the amount and age of soil carbon are strongly affected by the interaction of climate, vegetation, and mineralogy. However, these findings are primarily based on studies from temperate regions and from fine-scale studies, leaving large knowledge gaps for soils from understudied regions such as sub-Saharan Africa. In addition, there is a lack of data to validate modeled soil C dynamics at broad scales. Here, we present insights into organic carbon cycling, based on a new broad-scale radiocarbon and mineral dataset for sub-Saharan Africa. We found that in moderately weathered soils in seasonal climate zones with poorly crystalline and reactive clay minerals, organic carbon persists longer on average (topsoil: 201 ± 130 years; subsoil: 645 ± 385 years) than in highly weathered soils in humid regions (topsoil: 140 ± 46 years; subsoil: 454 ± 247 years) with less reactive minerals. Soils in arid climate zones (topsoil: 396 ± 339 years; subsoil: 963 ± 669 years) store organic carbon for periods more similar to those in seasonal climate zones, likely reflecting climatic constraints on weathering, carbon inputs and microbial decomposition. These insights into the timescales of organic carbon persistence in soils of sub-Saharan Africa suggest that a process-oriented grouping of soils based on pedo-climatic conditions may be useful to improve predictions of soil responses to climate change at broader scales

AFRICLIM: high-resolution climate projections for ecological applications in Africa (https://www.york.ac.uk/environment/research/kite/resources/)

A growing body of research shows the importance of land use/cover change (LULCC) on modifying the Earth system. Land surface models are used to stimulate land–atmosphere dynamics at the macroscale, but model bias and uncertainty remain that need to be addressed before the importance of LULCC is fully realized. In this study, we propose a method of improving LULCC estimates for land surface modeling exercises. The method is driven by projectable socio-ecological geospatial predictors available seamlessly across sub-Saharan Africa and yielded continuous (annual) estimates of LULCC at 5 km  ×  5 km spatial resolution. The method was developed with 2252 sample area frames of 5 km  ×  5 km consisting of the proportion of several land cover types in Kenya over multiple years. Forty-three socio-ecological predictors were evaluated for model development. Machine learning was used for data reduction, and simple (functional) relationships defined by generalized additive models were constructed on a subset of the highest-ranked predictors (p ≤ 10) to estimate LULCC. The predictors explained 62 and 65 % of the variance in the proportion of agriculture and natural vegetation, respectively, but were less successful at estimating more descriptive land cover types. In each case, population density on an annual basis was the highest-ranked predictor. The approach was compared to a commonly used remote sensing classification procedure, given the wide use of such techniques for macroscale LULCC detection, and outperformed it for each land cover type. The approach was used to demonstrate significant trends in expanding (declining) agricultural (natural vegetation) land cover in Kenya from 1983 to 2012, with the largest increases (declines) occurring in densely populated high agricultural production zones. Future work should address the improvement (development) of existing (new) geospatial predictors and issues of model scalability and transferability