Arbuscular mycorrhizal fungi (AMF) play a central role in enhancing nutrient uptake by plants, increasing resilience to biotic and abiotic stresses, and supporting proper functioning of tropical agroecosystems, such as cacao plantations. However, little is known about diversity and capacity of native strains in rhizospheres, as well as soil factors shaping AMF communities. This study aimed to assess (i) AMF diversity and abundance in cocoa rhizospheres and the relationship with soil chemical properties and climatic variables at seven distinct areas in Côte d’Ivoire, i.e., Adzope, Agnibilekrou, Azaguie, Biankouma, Ble, Bonon and Soubre; (ii) in-situ capacity of strains from these rhizospheres. Soil samples were collected in 66 cocoa plots and AMF spores were extracted and identified based on morphometric criteria. Part of soils was used for trap cultures, while another part was used for determination of chemical properties. Our findings indicate that fungal communities associated with cacao are dominated by families Glomeraceae and Acaulosporaceae. Before establishment of trap cultures, cacao rhizospheres showed highest spore abundance at Ble (103 ± 47 spores/100 g soil) and lowest abundance at Biankouma (47.3 ± 21.6 spores/100 g soil). AMF strains from Agnibilekrou and Biankouma soils showed highest quantitative sporulation capacity, whereas strains from Soubré soils exhibited strongest infective capacity. 18.49% of variance in AMF community is explained by soil chemical variables, whereas 5.32% is explained by climatic variables, with Mn, Zn, Cr, and precipitation as main drivers. This study highlighted that a clear understanding of AMF communities in cocoa rhizospheres is essential to facilitate the design of efficient soil and plant conservation strategies, thus ensuring the sustainability and long-term productivity of cocoa agroecosystems in Côte d’Ivoire.
Tag: agroecosystems
Temporal and spatial variability in photosynthetic activity of Vitellaria paradoxa in agroforestry parklands of Burkina Faso
This study investigated the temporal and spatial variation in photosynthetic activity of Vitellaria paradoxa (shea tree) growing in agroforestry parklands across two contrasting climatic zones of Burkina Faso. Measurements of chlorophyll fluorescence, chlorophyll content, leaf temperature, stomatal conductance, and environmental variables were conducted from April to December 2023 to assess physiological responses to climatic variability. Significant differences were observed between the northern and southern Sudanian phytogeographical zones, particularly in chlorophyll content, energy dissipation mechanisms, and photosynthetic performance. Trees in the more humid southern Sudanian zone exhibited higher chlorophyll content and better photosynthetic efficiency than those in the drier northern zone. Leaf temperature was strongly influenced by ambient temperature, while vapor pressure deficit and photosynthetically active radiation affected stomatal conductance and energy dissipation processes. The results demonstrate that V. paradoxa possesses physiological mechanisms that enable adaptation to changing environmental conditions, including regulation of heat dissipation, chlorophyll utilization, and gas exchange. These findings improve understanding of the ecophysiological resilience of shea trees under climate change and provide insights for sustaining agroforestry parklands in the Sudano-Sahelian region.
Understanding gendered aspirations, decision-making, and fruit tree preferences in Makueni County, Kenya
In Makueni County, Kenya, smallholder farmers face erratic rainfall, severe droughts, recurrent floods, and water scarcity due to climate change. Understanding farmers’ aspirations is therefore essential to ensuring that support is relevant and responsive. This study explored: (1) farmers’ aspirations for farm composition, particularly fruit tree species, and potential changes in response to market and climate shifts; (2) gender dynamics shaping fruit tree cultivation decisions; and (3) connections between cultivated species, aspirations, and decision-making across gender and age. Data collected via focus group discussions, semi-structured interviews and key informant interviews revealed a shift towards fruit-tree-based livelihoods, ostensibly offering improved food and income security and reduced labour. However, this shift, dominated by a few exotic species, may reduce farm- and landscape-scale species diversity. Decision-making was strongly gendered: men dominated species selection and management and controlled large-scale sales of higher-value fruit, owing to land ownership, knowledge and cultural norms, while women held greater power over small-scale sales, lower-value species and the income these generated. To foster equitable, resilient farming systems, we recommend inclusive, gender-responsive fruit tree production and management training. Transforming gender relations to amplify women’s voices in species selection could diversify fruit tree portfolios and lead to more equitable and biodiverse farming systems.
Indigenous practices in forest conservation
This chapter explores Indigenous knowledge systems and traditional practices in forest conservation in Sabah, Malaysia. It highlights how Indigenous communities manage natural resources through customary laws, spiritual beliefs, and practices such as rotational agriculture, resource-use restrictions, and community-based governance. The chapter emphasizes the importance of traditional knowledge, community mapping, and protocols in sustaining biodiversity and ecosystem services. While these practices contribute significantly to conservation, Indigenous communities face ongoing challenges related to land tenure insecurity, governance conflicts, cultural erosion, and limited recognition of customary rights in formal legal systems.
The ongoing journey of modelling intercropping systems: A conceptual resource sharing intercomparison from model developers and expert users
Context
The global shift toward sustainable agriculture has increased interest in using process-based models to design and optimize intercropping systems. However, these models differ fundamentally in how they represent trade-offs (competition for light, water, and nutrients) and synergies (facilitation, complementarity) in resource sharing between species. This conceptual variation creates uncertainty in model selection and application, particularly since most models were originally developed for monoculture and subsequently adapted for intercropping.
Objective
In this study, we describe how current crop models represent interspecies resource-sharing mechanisms, analyse their structural differences, and synthesize findings from existing validation studies to understand how their structural differences affect model performance. The models examined include APSIM (APSIM-Canopy, APSIM-Micromet, APSIM-Strip, APSIM-Alternating, APSIM-APSwim, APSIM-SoilArbitrator), DayCent, DSSAT-Mixed, DSSAT-MPI, LandscapeDNDC, LUCIA, MONICA, SIMPLACE Lintul5-Intercrop, STICS-Big-Leaf, STICS-Multilayer, and WaNuLCAS.
Methods
Through the Agricultural Model Intercomparison and Improvement Project (AgMIP) platform, we engaged with model developers and expert users to collect detailed information on how crop models represent intercropping systems using structured interviews and questionnaires. We then developed a framework that groups models by their core conceptual approaches to simulating resource sharing. Finally, we synthesize findings from existing quantitative validation studies to connect conceptual intercomparison to predictive performance across different intercrop characteristics and environments.
Results and Conclusions
Our analysis identifies six distinct conceptual approaches for simulating light sharing and four for belowground resource (water and nutrient) competition. Intercrop models show greater structural divergence in canopy than in belowground representation. Furthermore, competitive trade-offs (light, water, and nutrients) are widely represented while facilitative and other complex processes like N₂-fixation, plasticity (shoot and root), microclimate effects or hydraulic lift are often simplified or omitted. Our analysis of model validation studies reveals a critical trade-off: structurally complex models often perform well in simulating intercropping when calibration is done on sole crops, whereas simpler models require extensive intercrop-specific calibration to achieve better prediction performance. This distinction is vital for model application in data-scarce environments, as more complex architectures can leverage existing sole-crop data to effectively simulate intercrop systems. The classification of the structural resource capture differences in combination with the evaluated model performance analysis allowed us to devise an evidence-based model selection criteria framework useful also for for non-specialist, while the unique detailed description provided are highly valuable for the model research community.
Significance
This study establishes a conceptual framework that provides the necessary foundation for a meaningful quantitative intercomparison of intercrop models, as structural understanding enables the interpretation of numerical differences in model outputs. It also guides hypothesis testing, model choice, priorities in model development and improvements.
Interactions between regenerative strategies and edaphic, climatic and topographic factors mediate mitigation or exacerbation of soil and crop toxicity in global cadmium contaminated lands
Cadmium (Cd) contamination in agroecosystems is a global concern, due to its negative influence on soil health and crop performance. Regenerative strategies have been widely recognised as vital to improve soil quality and crop yields. Yet strategies are needed that also mitigate rather than exacerbate the impacts of Cd contamination. In this context, interactions between regenerative strategies, and edaphic, climatic and topographic factors are poorly understood. This study presents a meta-analysis with effect size statistics, evaluating the interactions between regenerative strategies (biochar, manure and compost), non- regenerative strategies (sewage-sludge and fertilizer), soil properties (pH, SOM and Cd levels), climatic factors (temperature and precipitation), and elevation. In acidic or high SOM soils, fertilizer increased Cd uptake by 50% to 76%. However, biochar or compost addition in these soils reduced Cd uptake. Under high Cd contamination, biochar application increased shoot biomass, but fertilizer application decreased shoot-biomass. The application of fertilizer or sewage-sludge under higher temperatures increased Cd uptake, whereas biochar reduced Cd uptake. At wet sites, fertilizer addition increased soil Cd accumulation. At high elevations, biochar was more effective than manure at reducing Cd accumulation. We conclude that there are complex interactions between regenerative strategies and environmental conditions; determining impacts on soil and crop health. The interactions between environmental factors and use of sewage-sludge or fertilizer could exacerbate soil and plant Cd toxicity. Regenerative strategies, especially biochar, could mitigate Cd toxicity in agroecosystems.
Can improved plant nutrition buffer against water-related yield losses in oil palm?
Oil palm is the main source of vegetable oil in the world, with Indonesia accounting for 60 % of global production. Maintaining stable oil palm yields amidst changing climate is important given the implications for processing mills, supply chains, and socio-economic outcomes. Using monthly yield data collected over 7–9 years from four fertilization trials in water-limited environments in Indonesia, we assessed the impact of plant nutrition on the stability of oil palm yield. Each trial included three fertilization treatments (low, standard practice, and high) leading to differences in plant nutritional status across treatments as determined using leaf tissue analysis. Average yield was 77 % higher in the high- versus low-fertilizer treatments (27.1 and 15.3 t ha⁻¹, respectively), with temporal yield variation driven by water stress and vapor pressure deficit. Improved plant nutrition increased the yield response to favorable weather, leading to a concomitant increase in absolute yield variation (standard deviation and inter-quartile range), but smaller relative variation (coefficient of variation and sustainable yield index). On the other hand, improving plant nutrition had little impact on yield during low-yielding cycles due to water limitation. Despite the key role of plant nutrition to sustain high oil palm yields, our study shows limited room to stabilize yield and/or avoid climate-related yield losses. On the other hand, our findings suggest that future yield improvement will depend more on reducing yield constraints under favorable conditions, which will require greater flexibility to adjust field and mill operations to the larger yield variation.
Impacts of land use change on ecosystem service degradation within a traditional circular agroecosystem: a case study of the Honghe Hani Rice Terraces
Amid ongoing socio–economic development and natural environmental changes, the paddy rice area within the Honghe Hani Rice Terraces has undergone substantial decline, resulting in significant imbalances within the agroecosystem. This study employs land use change mapping and ecosystem service evaluation models to assess the ecological impacts of land use changes on the agricultural system from 1990 to 2020. The findings reveal that the area of paddy rice decreased by a net total of 36.35 km2, representing a 24.83% reduction, with most of this area being converted into forest and cropland. Although forest expansion led to a 16.61% increase in carbon storage, the habitat quality declined overall due to the reduction in paddy rice areas. Specifically, the extent of lower-quality habitat areas expanded by 134.71 km2 (30.02%), while soil retention and water yield ecosystem services decreased by 14.43% and 11.74%, respectively. Areas exhibiting extremely high sensitivity to habitat degradation (32.71%), and geological hazards (38.82%) increased markedly, thereby posing substantial risks to the resilience of the terrace system. Conversely, the total area sensitive to soil erosion declined by 48.84%. These results demonstrate that land use change has adversely affected the traditional agroecosystem services of the Honghe Hani Rice Terraces. The study further proposes pathways for the optimization and conservation of traditional agroecosystem functions.
Influence of Eucalyptus camaldulensis Dehnh on the growth, productivity and physiology of three associated crops in the Sudano-Sahelian zone of Burkina Faso, West Africa
Eucalyptus camaldulensis Dehnh is an exotic species found in Sahel agroecosystems, often growing alongside annual crops. However, there is limited documentation regarding its ecological impacts on these crops. This study aims to assess the influence of eucalyptus on crop physiological traits and yield. To accomplish this, on-farm experiments were conducted over two years (2022 and 2023), employing a tree effect gradient called a gradient-based design with 4–7 replications for cowpea, millet, and sorghum. The experimental design included three plot locations based on their proximity to the eucalyptus trunk: one directly under the crown, another centred at 11 m, and a control plot situated 22 m away. Various parameters, such as height, relative chlorophyll content, leaf area index, photosynthetically active radiation, and yields of grain straw, were measured across all plots and years. Results from pairwise tests indicated significant differences among the plots for most parameters studied. Notably, plant height significantly decreased in proximity to eucalyptus (p < 0.000) throughout the two years. For relative chlorophyll content, the millet and sorghum in 2022 presented significant differences between plots located at 22 m and plots under the crown (p = 0.000). The photosynthetically active radiation indicated significant differences between the plot located at 22 m and the plot under the crown in cowpea, sorghum (2022 and 2023). Additionally, grain and straw yields were significantly lower near the eucalyptus in both years (p < 0.05). These findings suggest potential ecological risks associated with growing certain crops close to eucalyptus in the Sahel context.
Ecosystem Baseline Report. Ecosystem Baseline Assessment For The “Building Resilient Communities in Somalia (BRCiS) III” Programme
This ecosystem baseline assessment aims to provide a comprehensive and quantitative analysis of land health across 37 BRCiS III project areas, delineated based on the shared use of natural resources. Through an extensive ecosystem field data collection campaign, in combination with remote sensing and machine learning approaches, this assessment considers a variety of soil, vegetation, climate and social indicators to assess the ecosystem health from multiple dimensions. The objectives of this report are to provide a field-based assessment of the current state of ecosystem health at several BRCiS III project areas in Somalia and assess ecosystem health at the project area level based on vegetation, soil, climate and soil health indicators.