Assessing the impact of agroforestry practices on carbon sequestration and soil health in smallholder farms under varying climate scenarios.

Project Abstract

This study investigates how agroforestry interventions influence carbon sequestration and soil health across smallholder farms subjected to diverse climate scenarios, integrating agronomic, ecological, and socio-economic perspectives to generate actionable insights for sustainable land management. We quantify above- and below-ground carbon stocks before and after the establishment of agroforestry systems that combine multipurpose tree species with major staple crops in two distinct agro-ecological zones, representing varying rainfall regimes, temperature patterns, and extreme event frequencies. A paired-plot design is employed to control for baseline variability, with continuous monitoring over three to five years to capture short- and medium-term dynamics of soil organic carbon (SOC), soil microbial activity, aggregate stability, and erosion resistance, alongside litterfall inputs, root biomass distribution, and mycorrhizal associations. Soil health is evaluated through a suite of indicators, including pH, cation exchange capacity, nutrient mineralization rates, enzyme activities, and soil water retention characteristics, complemented by remote sensing-derived, landscape-scale carbon flux estimates. The study also assesses changes in soil microbiome composition using high-throughput sequencing to elucidate functional shifts associated with diversified canopy systems, litter quality, and root exudates under different climate stressors. Climate scenarios are simulated using downscaled regional climate models to project future impacts on tree-crop interactions, evapotranspiration, and soil moisture regimes, enabling scenario-based risk assessment for productivity and carbon gain. Socio-economic surveys and farmer interviews are integrated to evaluate adoption determinants, labor requirements, cost-benefit trade-offs, and perceived resilience to climate variability, thereby identifying policy-relevant barriers and incentives for scaling agroforestry adoption. A mixed-methods analytical framework combines generalized linear mixed models, structural equation modeling, and spatial analysis to disentangle the direct and indirect pathways through which agroforestry affects carbon stocks and soil health, while accounting for farm heterogeneity, management practices, and climate uncertainty. Expected outcomes include (i) robust estimates of carbon sequestration potential per hectare for different agroforestry configurations under specified climate scenarios, (ii) improvements in SOC pools and soil biological activity, (iii) enhanced soil structure and nutrient cycling contributing to sustained yields, and (iv) practical guidelines for selecting tree-species combinations, planting densities, and management practices that optimize both climate resilience and soil health. The research aims to inform farmers, extension services, and policymakers on scalable agroforestry strategies that deliver co-benefits for climate mitigation, soil fertility, and livelihoods in smallholder agricultural systems facing increasing climate variability.

Project Overview

What This Project Is About

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A plain-language overview of how integrating trees with crops and livestock on small farms can affect soil health and the amount of carbon stored in the land, and how these effects change under different climate conditions. The project looks at practical agroforestry setups, such as shade trees, windbreaks, and multi-species plantings, and how they influence soil quality and carbon capture over time. It also considers everyday farming practices on smallholder plots and how they interact with climate variability.

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The Problem It Addresses

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Smallholder farmers often face soil degradation and limited carbon storage, which can worsen under climate change. There is a need to understand which agroforestry practices offer reliable soil health benefits and higher carbon sequestration, while remaining affordable and practical for small farms. This project fills gaps in evidence about how different tree-crop arrangements perform under varying rainfall and temperature patterns.

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Objectives of the Project

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1. Assess how different agroforestry setups affect soil health indicators (e.g., organic matter, soil nutrients, moisture).
2. Measure changes in above- and below-ground carbon stocks under various climate scenarios.
3. Compare outcomes between traditional crops with and without tree components on smallholder plots.
4. Identify practical agroforestry designs that maximize soil benefits and carbon storage within budget constraints.

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What You Will Do Step by Step

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1. Review literature to understand common agroforestry practices and soil carbon concepts.
2. Select representative smallholder sites and set up simple agroforestry treatments.
3. Collect soil samples periodically to measure organic matter, nutrients, and moisture.
4. Estimate carbon stocks using accessible field methods and/or simple models.
5. Analyze data to compare treatments and assess climate-related differences.
6. Interpret results in light of farmer practicality and cost.

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Expected Outcome

A practical set of agroforestry recommendations that improve soil health and increase carbon storage on smallholder farms, with guidance on which designs perform best under different climate conditions and budgets.