Understanding the State of Kenya’s Soils: Insights from the Soil Atlas

1. What is the current state of soils in Kenya?

Kenya is facing a serious soil degradation crisis that threatens agricultural productivity and food security. According to the Soil Atlas of Kenya (pp. 12–13), over 40% of East Africa’s soils are degraded. In Kenya alone, an estimated 26 tons of soil per hectare are lost annually due to erosion. Furthermore, 40% of the country’s irrigated land is affected by salinization, rendering large portions of it unproductive.

Key factors contributing to soil degradation include:

• Soil erosion – Caused by deforestation, unsustainable farming practices, and climate change.
• Decline in soil fertility – Driven by widespread soil acidification and nutrient depletion.
• Over-reliance on synthetic fertilizers – The Soil Atlas (pp. 28–29) highlights how dependence on chemical inputs often overlooks the root causes of nutrient loss.
• Climate change impacts – Droughts and floods worsen soil degradation (pp. 16–17).

Economic Impact:
The United Nations Convention to Combat Desertification (UNCCD, 2017) estimates that soil degradation costs Kenya billions annually in lost productivity, affecting food systems, rural livelihoods, and economic stability.

2. What are the causes of land degradation in Kenya?

Kenya’s once-fertile lands have deteriorated due to a combination of natural and human-induced factors:

• Deforestation and unsustainable land use – Clearing forests for agriculture disrupts soil structure and increases erosion.
• Intensive farming without conservation practices – Continuous cultivation depletes nutrients and damages soil integrity.
• Overgrazing – Excessive grazing exposes soil to erosion.
• Land grabbing and large-scale farming – As highlighted in the Soil Atlas (pp. 26–27), commercial land acquisitions displace smallholder farmers, leading to unsustainable expansion.
• Salinization and poor irrigation – Affects 40% of irrigated land (pp. 12–13).
• Climate change – Increased frequency of droughts and floods accelerates land degradation (pp. 16–17).

3. What parameters are used to classify soils?

Soils are classified based on a combination of physical, chemical, and biological properties:

• Texture – Proportions of sand, silt, and clay.
• Structure – Arrangement of soil particles.
• pH level – Acidity or alkalinity of the soil.
• Nutrient content – Levels of nitrogen (N), phosphorus (P), and potassium (K).
• Drainage capacity – Ability to retain and transmit water.
• Organic matter content – Crucial for fertility and microbial life.

According to the Soil Atlas (pp. 14–15), Kenya’s soils are highly diverse, requiring location-specific management strategies.

4. What soil characteristics are essential for profitable farming?

Profitable and sustainable farming depends on soil that supports healthy plant growth, effective nutrient cycling, and resilience to environmental stress. This balance depends on:

• Soil structure – Good structure promotes root development, water retention, and aeration. Loamy soils are ideal, while compacted soils restrict root growth and reduce yields.
• Soil chemistry – The right nutrient balance and pH levels (generally between 5.5 and 7.0) are vital. Acidic soils may need liming, while alkaline soils can cause micronutrient deficiencies.
• Cation Exchange Capacity (CEC) – Indicates the soil’s ability to retain and supply nutrients. Soils rich in organic matter and clay tend to be more fertile.
• Soil biology – Healthy soils host beneficial microbes, fungi, and earthworms that support nutrient cycling. Nitrogen-fixing bacteria (e.g., Rhizobium) and mycorrhizal fungi help improve nutrient availability.

As emphasized in the Soil Atlas (pp. 28–29), maintaining these characteristics through regular soil testing, organic amendments, and conservation practices is key to long-term agricultural success. Neglecting soil health leads to declining yields, greater dependence on synthetic inputs, and reduced profitability.

5. How was the Soil Atlas developed?

The Soil Atlas of Kenya was developed through a collaborative, expert-led process involving scientists, practitioners, and policymakers. Each chapter was authored by specialists, ensuring scientific accuracy, contextual relevance, and practical insights grounded in Kenya’s agricultural realities.

6. Who is the target audience and why?

The Soil Atlas is intended for a broad audience, including:

• Farmers – To raise awareness of soil health and sustainable practices.
• Policymakers – To inform land and agricultural policies.
• Researchers – To guide scientific studies and soil conservation strategies.
• Environmental organizations – To advocate for soil and biodiversity protection.

By engaging both practitioners and decision-makers, the Atlas supports evidence-based interventions to restore soil health and strengthen food systems.

7. What measures can help replenish degraded soils?

Effective soil restoration practices include:

• Agroforestry – Integrating trees with crops improves soil structure and fertility.
• Organic farming – Reduces chemical input dependence and enhances biodiversity.
• Cover cropping and crop rotation – Helps maintain soil nutrients and control pests.
• Minimum tillage – Reduces soil disturbance and promotes organic matter retention.
• Soil moisture conservation – Techniques like mulching help retain water and protect soil.

8. How is technology being used to improve soil health?

Technology is playing an increasingly vital role in soil regeneration:

• Precision agriculture – Utilises satellite imagery, drones, and soil sensors for real-time moisture, nutrients, and organic matter monitoring.
• AI-driven platforms – Offer customized recommendations based on soil data and climate patterns.
• Biological innovations – Biofertilizers and microbial inoculants containing nitrogen-fixing bacteria and fungi enhance soil health naturally.

When combined with agroecological practices, these technologies help reduce chemical input use, improve productivity, and restore degraded soils. As highlighted in the Soil Atlas, blending modern science with indigenous knowledge is essential for sustainable farming.

9. Who are the key collaborators behind the Soil Atlas?

The development of the Soil Atlas involved a range of partners, including

• Government agencies – Such as the Ministry of Agriculture.
• Research institutions – including KALRO.
• International organisations – Like ICRAF and FAO.
• Local NGOs and farmer groups—who brought grassroots perspectives and field experience.

10. What lessons have been learned from the development of the Soil Atlas?

Key takeaways include:

• Soil health is foundational to food security and livelihoods.
• Policy responses must address the root causes of degradation.
• Community involvement is critical to success.
• Combining traditional knowledge with modern science yields more sustainable outcomes.

11. What challenges remain?

Despite significant progress, several challenges persist:

• Limited funding for soil health initiatives.
• Slow policy implementation at the local and national levels.
• Climate change impacts such as drought and flooding.
• Lack of awareness and training among farmers.
• Overuse of synthetic fertilisers damages long-term soil health.

Addressing these issues will require stronger policies, increased investment, and robust public-private partnerships.

This piece was published by the Seeds of Gold on 7th July