Getting our Soil Right for Successful Vegetable Farming

Vegetable farming not only boosts food security but also promotes healthier, more sustainable diets. 

In our view, successful vegetable farming is a function of both productivity and a wide variety. 

Take tomatoes, one of Nigeria’s most valuable crops and a key ingredient in jollof rice. The average yield in Nigeria is just 3.91 tonnes per hectare—less than a tenth of the global average of 40 tonnes per hectare. In simple terms, for every ten tomatoes a farmer outside Nigeria can produce on the same amount of land, a Nigerian farmer can barely produce one. Improving this requires focused efforts, starting with improving soil health—a critical foundation for agricultural success.

This article explores the fundamentals of soil for vegetable farming, providing insights and practical tips to help farmers and gardeners make informed decisions and cultivate healthy, productive crops.

So, what is healthy soil?

Healthy soil serves as the foundation of successful farming. The FAO’s position is that healthy soil has the capacity  to function as a living system, sustaining plant and animal productivity, maintaining or enhancing water and air quality, and promoting overall health within ecosystem boundaries.

Key attributes of healthy soil include: 

1. Physical Properties: A well-structured composition that allows for good aeration, drainage, and water retention. This includes a crumbly texture with adequate pore spaces that facilitate the movement of water, air, and nutrients to plant roots.

2. Chemical Properties: A balanced array of essential nutrients—such as nitrogen, phosphorus, potassium, calcium, and magnesium, with a pH typically within the range of 6.0 to 7.5.

3. Biological Activity: Rich in diverse microorganisms and fauna that play critical roles in nutrient cycling, disease suppression, and organic matter decomposition. This biological activity enhances soil fertility and structure while promoting plant health.

4. Organic Matter Content: High levels of organic matter improve the soil's physical structure, enhance its nutrient-holding capacity, and increase its ability to retain moisture. 

   
   
   
   

Nigeria’s Soil Status

Research indicates that soil in Nigeria generally has a light texture and a low cation exchange capacity (CEC), which can make nutrient retention challenging. In many regions, clay content ranges from 9% to 43%, with over 60% of the land having clay levels below 15%. Compared to global agricultural soil with higher clay content and better nutrient retention, this presents an opportunity to enhance soil fertility through targeted interventions.  

According to the FAO, Nigerian soil loses an average of 24 kg of nutrients per hectare annually, increasing to 48 kg in recent years due to factors such as erosion, organic matter depletion, and insufficient replenishment.

Fertiliser usage in Nigeria is also relatively low, at about 10 kg per hectare compared to the global average of 90 kg.  

These challenges can be effectively addressed with practical soil management strategies, offering a pathway to improved agricultural productivity and long-term sustainability.

Strategies for Enhancing Soil Productivity

The Nigerian government has introduced the Nigeria Farmers' Soil Health Card Scheme (NFSHCS) to boost agricultural productivity by providing farmers with Soil Health Cards detailing their soil's nutrient status, pH, and organic content.

While awaiting full implementation, we encourage farmers to adopt these soil health strategies to sustain and enhance productivity: 

1. Soil Testing and Management: Test your soil regularly to identify nutrient levels, pH, and texture. This allows you to apply the right amount of fertilisers and amendments tailored to your farm’s needs. You can get your soil tested at Agricultural research institutes like the Cocoa Research Institute of Nigeria (CRIN), the International Institute of Tropical Agriculture (IITA)  and at departments of Soil Sciences in Universities, like University of Ibadan (UI). 

2. Use of Organic Fertilisers: Incorporate organic matter like compost, animal manure, or crop residues into the soil to enhance structure and microbial activity.

3. Crop Rotation and Diversification: Rotate crops with different nutrient demands (e.g., grow beans after maize) to maintain soil fertility and break pest cycles.

4. Adoption of Conservation Agriculture: Reduce tillage, use cover crops, and retain crop residues to protect the soil and prevent erosion, as well as increase water retention.

5. Irrigation Management: Use drip irrigation or other water-saving techniques to provide consistent moisture without overwatering.

In conclusion, the key to successful vegetable farming in Nigeria lies in understanding and improving soil health.

By embracing strategies like regular soil testing, the use of organic fertilisers, crop rotation, conservation agriculture, and efficient irrigation, Nigerian farmers can address soil fertility challenges and boost productivity. Focusing on soil care will not only enhance crop yields but also ensure a sustainable future for agriculture, helping to meet food security goals.