Lime and Dolomite Identified as Key Solutions to Sierra Leone’s Soil Acidity — Crop Researcher Reveals
By Alimamy Jalloh
Lansana Sesay, a leading crop productivity and soil researcher at the Rokupr Agricultural Crop Research Centre in Kambia District, has revealed that the application of lime or dolomite — along with essential nutrients such as magnesium and phosphorus — can significantly improve yields on Sierra Leone’s acidic farmlands.
According to Sesay, much of the country’s boli and swamp land soils measure below 7 on the pH scale, with readings as low as 3.3 to 3.7, making them strongly acidic. This acidity, he warned, is a major factor contributing to the country’s low crop productivity, especially in rice-growing areas.
“Acidic soils reduce the availability of essential nutrients such as calcium, magnesium, and phosphate minerals,” Sesay explained. “Without these, plants cannot develop optimally, and yields drop sharply.”
He noted that while some soils in Sierra Leone are alkaline, they are rare. The lack of thick vegetation cover, combined with low organic matter, further worsens acidity. Practices such as applying urea fertilizer without proper soil balancing can also increase soil hydrogen ion concentration, making the soil even more acidic.
Sesay emphasized that the issue is compounded by inadequate agricultural research and untimely delivery of planting materials and fertilizers.
“One acre of boli land should yield about 40 bushels of rice, but in reality, some farmers harvest only five bushels,” he lamented.
Farmers across the country have reported similar challenges.
Ibrahim Koroma, from Mayomra Village in Masiaka, said he sometimes harvests just one bushel of rice per season.
Mohamed Thaimu Kamara, from Kamasondo Chiefdom in Port Loko District, recounted losing his entire rice crop last year to flooding and erosion from the Little Scarcies River.
The World Bank’s 2023 Risk Assessment Report indicated a 35% increase in domestic rice production that year, yet warned that agriculture remains the primary livelihood for about 75% of rural households — two-thirds of whom live below the poverty line.
Sesay recommended a targeted approach to reversing soil acidity and boosting yields, including:
• Applying lime, dolomite, or other organic and chemical soil amendments.
• Using fertilizers rich in magnesium, phosphorus, and potassium sulphate (such as NPK 15:15 or NPK 20:20), depending on soil type.
• Increasing agricultural research and soil surveys before planting.
• Matching seed types to specific soil conditions.
• Ensuring timely delivery of seeds and fertilizers.
He urged policymakers, agricultural institutions, and farmers to work together to implement these measures, noting that without decisive action, Sierra Leone will struggle to achieve sustainable crop productivity and food security.
