Fertiliser Microdosing and Organic Amendments as an Integrated Soil Fertility Management Strategy: Evidence From On‐Farm Sorghum Trials in Burkina Faso
Yacouba Ouedraogo, J. Taonda, I. Sermé, B. Tychon, Jean‐Thomas Cornelis, H. Nacro, Charles L. Bielders
Soil use and management 2026 DOI: 10.1111/sum.70182 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational study; multi-site on-farm field trials Peer reviewed |
|---|---|
| Sample size | 225 |
| Population | Sorghum crops in on-farm trials across three provinces of Burkina Faso along a north-south climatic gradient |
| Duration | 2 years |
| Topics | Microdosing |
| Key findings | The highest sorghum yields occurred when fertiliser microdosing was combined with compost or compost with rock phosphate, but FM's yield gains were not improved by adding compost, compost-BP, or biochar relative to FM alone. FM with N-P-K 23-10-05 outperformed the conventional 14-23-14 blend in the south, and crop response to FM was strongly soil type-dependent. The authors conclude that macerated biochar and compost-BP plus FM are unsuitable for optimising smallholder sorghum production, and recommend combining FM with compost where sufficient compost is available. |
Abstract
Fertiliser microdosing (FM) is widely promoted in sub‐Saharan Africa as a means to improve fertiliser use efficiency in cereal crops. However, combining organic amendments with FM could further increase the agronomic efficiency of the latter because of possible synergies between both practices. This study therefore evaluated whether combining FM with organic amendments enhanced fertiliser use efficiency in sorghum crops and how local biophysical or management factors mediate this interaction. Over 2 years, 225 on‐farm trials were conducted across three provinces of Burkina Faso along a north–south climatic gradient. In the northern (Zandoma) and central (Oubritenga) provinces, eight treatments were tested at each site: FM (N‐P‐K 14–23‐14), hill‐placed compost, hill‐placed compost + FM, hill‐placed compost with rock phosphate (compost‐BP), hill‐placed compost‐BP + FM, hill‐placed biochar, hill‐placed biochar macerated with fertiliser, and control plots. In the Sissili province (south), compost‐BP was replaced by N‐P‐K 23‐10‐05. The highest sorghum yields were observed when FM was combined with compost or compost‐BP. However, yield gains attributable to FM (N‐P‐K 14‐23‐14) were not improved by adding compost, compost‐BP, or biochar compared to FM alone. In Sissili, FM with N‐P‐K 23‐10‐05 outperformed the conventional 14‐23‐14 formulation, highlighting the need to adapt fertiliser blends to agro‐climatic zones. Across all treatments, crop response to FM was strongly soil type‐dependent. In Zandoma, the driest province, it was observed that the residual effects of previous fertiliser applications affected yield response to FM. The results suggest that hill‐placement of macerated biochar or the combination of FM with compost‐BP are not suitable for optimising smallholder sorghum production. Combining FM with compost is recommended where sufficient compost is available. Otherwise, applying FM and compost in different fields or parts of fields is to be recommended. Further research is needed to explain the poor response to macerated biochar in Oubritenga and Zandoma.