Low-Cost Planting Precision for Smallholders: A Review of Low-tech Row-spacing Tools, Agronomic Outcomes and Input-efficiency
Inusah Najjiulai
Department of Agrobiotechnology, Institute of Agriculture, RUDN University, 117198, Moscow, Russia and Department of Agricultural and Biosystems Engineering, Kwame Nkrumah University of Science and Technology, PMB, Kumasi AK-039-5028, Ghana.
Funchious Paul Mensah
*
Department of Agrobiotechnology, Institute of Agriculture, RUDN University, 117198, Moscow, Russia and Department of Agricultural and Biosystems Engineering, Kwame Nkrumah University of Science and Technology, PMB, Kumasi AK-039-5028, Ghana.
Ampah-Korsah Jessica
Department of Agrobiotechnology, Institute of Agriculture, RUDN University, 117198, Moscow, Russia.
Bediako Linda
Department of Agrobiotechnology, Institute of Agriculture, RUDN University, 117198, Moscow, Russia.
Agyemang Robert
Department of Agrobiotechnology, Institute of Agriculture, RUDN University, 117198, Moscow, Russia.
Adjetey Ronald Sowah
Department of Agrobiotechnology, Institute of Agriculture, RUDN University, 117198, Moscow, Russia.
Mensah Godwin
Department of Agrobiotechnology, Institute of Agriculture, RUDN University, 117198, Moscow, Russia.
Ayitey Bless Kodzo
Department of Agrobiotechnology, Institute of Agriculture, RUDN University, 117198, Moscow, Russia.
Chonchorkor Bitembi
Department of Agrobiotechnology, Institute of Agriculture, RUDN University, 117198, Moscow, Russia.
*Author to whom correspondence should be addressed.
Abstract
Background and Aims: In sub-Saharan Africa and Asia, smallholder farmers—those who grow less than two hectares—produce up to 80% of the food consumed and around one-third of the world's food. Smallholder farmers in developing countries face significant challenges in achieving optimal crop establishment due to limited access to precision planting technologies. This systematic review synthesizes evidence on low-cost, low-tech row-spacing and planting tools designed for smallholder contexts, examining their agronomic outcomes, input-use efficiency, and socioeconomic implications.
Study Design: We searched multiple databases (Google Scholar, Scopus via SciSpace, PubMed) for studies published between 2014 and 2025, identifying 234 relevant papers.
Results: Our analysis reveals that low-cost planting tools—ranging from simple hand planters (US$5-50) to manual push seeders (US$50-150) and adapted two-wheel tractor implements (US$150-300)—can improve stand uniformity, reduce seed rates by 10-15%, decrease planting labor by 50-82%, and enable more efficient fertilizer placement. Yield responses are context-dependent, with wheat and maize showing gains of 10-40% under optimal conditions. However, adoption remains constrained by upfront costs, limited local manufacturing capacity, inadequate repair infrastructure, and insufficient training. Service delivery models—including custom hiring and equipment rental—show promise for overcoming ownership barriers.
Conclusion: Research gaps include limited long-term studies, insufficient gender-disaggregated data, and weak evidence on fertilizer-use efficiency gains. This review provides a comprehensive taxonomy of low-cost planting technologies, synthesizes agronomic and economic evidence, and identifies priority areas for future research and policy intervention.
Keywords: Precision planting, row spacing, seed metering, input efficiency, low-cost technology, agricultural mechanization