Abstract
Conservation agriculture (CA) is widely promoted for its potential to support agroecological intensification in sub-Saharan Africa, yet adoption among smallholder farmers remains limited, partly due to the high labour demands of manual and conventional animal draught (CAD) practices. Mechanised conservation agriculture (MCA), enabled by low-cost two-wheel tractor technologies, offers a promising solution, though comparative field evidence under smallholder conditions remains scarce. This study investigated the agronomic and labour performance of MCA systems relative to CAD-based practices, focusing on maize and common bean production in Zimbabwe. On-farm trials were conducted across 94 farms over two consecutive seasons (2018–2019 and 2019–2020) under typical smallholder management conditions. MCA significantly outperformed CAD practices across both crops. Grain yields increased by 1.26 t/ha (66%) for maize and 0.9 t/ha (82%) for common bean (P < 0.001). Labour requirements were reduced by 124.6 person-hours/ha (a 5.55-fold reduction) for maize and 99.7 person-hours/ha (a 3.34-fold reduction) for common bean under MCA (P < 0.001). Agronomic indicators (including crop emergence, grain yield, and labour inputs) were assessed using ANOVA and generalized linear mixed models (GLMMs) to account for variability across farms and treatments. Fuel consumption under MCA averaged 5.2 L/ha for maize and 7.1 L/ha for common bean, representing a recurrent cost. However, the value of labour saved relative to fuel expenditure favoured MCA by approximately 8:1 for maize and 5:1 for common bean, indicating strong economic viability. Capital costs of equipment nonetheless remain a barrier to individual ownership. Study limitations include its short duration and context-specific conditions, which may constrain generalisability. Long-term, multi-location research across diverse agroecological zones is needed to further validate these findings. This study provides robust field-based evidence that MCA can substantially reduce drudgery, improve crop productivity, and enhance livelihoods in African smallholder farming systems.
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Claims 8
Claim · model-written summary
MCA increased maize grain yield by 1.26 t/ha compared with CAD-based practices.
- Treatment
- MCAe0
- Outcome
- Grain yieldse1
- Direction
- increasede1
- Value
- 1.26 t/hae1
- Comparator
- CAD-based practicese0
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This study investigated the agronomic and labour performance of MCA systems relative to CAD-based practices, focusing on maize and common bean production in Zimbabwe”
e1“Grain yields increased by 1.26 t/ha (66%) for maize and 0.9 t/ha (82%) for common bean (P < 0.001)”
Claim · model-written summary
MCA increased common bean grain yield by 0.9 t/ha compared with CAD-based practices.
- Taxon
- common bean
Phaseolus vulgarise1 - Treatment
- MCAe0
- Outcome
- Grain yieldse1
- Direction
- increasede1
- Value
- 0.9 t/hae1
- Comparator
- CAD-based practicese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This study investigated the agronomic and labour performance of MCA systems relative to CAD-based practices, focusing on maize and common bean production in Zimbabwe”
e1“Grain yields increased by 1.26 t/ha (66%) for maize and 0.9 t/ha (82%) for common bean (P < 0.001)”
Claim · model-written summary
MCA reduced maize labour requirements by 124.6 person-hours/ha compared with CAD-based practices.
- Treatment
- MCAe0
- Outcome
- Labour requirementse2
- Direction
- reducede2
- Value
- 124.6 person-hours/hae2
- Comparator
- CAD-based practicese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This study investigated the agronomic and labour performance of MCA systems relative to CAD-based practices, focusing on maize and common bean production in Zimbabwe”
e2“Labour requirements were reduced by 124.6 person-hours/ha (a 5.55-fold reduction) for maize and 99.7 person-hours/ha (a 3.34-fold reduction) for common bean under MCA (P < 0.001)”
Claim · model-written summary
MCA reduced common bean labour requirements by 99.7 person-hours/ha compared with CAD-based practices.
- Taxon
- common beanPhaseolus vulgarise2
- Treatment
- MCAe0
- Outcome
- Labour requirementse2
- Direction
- reducede2
- Value
- 99.7 person-hours/hae2
- Comparator
- CAD-based practicese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This study investigated the agronomic and labour performance of MCA systems relative to CAD-based practices, focusing on maize and common bean production in Zimbabwe”
e2“Labour requirements were reduced by 124.6 person-hours/ha (a 5.55-fold reduction) for maize and 99.7 person-hours/ha (a 3.34-fold reduction) for common bean under MCA (P < 0.001)”
Claim · model-written summary
Fuel consumption under MCA averaged 5.2 L/ha for maize.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“Fuel consumption under MCA averaged 5.2 L/ha for maize and 7.1 L/ha for common bean, representing a recurrent cost”
Claim · model-written summary
Fuel consumption under MCA averaged 7.1 L/ha for common bean.
- Taxon
- common beanPhaseolus vulgarise3
- Treatment
- MCAe3
- Outcome
- Fuel consumptione3
- Value
- 7.1 L/hae3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e3“Fuel consumption under MCA averaged 5.2 L/ha for maize and 7.1 L/ha for common bean, representing a recurrent cost”
Claim · model-written summary
The value of labour saved relative to fuel expenditure favoured MCA by about 8:1 for maize.
- Treatment
- MCAe4
- Outcome
- the value of labour savede4
- Direction
- higherinferrede4
- Value
- 8:1e4
- Comparator
- fuel expendituree4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“the value of labour saved relative to fuel expenditure favoured MCA by approximately 8:1 for maize and 5:1 for common bean”
Claim · model-written summary
The value of labour saved relative to fuel expenditure favoured MCA by about 5:1 for common bean.
- Taxon
- common beanPhaseolus vulgarise4
- Treatment
- MCAe4
- Outcome
- the value of labour savede4
- Direction
- higherinferrede4
- Value
- 5:1e4
- Comparator
- fuel expendituree4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e4“the value of labour saved relative to fuel expenditure favoured MCA by approximately 8:1 for maize and 5:1 for common bean”
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