Dense planting enhances grain yield and profitability in low-yielding paddy fields of Sub-Saharan Africa
Related Research Project
Africa rice farming system
Country
Madagascar
Description
Rice yields in Sub-Saharan Africa (SSA) average 2.1 t ha−1, which is significantly lower than in other regions. Many smallholder farmers in SSA face economic constraints that limit their access to essential resources for improving yields, such as irrigation facilities, chemical fertilizers, and high-quality seeds. Optimizing planting density is a technique that smallholder farmers can implement on their own without these external inputs.
The effects of planting density have been extensively studied in irrigated rice fields with relatively high yield levels exceeding 5 t ha−1. However, no experimental studies have systematically examined how variations in planting density impact rice yields in low-yielding paddy fields (<5 t ha−1) commonly found in SSA.
This study was conducted in Madagascar, where low-yielding paddy fields are widespread. We examined the effects of two planting density treatments: the standard planting density of 25–26.7 hills m−2 (Standard) and a doubled density of 50–53.3 hills m−2 (Dense) using a common variety (X265) in a range of 38 environmental conditions. Additionally, based on household surveys of 356 farmers across 60 villages, we estimated the economic benefits of optimizing planting density by calculating the costs associated with seeds and labor, as well as the revenue gains from increased yields.
The results demonstrated that the dense planting had significantly and consistently higher yields than standard planting by 0.4 t ha−1 in the yield range of 1.8 and 4.6 t ha−1 while no advantage was detected when the yield was high at 5.5 t ha−1 or extremely low at < 1.3 t ha−1 (Fig. 1). In the yield range of 1.8 and 4.6 t ha−1, dense planting boosted initial light interception (Fig. 2), and the cumulative light interception from transplanting to maturity was closely correlated with the grain yield (Fig. 3). A household survey identified that the added seed and labor costs for doubling transplanting density from Standard to Dense were 58,000–62,000 MGA ha−1 and 66,000–71,000 MGA ha−1, respectively (Table 1). The additional benefit from the yield gain of 0.4 t ha−1 was estimated at 441,000 MGA ha−1, which exceeded 3 times the sum of added seed and labor costs for doubling planting densities. The study provided a practical and impactful strategy for increasing rice yields of smallholder farmers in SSA.
Figure, table
- Research project
- Program name
- Term of research
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FY2017-2024
- Responsible researcher
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Tsujimoto Yasuhiro ( Crop, Livestock and Environment Division )
ORCID ID0000-0001-7738-9913KAKEN Researcher No.: 20588511Ozaki Ryosuke ( Social Sciences Division )
ORCID ID0000-0001-7152-8337KAKEN Researcher No.: 80965244Andrianary Bruce Haja ( University of Antananarivo )
Rakotonindrina Hobimiarantsoa ( University of Antananarivo )
Ramifehiarivo Nandrianina ( University of Antananarivo )
- ほか
- Publication, etc.
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Andrianary et al. (2024) Field Crops Research 318: 109601.https://doi.org/10.1016/j.fcr.2024.109601
- Japanese PDF
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2024_B05_ja.pdf568.39 KB
- English PDF
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2024_B05_en.pdf252.4 KB
＊ Affiliation at the time of implementation of the study.