Assessing rice production sustainability performance indicators and their gaps in twelve sub-Saharan African countries

Abstract

The benchmarking and monitoring of rice production performance indicators are essential for improving rice production self-sufficiency, increasing profitability, reducing labor requirements, optimizing fertilizer inputs, engaging youths in rice production, and increasing the overall sustainability of smallholder rice production systems in countries in sub-Saharan Africa (SSA). In this paper, we quantified five sustainability performance indicators (grain yield, net profit, labor productivity, and nitrogen (N) and phosphorus (P) use efficiencies) to benchmark rice production systems in SSA. Data were collected between 2013-2014 from 2907 farmers from two rice production systems (irrigated and rainfed lowlands) across five agroecological zones (arid, semiarid, humid, subhumid and highlands) in 12 countries (Benin, Cameroon, Cote d'Ivoire, Ghana, Madagascar, Mali, Niger, Nigeria, Senegal, Sierra Leone, Tanzania and Togo). The exploitable gap for each indicator (the difference between the mean of 10 % highest-yielding farms and the mean-yielding farms) was calculated across the countries, the two production systems and agroecological zones. The mean yield varied widely between 2.5 to 5.6 t ha^-1 and 0.6 to 2.3 t ha^-1 in irrigated and rainfed lowlands, respectively, with an average yield of 4.1 and 1.4 t ha^-1, respectively. Across the country-production system combinations, there were yield gaps of 29-69 %, profit gaps of 10-89 %, and labor productivity gaps reaching 71 %. Yield, profit, and labor productivity were positively correlated. They were also positively correlated with N and P fertilizer application rate, but not with N and P use efficiencies. Only between 34-44 % of farmers had desirable ranges in N- or P-use efficiencies in the two production systems. All sites for rainfed lowlands were characterized by low-yield and large gaps in yield, profit, and labor productivity, whereas irrigated lowlands in some countries (Madagascar, Mali, and Togo) have similar characteristics as rainfed ones. We conclude that there is an urgent need to disseminate precision nutrient management practices for optimizing nutrient use efficiency and enhancing rice performance indicators especially in rainfed lowlands as well as low-yielding irrigated lowlands. Furthermore, we propose recommendations for specific categories (i.e. farmer, rice production system, agroecological zone and country) to close performance indicator gaps and to allow the production at scale to achieve rice self-sufficiency in SSA.

Keywords: Irrigated lowland; Net profit; Nitrogen use efficiency; Phosphorus use efficiency; Rainfed lowland; Yield gap.

Fig. 1

Surveyed areas in sub-Saharan Africa.

Fig. 2

Box-whisker plots of rice yield in irrigated lowland (IL) and in rainfed lowland (RL) production systems: the mean farmer population (0), the bottom 10 % (1), middle 80 % (2), and top 10 % (3) of farmers in 12 countries in SSA. Six countries (Cote d’Ivoire, Ghana, Mali, Nigeria, Togo and Madagascar) had both IL and RF, two countries (Niger and Senegal) had only the IL and four countries (Benin, Cameroon, Sierra Leone, and Tanzania) had only the RL represented in the survey. For the detail survey site name in the respective country, see Table 1, Table 2.

Fig. 3

Box-whisker plots of net profits in rainfed lowland (RL) and irrigated lowland (IL) production systems: the mean farmer population (0), the bottom 10 % (1), middle 80 % (2), and top 10 % (3) of farmers in 12 countries in SSA.

Fig. 4

Box-whisker plots of labor productivity in rainfed lowland (RL) and irrigated lowland (IL) production systems: the mean farmer population (0), the bottom 10 % (1), middle 80 % (2), and top 10 % (3) of farmers in 12 countries in SSA.

Fig. 5

Box-whisker plots of nitrogen (upper two rows) and phosphorus (lower two rows) use under rainfed lowland (RL) and irrigated lowland (IL) production systems in 6 countries in SSA.

Fig. 6

Trade-offs among different indicators and inputs for farmers in three yield gap categories applying under irrigated and rainfed lowlands in 12 countries in SSA. Indicators: yield = grain yield, profit = net profit, LP = labor productivity, NUE = nitrogen use efficiency, and PUE = phosphorus use efficiency. Input values: seed = seeding rate (kg ha⁻¹), TCP = total cost of production ($ ha⁻¹), labor = no. of labor days ha⁻¹, Ele. N = elemental N kg ha⁻¹, and Ele. P = elemental P kg ha⁻¹. The values are the averages for the bottom 10 %, top 10 % and middle 80 %. NUE and PUE values are compared only for Cote d’Ivoire, Mali, Togo, Niger, Senegal and Benin. Cameroon, Madagascar, Sierra Leone, and Tanzania were excluded from this figure because they had very high or low NUE and PUE values.

Fig. 7

Scatter plot of the correlation between performance indicators and production inputs in the irrigated lowland production systems.

Fig. 8

Scatter plot of the correlation between performance indicators and production inputs in the rainfed lowland production systems.