Niger is a country with an agro-pastoral vocation. The country's economy is mainly based on agriculture and livestock which occupy more than 90% of the population (Warouma et al., 2013) and agriculture contributes 40% to the GDP (Ndiaye et al., 2013). Rice is the third cereal after millet and sorghum in terms of production and represents only 1.7% of the turnover of the agricultural production sector (Niger Rice Sector Strategy, 2009). For the intensification of irrigated crops, especially rice, efforts undertaken by Niger government and its development partners have made it possible to carry out 58 Hydro Agricultural Plannings for rice cultivation totaling 8 500 ha out of the 24 000 ha of cultivable plots (ONAHA, 2013). National rice production is estimated at 132 030 tones of paddy, of which 70 000 tones are produced on the Hydro Agricultural Plannings in the Niger  River Valley and 62 030 tones excluding Hydro Agricultural Plannings (AGRHYMET, 2006). However, this production only covers one third (1/3) of the annual national needs estimated at 266 710 tones of white rice (Sido, 2010). The workforce provided by human energy is insufficient to meet the challenge in Niger. Hence, there is necessity of mechanization. In sub-Saharan Africa, agricultural mechanization is still at the earliest stage of development (Rijk, 1989). Agricultural energy is supplied by humans (65%), animals (25%) and engines (10%) (Clarke and Bishop, 2002). Mechanization contributes to increase the areas developed, to reduce the hardship of agricultural activities, to improve the quality of production and processed products on the one hand, and to foster industrialization driven by agriculture on the other hand (FAO, 2008). Several studies around the world have demonstrated the role of technology on crop yields. For example, the use of steel plows for heavy soils significantly improved grassland yields in the United States in the 1840s (Gifford, 1993). In the Office zone of Niger (Mali), the use of tiller has made it possible to achieve rice production objectives of 6 t/ha against 3 to 4 t/ha without a tiller (FAO, 2002). The increase in yields induced by mechanization was noted by Saer et al. (2021). Nowadays, many localities in Niger do not even have animal traction. However, animal-drawn mechanization is the logical transition between manual and motorized cultivation (Bichat, 1984). It is very difficult to imagine the development of agriculture without equipment (Abdourahamane et al., 2020). The development of mechanization had begun to take shape with the realization of Hydro-agricultural Plannings and the creation of the national agency for that effect (ONAHA, 2013). No study was carried out on the impact of mechanization on rice production at the level of these Hydro-agricultural Plannings. That is why this study has targeted the mechanization of rice cropping with the main objective to examine the role of mechanization in this sector in Niger.

Study sites location

The present study was carried out in the villages of Saga Goungou, Libore Bani Goungou and Gueri Guinde Zarma, all located in Niamey IV municipality located between 13°24" and 13°35" North latitude and 2°00" and 2°15" East longitude. This area is bounded to the North by the municipality of Hamdalaye, to the south by the NY V municipality, to the East by the municipality of Libore and to the West by the NY II municipality. The annual rainfall varies between 400 to 600 mm and the average annual minimum and maximum temperatures are respectively 13 and 45°C (PDC, 2009). The material used during the field surveys is composed of the followings:

(i) Draft animals from farms;

(ii) Coupling equipment for farms;

 (iii)  A GPS for determining geographic coordinates and field extent;

(iv) Survey sheets intended for farmers for data collection;

(v) A camera for taking pictures;

(vi) Word, Excel and SPSS19 softwares for analysis, data processing and report writing.

It consists of collecting quantitative and qualitative data for the conduct of this study, which was carried out in the following phases: literature review, equipment used, sampling, data collection and processing.

Sampling

The selection of the villages took place in the presence of the Director of Saga Hydro-Agricultural Plannings Perimeter and the Head of the cooperative. The perimeter counts 1 622 farmers spread over 11 villages. Thus, after a draw, three villages were selected to conduct the study, namely Saga Goungou, Libore Bani Goungou and Gueri Guinde Zarma. The sampling of farmers was also carried out in a random fashion. The survey was carried out on 90 farmers with 30 farmers per village.

Conduct of the investigation

It took place from September 25^th to October 10^th, 2019. The first step was to collect data from the farmers trough meetings at the cooperative office, at the perimeter plots during their work and at their homes. The second step concerned the observations made on the farms.

Data processing

Excel, Word and SPSS19 softwares were used for data processing, report writing, production of graphs, tables and statistical tests. The single-way ANOVA test was used to compare means between villages and the single-sample test was used to see if the mean of a variable was different from a specified constant. These analyzes focused on the following aspects:

(i) Characterization of the surveyed farms;

(ii) Identification of mechanical tools;

(iii) Productivity evaluation.

The investigation shows that no woman appears on the list of surveyed farmers.

Methods of acquisition of rice fields

The methods of purchasing rice fields are diversified. Some farmers have more than one type of plot acquisition, hence the grouping of acquisition as follows: Purchase, purchase and inheritance, purchase and contract, inheritance and contract, inheritance and finally contract. Operation contracts only concern those issued by the National Office for Hydro-Agricultural Plannings (ONAHA). Figure 1 shows that  the  contract  is  the  most frequent among the acquisition types and this concerns all three villages while the "Inheritance and contract" grouping is the least frequent.

Agricultural manpower

The agricultural manpower in the three villages are all male. 146 agricultural manpower were registered in Saga Goungou, 135 in Libore Bani Goungou and 133  in  Gueri Guinde Zarma (Figure 2).

Surface area of ??farms surveyed

The total surface areas of the villages of Saga Goungou, Libore Bani Goungou and Gueri Guinde Zarma are respectively 13.75; 14.25 and 12 ha (Figure 3). Although it is in Saga Goungou that the number of agricultural manpower  is  higher,  the  area worked by the farmers of Libore Bani Goungou is higher than that of the other two.

Machines and tools used

It can be seen that despite the use of motorized and animal-drawn tools, manual tools continue to be used by the farmers of these three villages. Regarding motorized tools, the highest number was observed at the level of tillers. It is 37 with an average of 1.23 ± 2.38 for the farmers of Libore Bani Goungou against 35 with an average of 1.16 ± 2.25 for Gueri Guinde Zarma and 34 with an average of 1.13 ± 2.19 for Saga Goungou. No significant difference was found between the three villages (ddl = 2; F= 0.15; p = 0.985). However, the tests on the samples show a significant difference in the three villages (t= 2.831; ddl = 29; p = 0.008). For animal-drawn plows, the highest number was observed in Saga Goungou where 45 were counted with an average of 1.2 ± 2.9 against 41 with an average of 1.36 ± 4.94 in Libore Bani Goungou and 40 with an average of 1.33 ± 4.82 at Gueri Guinde Zarma. The comparison of the means between the villages shows no significant difference (ddl = 2; F= 0.13; p = 0.987). Similarly, the test on the sample from each village does not show any significant difference (t = 1.516; ddl = 29, p = 0.140). For manual tools, the highest number of hoes was found in Gueri Guinde Zarma (53) with an average of 1.76 ± 6.39 against 48 with an average of 1.6 ± 3.09 in Saga Goungou, and 41 with an average of 1.36 ± 4.94 at Libore Bani Goungou (Table 1). No significant difference was obtained between the means of the three villages (ddl =  2;  F =  0.13;  p  =  0.987).  As  for  the test  on  the sample, it only showed a significant difference in Sqga Gorou (t = 2.835; ddl = 29, p = 0.008). In the farms of these 90 respondents, only two tractors were identified.

Figure 4 shows the type of acquisition of motorized and animal-drawn tools. For motorized tools, the type of acquisition by rent is more dominant for the three villages. As for animal-drawn tools, the most dominant type of acquisition is by purchase. For hand tools, their acquisition types are 100% purchase for the three villages.

Productivity and labor

Work productivity and labor for the same energy source remain the same in the three villages (Table 2). On the other hand, the labor taking into account the different energy sources does not remain the same. Thus, the productivity of motorized, animal-drawn and manual plowing works are respectively 8 h/ha, 1 days/ha (12 h/ha) and 10 persons /days /ha, while the cost of labor per hectare is 32 000 FCFA for motorized plowing, 28 000 FCFA for animal-drawn plowing and 20 000 FCFA for manual plowing.

This study revealed the importance of mechanization in rice cultivation in the Niger River region, particularly in the villages of Saga Goungou, Libore Bani Goungou and Gueri Guinde Zarma. Through this research, it was notified that only the government agency (ONAHA) can contract the plot to farmers in this zone but in practice all types of acquisition of plots have been identified with the inheritance and contract being the most common. For the acquisition of animal drawn and motorized tools, purchase and rent are the most common. Animal traction is the most used source of energy during the first plowing, but farmers still continue to use hand tools because harvesting (cutting, threshing, winnowing) and transplanting are carried out exclusively manually. The intermediate engine is used by all farmers during the second plowing (leveling). In intermediate motorization, the plowing of a hectare is carried out in 8 h of time, in animal traction (a pair of oxen) it takes one day and manually it takes 10 persons to plow a hectare in one day. Mechanization increases the areas developed, reduces the hardship of agricultural activities and improves the quality of work by reducing labor and working time. However, this study only focused on the Niger River region. These results clearly show that mechanization improves agricultural production in this area.

The authors have not declared any conflict of interests.