**2. The state of irrigation schemes in northern Nigeria**

This section presents the review on the state of irrigation schemes in northern Nigeria and sustainability pillars were used to guide this review. The aim was to get more insight into the global irrigation scheme operations and maintenance practices with the main focus on northern Nigeria. This review yielded a schematic overview of irrigation scheme management using sustainability pillars. This is to evaluate the present state of functionality and the level of impact on the lives of people. **Figure 1** shows the map of Nigeria showing the northern part, which constituted three regions (North West, North East and North Central), and southern part, which constituted three regions (South West, South East and South South). The irrigation scheme management sustainability-based review was conducted and restricted to the northern part of the country. The history of irrigation practices in the northern Nigeria begun since when it was realized that the region is characterized with low rainfall and high rate of evaporation which make it either arid or semi-arid regions in addition to abandon arable lands. These made the previous governments of the regions to construct several water storage infrastructures (dams and canals) for irrigation practices. These resulted to several major irrigation schemes available in northern Nigeria most of which are intended to stimulate and facilitate the sustainable food production in the country.

**Figure 1.** *Map of Nigeria showing 3 northern and southern regions.*

#### **2.1 Economic aspect of irrigation schemes sustainability**

The economic productivity of several human endeavors depends largely on access to water resources [16]. Although about 24% of the global land area suffering from severe water scarcity [17] and 35% of the global population living in areas affected by water shortages [18], the economic development often occurs at the cost of overexploitation of water resources [19]. Agriculture is a major performer in the human appropriation of the limited water resources as about 70% of the global freshwater is consumed by this sector. After abandonment for about four decades due to abundant petroleum resources, the agricultural sector in Nigeria is gradually occupying a dominant position in the development of the national and rural economy. The sector provides not only food but also serves as the major source of employment to the teeming population of Nigeria. The agricultural sector provides jobs to about threequarters of the Nigerian working population [20]. Farmers are usually less busy on the farm during the dry season, putting into account the rainy (May to October) and the dry (November to April) seasons of Nigeria. Hence, the provision of irrigation facilities that offer the opportunity for all-year-round farming can serve as an alternative source of employment and an additional gain to the Nigerian economy [21].

Recently, drastic agricultural reforms (closure of land borders and banning of importation of major agricultural food products among others) have been made in Nigeria resulting in a sharp increase in crop production which significantly reduce food importation and jobs were created [22, 23]. Agriculture is one of the main economic sectors in Nigeria employing about 60% of the population of the country [23]. This scenario is in line with other developing countries that agriculture provides the leading source of employment. Thus, increasing agricultural productivity is critical to economic growth, development, and the nation's Gross Domestic Products (GDP). One important way to increase agricultural productivity is through the introduction of improved agricultural technologies and management systems.

In Nigeria, post-project evaluations of the majority of the irrigation schemes revealed that their economic performances are low compared to pre-project predictions [14, 15]. Such undesirable outcomes are a result of the fact that social and environmental concerns of these schemes were not incorporated in the analysis. The participation issue presents the usefulness of water users' involvement in the maintenance and sustainability of the irrigation schemes which further improve economic benefit [24]. One of the possible causes of the decline in food production is an inefficient allocation of resources in the agricultural production potentials [25]. For example, Land, labour, capital and water resources are inefficiently allocated thereby leading to a decrease in their productivity. To further improve the economic status of the rural dwellers as well as to attain food security and national growth, irrigation schemes need to be revitalized to increase food and cash crops production [26].

The economic welfare of a country and its ecosystem health is directly linked to water stress and the rate of water depletion [24]. Evidently, the Kano River Irrigation Project (KRIP) has played an important role in discouraging migration from rural to urban centers and alleviating the employment problems of its immediate community [20]. Similarly, there has been a sharp difference from the dry season farmers' income in Bauchi State when compared with rain-fed farmers for the same kind of farm produce. The dry season (irrigation) farmers get more profit than rain-fed farmers counterparts. This is not unconnected with the high demand for fresh irrigated crops during the dry season [27]. Moreover, a study on the Socio-economic impact of an irrigation project in Taraba State reported similar findings among the farmers

in respect of economic gain. Project on the beneficiary of the Fadama II project in Kaduna State indicates an increase in the net farm income of the beneficiary farmers [28]. Hence, creating a more efficient irrigation water management approach has the potential to substantially increase agricultural production, farmers' incomes, and create employment opportunities.
