Widespread and persistent rural poverty is a longstanding problem in both Asia and Africa, particularly where farmers grow rice without irrigation, areas referred to as “rainfed ecosystems.” Rice is dominant in these areas because it is the only crop that can be grown in the wet season. In Asia, it is the rural population’s staple food (up to 60% of energy intake) and the principal source of employment (50–70% of the labor force). About 30% of the 700 million people in absolute poverty (with income of less than US$1 per day) in all of Asia live in rainfed rice-growing areas in South Asia (SA). In West Africa, more than 45 million people depend on rice farming, most of it rainfed. In East and Southern Africa (ESA), where 2 million hectares are planted to rice, 120 million people live in absolute poverty. Rice yields in rainfed ecosystems—there is a total of 60 million hectares in Asia and 12.9 million hectares in sub-Saharan Africa (SSA)—remain low (0.5–2.5 t/ha) and unstable—unstable due to the abiotic stresses of drought, flooding, poor soils, and cold. Compounding the problem is looming climate change, which will increase the frequency and intensity of abiotic stresses.
The problem: abiotic stresses in rice and resulting factors
In Asia, drought and submergence plague tens of millions of rainfed rice lands each year. In SSA, 80% of the total rice area is rainfed and faces the same constraints as rainfed rice in Asia. Average rice yields are only 1.5 t/ha and total rice production in SSA reached only 12.7 million tons from a harvested area of about 8.5 million hectares in 2004 (Balasubramanian et al 2007). NERICA rice varieties have recently given new hope for increasing yields in Africa but early success has been for upland rice, which covers only about one-third of the total rice area. Expansion of upland rice area, unfortunately, presents much larger environmental and sustainability challenges than rainfed lowland rice.
The overwhelming importance of rice to poor Asians—both rural and urban—is well documented. However, in Africa, rice is the fastest growing food and cash crop, in terms of both production and consumer demand, with 40–45% of the rice consumed being imported. Rice imports in 2008 and 2009 into SSA were about 10 million tons. This is more than a third of internationally traded rice at a cost of about $4 billion, a huge burden to many African countries with limited resources that can support an expansion in area in SSA. Rice has a major advantage over other crops, which is of particular relevance for agricultural development in SSA. Unlike maize and cassava that quickly deplete poor soils when grown with little or no fertilizer by subsistence farmers, a continuously flooded lowland rice system is among the most sustainable and productive cropping systems in the world, even with no fertilizer input. Nitrogen-fixing bacteria and algae flourish under flooded conditions and changes in soil chemistry free phosphorus for uptake by rice plants. Even when lowland rice is grown without fertilizer, it typically yields two or three times more than upland crops grown on the same soil. However, these crops will face the threat of drought, adverse soils, and uncontrolled flooding and submergence.es. Relying on the world market to supply rice is becoming a very risky, expensive, and unsustainable strategy. Rice prices have increased sharply over the last three years and global stocks are declining. The 2008 high rice prices caused riots in major African capitals. To avoid severe food insecurity, civil instability, and an economic downturn, there is an urgent need to increase rice production, processing, and marketing in SSA. This is especially the case in West Africa, where rice is the staple food. There is an abundance of agro-climatically suitable wetlands and water resources.
Crop loss to drought and floods has a human dimension that is not captured by simple monetary losses. As farmers liquidate capital such as livestock, farm implements, and even land simply to survive, they seriously limit their future options for years to come. And, as happens all too frequently, they are forced to take children out of school or are unable to adequately nourish pregnant women and young children. As a result, members of the next generation are condemned to poverty even as their lives are just beginning. Other family members migrate on a seasonal or long-term basis, leaving the elderly and women behind to manage their farms (Paris et al 2005). Poor women, particularly members from poor farming households, contribute more labor inputs than men in areas that suffer from abiotic stresses such as drought, submergence, and sodic soils (Paris et al 2008b). These poorest of the poor will stay that way unless the farm families among them can obtain higher income through higher and more stable rice yields in the rainfed environments where rice productivity is chronically constrained by drought, flooding, poor soils, and temperature extremes.
In addition to limitations in access to technology and information, marketing infrastructure and seed production institutions are poorly developed. Farmers in rainfed areas often have no access to good-quality seed of released varieties. These farmers, both men and women, also lack knowledge and training to produce good-quality seed and they have to use poor-quality seed produced on their own land in the previous season.