For these reasons, the amount of new land available for expanding rice production is already limited in some countries and, with time, land frontiers in Africa will eventually close. It is perhaps telling that, while the average amount of arable and permanent cropland per capita of agricultural population is significantly larger than in South Asia today, the amount is not so different from the late 1960s, when Asia’s Green Revolution was getting underway (Figure 6). Moreover, events in global markets may hasten this process, since there is evidence that gains from low-land innovations of the type that fueled Asia’s Green Revolution are slowing. For example, Hossain (2007) finds that, world-wide, annual yield gains for irrigated and partially irrigated rice from 1990 to 2005 slowed to 0.7 and 1.7 percent, while the growth in rainfed yields was largely unchanged. With new land suitable for rice limited elsewhere, the deceleration of yield growth among the world’s largest rice producers and the growing demand for rice in and out of Africa will create new incentives for farmers in Africa to adopt the land-conserving farming practices common in Asia.

# **A New Rice for Africa**

The previous sections highlighted the current importance of lowland rice and the slow pace of improvement in rainfed yields worldwide. Overall, yield improvements can come about by improving the way current crop technologies are applied and through the innovations in the form of new varieties. In the next section, we explore this first avenue for improving yields, looking especially at crop husbandry and water management practices commonly used in Asia that can be adapted for use in Africa. But in this section we turn our attention to a new family of rice varieties, initially developed for rain-fed conditions.

This family of varieties is based on the successful crossing of an African (Oryza glaberrima) and Asian (Oryza Sativa) rice and the term, NERICA (New Rice for Africa) applies to the rice varieties that come out this interspecific crossing of the two distinct rice species.<sup>16</sup> Field tests suggest the new varieties hold great promise with higher yield potential under a variety of soil and weather conditions, more protein, a shorter growing period, and a greater resistance to African pests and diseases.

NERICA varieties were developed at the main M’bé research center of the Africa Rice Center (AfricaRice), through conventional crossbreeding. AfricaRice estimates that the initial research, which focused on upland rice, generated more than 3,000 interspecific siblings, encompassing a wide variety of attributes. By the close of 2005, 18 upland varieties (NERICA1-NERICA18) has been selected through Participatory Varietal Selection (PVS) and on farm trials by African NARS for release in their countries. On-farm tests report paddy yields in excess of 1 ton per hectare (Table 4) without fertilizer in rainfed areas and up to 5.7 tons per hectare when fertilizers are applied (Table 5). AfricaRice has also examined ratooning yields – that is, a secondary production obtained by leaving the lower part of the rice plant during harvesting. Based on field studies from Dévé, a savannah zone of Benin, Sanni et al., (2009) report that ratooning yields ranged from 39

> 16 This section draws on an informative NERICA compendium edited by Somado, Guei and Keya (2008).

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