The New Harvest is a book that falls somewhere between a manifesto and a manual. It calls for a concerted effort to apply science, technology and investment to the goal of raising African agricultural productivity. At the same time, Calestous Juma provides many examples of the kinds of efforts already underway in Africa and around the world that he thinks could be the key to Africa's agricultural transformation.

This book is a product of the Agricultural Innovation in Africa project, funded by the Bill and Melinda Gates Foundation and centered at Harvard's Kennedy School. Though authored by Juma, the book acknowledges the contributions of 19 additional contributing authors from academia and development organizations from around the world. The book's eight chapters cover the potential for growth based on a transformation of agriculture, advances in science and technology, agricultural innovation systems, infrastructure, human capacity, entrepreneurship, and the importance of governing the transformation through regional economic communities. Each topic is explored largely through examples of successful agricultural or rural development efforts from Africa, Asia, and Latin America.

The New Harvest is addressed to high-level decision makers in Africa who are called upon to integrate research and development efforts, technology implementation, education, and various public policies (e.g., regulation, investment, credit) to promote the adoption of new technologies in agriculture. The intended audience may explain the book's optimistic, and sometimes simplistic, formulation of its recommendations. Juma claims that three opportunities converge to make Africa's agricultural transformation possible: new advances in science and technology, new efforts to create regional integration, and a new generation of African leaders (p. xiv). The strategy he promotes is one of increasing agricultural productivity aimed at food production for Africa (rather than exports) distributed through regionally integrated markets (p. 10).

The central contribution this book makes is to remind us that technologies already exist which could transform the productivity of African agriculture. What has been lacking up to this point is the political commitment to devote the resources necessary to realize such a transformation. The thrust of the book is clearly indicated at the outset (pp. 2–4) where Juma applauds the success Malawi enjoyed in expanding maize output once President Bingu wa Mutharika committed significant government resources to the problem of low output. The New Harvest is refreshingly focused on African leaders' responsibility for development. The book does not discuss the role of foreign aid nor assume that it is vital to Africa's potential. The strategies it promotes (e.g., subsidies) do not conform to the strictures of neoliberalism, though the private sector is intimately involved in the transformation Juma sees. The book also serves as a collection of ideas that have proved successful, if not in Africa, then elsewhere in circumstances more or less akin to those in Africa. Students of development as well as practitioners will find the quick overview of ideas useful with footnotes that guide the reader to published source material.

The New Harvest is rooted in a technological optimism in which existing technologies are the keys to transformation. There is little attention paid to the details and challenges of successfully managing public policies. The book repeatedly points to the important role the regional economic communities must play, but the challenges of leadership, will, and wisdom, and policy management and implementation, are simply ignored. Great faith is put in the new generation of African leaders to see through this agricultural transformation (p. xiv). Good leadership that puts public interests ahead of all others, is wise in its setting of priorities, and succeeds in cooperating with regional partner states is considered a given. Accountability mechanisms are not among the technologies sampled. Chapter 7, which discusses governing innovation through regional organizations, assumes that the organizations' member governments will agree on the best joint strategies, though the history of regional integration suggests that this is seldom straightforward. Furthermore, the process of creating regional management structures is treated as a technical one (e.g., establishing regional universities, harmonizing Sanitary and Phytosanitary Standards): there are no politics in this treatment.

Though many citations are made to scholarly journals, the evidence in the book often appears to be anecdotal, and facts are sometimes recited without references (e.g., pp. 32–33, 85, 87–88, 91–92). The discussion of each idea is typically short, often only a page or two, so that the narrative does not get bogged down in details. At the same time, however, the paucity of detail leaves the reader wondering what devilish problems had to be solved for these technologies to succeed. In a few cases (e.g., China's experience reforming its innovation system—pp. 77–81), Juma draws cautionary lessons from the experiences to which he refers, but for the most part he ignores studies which challenge the impact of these success stories. For example, in his discussion of the fresh vegetable export experience in Kenya (pp. 156–57) no reference is made to the considerable literature which is critical of these value chains.

The transferability to Africa of success stories from outside Africa is assumed without any consideration of the contexts in which they succeeded. For example, Juma cites a Franco-British consortium partnership with South Korea to develop and produce high-speed trains in Korea as an example of technology transfer which Africa should emulate (pp. 104–09). But is this example relevant to Africa's situation? Is it relevant to the agricultural innovation Juma calls for? While Juma acknowledges that every idea needs to be adapted to local circumstances, a lot of assumptions are obscured by such a sweeping approach to transferability.

Finally there are some dimensions missing. Gender is rarely in focus (an exception is his discussion of the need to educate women about agricultural technologies—pp. 116–20). Social technologies (e.g., microfinance; formation of smallholder agribusinesses/cooperatives) are mentioned, but are treated as ancillary to the physical technologies that are the real driving forces of transformation (e.g., pp. 162–63). And there is no direct discussion or examples of the transformation of livestock (as opposed to crop) production.

Practitioners of development are likely to find the book a handy reference. African policy makers may see a roadmap forward for regional planning and integration. But academic audiences are likely to want a more careful consideration of the assumptions on which the potential successes of the strategies are based. And critics will find the book's technological optimism unrealistic and naïve. However, Juma has, I suspect, deliberately and consistently avoided such debates to emphasize the call on Africa's leadership to move the continent forward.