Possibility or pipedream?
Journal: Experimental Agriculture
Authors: Sieglinde Snapp, Paul Rogé, Patrick Okori, Regis Chikowo, Brad Peter, and Joseph Messina
Date accepted: 2018-09-01
Perennial grain crops have been proposed as a transformative approach to agriculture. Replacing annual staple crops with perennialized growth types of the same crops could provide direct benefits to farmers, including labor efficiency, seed saving, weather resilience, and livestock fodder or fuelwood production, in combination with food production. There are also environmental benefits associated with perennial crops as their relatively long growth habit is essential to conservation of soil, nutrients and water quality, and yields can be high. Yet to date, agronomy has focused almost exclusively on annual crops. Sustainable intensification technologies under development on smallholder farms in Africa is a case in point: annuals and double cropping of annuals is overwhelmingly prioritized. In this paper we review the literature to explore this focus on highly annualized grains as the only sustainable intensification cropping system option, and why agronomists generally perceive perennial grains as a pipedream. The case studies of pigeon pea and sorghum are considered, as an analog for perennial grain crops in Africa. Through review of the literature we find that a substantial number of farmers persist in ‘perennializing’ pigeon pea systems through ratoon management, and sorghum ratoons are widely practiced in Ethiopia. Agronomists and extension recommendations do not acknowledge the existence of ratooning as a management option, nor do crop scientists select for longer-duration growth habit or perennial traits in pigeon pea or in sorghum. Research priorities are the exact opposite. A highly annualized, short-statured and extra-early maturity growth habit is presented as the ideal for an improved pigeon pea type. Similarly, in sorghum, short-statured types with a high harvest index have often been an almost exclusive focus, until recently. Several lines of evidence indicate that these two examples are consistent with many agronomy efforts in Africa, where crop yield is the primary criteria for technology selection. This leads to a preference for ultra-annual growth types that are highly responsive to inputs. Such agronomy selection criteria appear to have excluded attention being given to ratooning grain crops or developing multipurpose, perennial life forms that could produce other services in addition to grain. Agronomists are encouraged to consider a wider range of indicators of performance for a sustainable approach to agriculture, one that includes managing for diversity in crop growth patterns.
Keywords: annual, perennial, multi-purpose, ratoon, ecosystem services, commodity agriculture