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Abstract

Improved varieties of legumes adapted to nutrient deficiency have the potential to improve food security for the poorest farmers. Tolerant varieties could be an inexpensive and biologically smart technology that improves soils while minimizing fertilizer costs. Yet other technologies that improve productivity and appear to be biologically sound have been rejected by farmers. To translate benefits to smallholder farmers, research on low-nutrient tolerant genes and crop improvement must keep farmer preferences and belief systems in the forefront. We review farmer participatory research on legume-intensification and soil fertility management options for smallholder farmers in Africa, including recent results from our work in Malawi and Kenya. We suggest that indeterminate, longduration legumes are the best bet for producing high quality residues, compared to short-duration and determinate genotypes. This may be due to a long period of time to biologically fix nitrogen, acquire nutrients, photosynthesize and grain fill. Also, the indeterminate nature of long-duration varieties facilitates recovery from intermittent stresses such as drought or pest pressure. However, indeterminate growth habit is also associated with late maturity, moderate yield potential and high labour demand. These traits are not necessarily compatible with smallholder criteria for acceptable varieties. Malawi women farmers, for example, prioritized early maturity and low-labour requirement, as well as yield potential. To address complex farmer requirements, we suggest the purposeful combination of species with different growth habits; e.g. deep-rooted indeterminate long-duration pigeonpea interplanted with short-duration soyabean and groudnut varieties. On-farm trials in Malawi indicate that calorie production can be increased by 30% through pigeonpea-intensified systems. Farmers consistently indicate strong interest in these systems. In Kenya, a 55% yield increase was observed for a doubled-up pigeonpea system (a double row of pigeonpea intercropped with three maize rows) compared to traditional, low density intercrops. However, the need for improved pigeonpea varieties with high intercrop suitability, including reduced early branching, was highlighted by a farmer preference study in the same area. These examples illustrate the potential for participatory research methodologies to drive biophysical research in farmer-acceptable directions.

A Typology and Preferences for Pigeon Pea in Smallholder Mixed Farming Systems in Uganda

“…Similar results were reported in Kenya and the Democratic Republic of Congo (DRC), where farmers preferred pigeon pea due to its nitrogen fixing capability and thus high soil fertility improvement potential [57]. Likewise, Snapp and Silim [58] illustrated that smallholders in Kenya and Malawi prefer pigeon pea varieties that were high-yielding and had a good inter-cropping ability. Given the semi-arid nature of northern Uganda and the increasing effects of climate change [29], 44%, smallholders rank pigeon pea as one of the crops that can survive during the hot seasons compared to other legumes and cereals.…”

Smallholder Farms and the Potential for Sustainable Intensification

“…This is an uncommon cropping system practice, in contrast to the combination of legume-cereal that is biologically complementary and a widespread practice on smallholder farms in Malawi and elsewhere (Shaxson and Tauer, 1992). Complementarity of legume crops can be achieved through the deliberate combination of early and late growth habits, with shallow versus deep rooting systems, to reduce competition for resources (Snapp and Silim, 2002). However, this doesn’t seem to be achieved by the farmer mixtures reported, which involved legumes with similar growth characteristics such as soybean and groundnut.…”

“…Action research was initiated in the beginning of the growing season (November 2012), to introduce modern varieties of legumes and doubled-up legume technologies, including mixtures of pigeonpea and soybean as well as improved varieties of groundnut and cowpea. This key SI farming technique involves growing a two-legume intercrop in the first season, followed by intercropped pigeonpea and maize or sole maize in the second season (Snapp and Silim, 2002). Residue management of the doubled-up legume system is crucial to obtaining benefits for soil fertility as well as enhanced harvests (two crops) per land area (Bezner Kerr et al, 2007).…”

Perennial Grains for Africa: Possibility or Pipedream?

“…Crop damage by livestock in the dry season is a significant barrier to growing a long-duration pigeon pea or a ratoon crop in many locations (Snapp and Silim, 2002; Waldman et al , 2017). This is less of an issue in the Southern Region of Malawi, perhaps related to the small landholdings and the existence of markets for pigeon pea, where community norms are in place that control livestock so as to protect perennial, ratooned pigeon pea (Orr et al , 2015; Ortega et al , 2016).…”