The common bean (Phaseolus vulgaris) plays a critical role in the human nutrition of millions of people in southern Africa. While maize as a staple food provides most of the energy requirement, beans containing 22% protein complement maize and other starchy staples to form the basic diet in the SADC region. The common bean is also an important source of carbohydrate and, as such, the bean is the second most important food crop over much of the area. In the widespread maize-based systems of mid-altitude areas of southern Africa, beans contribute up to 30% of dietary energy. Dry beans are particularly rich sources of iron and zinc, and provide vitamins when consumed in such forms as leaves (fresh or preserved) as a side dish or fresh green pods. Thus, beans are an important source of food at the household level for groups vulnerable to malnutrition, including children, pregnant mothers and the poor. Malawi, South Africa and Zambia are net importers of bean from other SADC countries. However, increasing bean productivity can only be realistic when the farming systems include use of improved bean varieties, recommended pest and disease management practices as well as good soil-fertility management practices.
Crop production in southern Africa is constrained by numerous factors, including low soil fertility, restricted access to fertilizers, limited use of high yielding varieties, losses due to field and storage pests, undeveloped markets for agricultural produce and weak extension services. As a result, many rural households in the region are food insecure and suffer from nutritional deficiencies. This situation is very prevalent in Malawi and Mozambique, despite the great potential that both countries have for high agricultural productivity. In order to contribute towards alleviating the problem of low productivity and poor nutrition, this project proposes to diversify agricultural production by introducing and testing new varieties of high yielding low-altitude climbing beans together with proven agroforestry technologies that improve soil fertility.
Maximizing climbing bean yield potential requires climbing beans to be supported by stakes or grown in association with other crops on which they climb. The scarcity of suitable materials for staking is a major impediment to adoption of climbing beans. Agroforestry species such as Calliandra, Gliricidia, Leucaena, Tephrosia and Sesbania can improve soil fertility through nitrogen fixation, while at the same time providing staking material for climbing bean production. This project will leverage the short-term impacts of climbing beans as an incentive for farmers to pursue the longer-term benefits derived from planting multi-purpose trees on soil fertility and improved natural resource management.