Homegardens: a highly productive form of agriculture that can benefit biodiversity

BY C4 EcoSolutions ON 29 August 2015

Homegardening is a form of agriculture that has been practised for centuries in tropical and temperate climates. Each homegarden is unique, but in general they are small‑scale (~30 m2) and maintained by individual households. These gardens are places of innovation where gardeners undertake perpetual experiments, trying and testing new plant species and varieties, as well management strategies. The selection of plant species and methods of cultivation are variable and each homegardener uses his or her own particular knowledge-base and skills of ingenuity. Primarily, homegardens are a source of food, livelihood and culturally important plant species. Unlike conventional agricultural practices, homegardens are closely linked to natural ecosystems in that many indigenous local plant species are used by the gardeners. They are often also home to a wide variety of indigenous fauna. Indeed, in some cases, homegardens have been shown to have greater biodiversity than undisturbed adjacent ecosystems[1]. This is of relevance to the "sharing or sparing" debate between ecologists who see altered ecosystems as having relatively little biodiversity value and ecologists who view agro-ecological landscapes as beneficial for biodiversity conservation[2]. C4 takes the view that expansion of homegardens in already degraded land is has the potential to simultaneously increase food security, livelihood resilience, biodiversity richness and ecosystem functioning. Particularly for local communities that are vulnerable to the negative effects of climate change[3], homegardens present a unique tool for increasing their adaptive capacity. In the paragraphs below, we discuss the role of homegardening in rural households, as well as within a new UNEP Adaptation Fund project – for which C4 EcoSolutions acts as Chief Technical Advisor – that promotes homegardens in Cambodia. We also suggest how governments, international donors and researchers can support the development and proliferation of homegardens.

Figure 1. Traditional rice agriculture (a) and multi-layered homegardens with trees, shrubs and crops (b) in Cambodia.

One of the primary social benefits of homegardening is its contribution to household food security. Plant and animal products sourced from these gardens usually complement staple crops, and thereby help families save money that would usually be spent on food. Research has also shown that the provision of vitamin-rich fruit and vegetables, as well as medicinal plants from homegardens, greatly improve household health. An additional benefit is the establishment of new local livelihoods through cottage industries[4] selling surplus homegarden products such as cassava, cashews and bananas. In addition to their many social, economic and biodiversity benefits, homegardens provide a wide array of ecological services, such as maintaining soil fertility and soil structure, minimising soil moisture loss, providing shade and increasing the pollination of crops[5]. The considerable density of plants within homegardens also provides habitat for wildlife species such as birds, small mammals, reptiles, and insects.

Figure 2. A multi-species homegarden with cash crops, such as cassava and banana.

Homegardens present a sustainable approach to increasing food security, providing socio-economic benefits, increasing resilience to climate change and enhancing ecosystem functioning. Although these gardens are still grown in many tropical regions, local knowledge and techniques on how to maximise benefits from homegardening are being lost from many places as a result of the commercialisation of agriculture and migration away from rural areas. Without support from governments, the private sector and the international donor community, the culture and extent of homegardening is likely to decline further.

Figure 3. a multi-layered homegarden from Lamjung District, Nepal. A coffee bush is in the bottom left, and a banana tree in the top left of the photograph.

The development of projects focussing on home gardens is of critical importance for testing the hypothesis that synergies can be created between agriculture and biodiversity under climate change conditions. One such project is "Enhancing Climate Change Resilience of Rural Communities Living in Protected Areas of Cambodia" funded by the Adaptation Fund, which is supporting the upscaling of homegardening in conservation areas across Cambodia. The long-term research funded by this project will be quantifying the social, economic and ecological benefits of homegardens thereby providing an evidence-base for future initiatives. Watch this space for news on how this evidence-base is growing.

Figure 4. A biodiversity-rich, multi-layered homegarden in Sri Lanka.

[1] Bhagwat S.A, Willis, K.J, Birks, J.B. & Whittaker, R.J. 2008. Agroforestry: a refuge for tropical biodiversity. Trends in Ecology and Evolution 23, 261-267.

[2] Grau, R. Kuemmerle, T., and Macchi, L. 2013. Beyond 'land sparing versus land sharing': environmental heterogeneity, globalization and the balance between agricultural production and nature conservation. Current Opinion in Environmental Sustainability 5: 477–483.

[3] including droughts, floods and soil erosion

[4] This refers to small-scale industries undertaken at home by family members.

[5] Kumar, M & Takeuchi, K. 2009. Agroforestry in the Western Ghats of peninsular India and the satoyama landscapes of Japan: a comparison of two sustainable land use systems. Sustainability Science 4, 215-232.