Buffering soil water supply to crops by hydraulic equilibration in conservation agriculture with deep-rooted trees: application of a process-based tree-soil-crop simulation model to parkland agroforestry Systems in Burkina Faso

Abstract

Farmers deal with risks such as weather, pests, diseases, costs of inputs, market prices of products, (family) labour availability, policies regulating land use and, in some contexts, open interpersonal conflict. Perennial components of agricultural systems, especially trees, provide buffer and filter functions that modify, and generally reduce, the farmers' sensitivity to such external variables. Maintaining a diversity of activities is a time-tested approach to reducing risks (van Noordwijk et al. 1994). The inclusion of trees that provide annual harvests of fruits or longterm high-value timber can reduce risk, even if the trade-off in resource capture is essentially neutral (Santos-Martin and van Noordwijk 2011). Trees shelter farmers from climate variability and assist in adaptation to longer-term trends (van Noordwijk et al. 2011a)