North American Agroforestry. Группа авторов

Agroforestry as a Science

      In spite of an increasing awareness of Native American traditional agroforestry practices over the past few decades, in the United States and Canada agroforestry has mainly been viewed as a new science and set of practices tailored to address numerous sustainability issues associated with production agriculture (Matson et al., 1997; Nair, 2007; Jose et al., 2018; USDA, 2019; Jose et al., 2022). Following an era of “efficient production” through the 1970’s, U.S. and Canadian agriculture is slowly transitioning to an era of sustainable production and regenerative agriculture. Development of a sustainable, regenerative agriculture is stimulated by critical issues including long‐term economic decline in rural America, need for crop diversification, and concern about soil erosion, environmental pollution, habitat loss, and climate change. These issues have been accentuated by repeated periods of massive flooding in the greater Mississippi River watershed (e.g., 1993, 2019) raising national awareness of problems stemming from increasingly large‐scale monoculture production farming, especially excessive runoff and flooding, non‐point source water pollution, and loss of critical wildlife habitat (Pimentel et al., 1995; Jordan et al., 2007; Porter et al., 2015; Lerch et al., 2017). Sustainable agricultural practices (e.g., use of cover crops, no till), organic agriculture, regenerative agriculture, are now recognized as viable additions to mainstream production agriculture (Liebman and Schulte, 2015; Geertsema et al., 2016; LaCanne and Lundgren, 2018; OTA, 2018).

While conservation programs were de‐emphasized in the 1970’s and early 1980’s, the sustainable, regenerative agriculture, carbon farming movement has created a more receptive climate for agroforestry development (Liebman and Schulte, 2015; LaCanne and Lundgren, 2018; Feliciano et al., 2018). Agroforestry is directly relevant to sustainable and regenerative land use. The context is that agroforestry concepts and practices need to be incorporated into agricultural production systems to utilize productive niches, diversify products and income, and restore and/or enhance certain ecological services that are vital to achieve sustainable land use (Jordan et al., 2007; Udawatta et al., 2017; Jose et al., 2018). Thus, agroforestry in the United States and Canada is not recognized as an end in itself, but rather an important ancillary discipline contributing to sustainable and regenerative agriculture and sustainable forestry.

      It must be recognized that the present supporting infrastructure, including agricultural research, developed during the “efficient production era”, remains strongly oriented toward commodity production (Sooby, 2003; IPES‐Food, 2016). Moreover, in the United States and Canada, agriculture and forestry land uses are traditionally segregated on the land and in our institutions. Thus, many of the agroforestry concepts (i.e., integrating trees with crops and/or livestock) run counter to traditional thinking and existing infrastructure. To overcome these barriers, it is very important that agroforestry concepts and practices be relevant, pragmatic, and market‐driven to foster interdisciplinary cooperation within our institutions, cooperation among businesses across the market value chain, and adoption on the land (Geertsema et al., 2016; LaCanne and Lundgren, 2018).

In summary, agroforestry in the U.S. and Canada is driven by sustainable development and growth in the “green” marketplace, which in turn will positively affect rural decline and the environmental impacts of agriculture. Agroforestry seeks to help bridge the gap between production agriculture and natural resource management. The development and definition of agroforestry reflects the commodity focus of agriculture, yet it is simultaneously and equally focused on conservation. Global awareness of tropical agroforestry has positively affected the development of agroforestry in the U.S. and Canada, and many of the current practices are adapted from the tropics. However, with foci and priorities differing from those in the tropics (Fig. 2–1), agroforestry over most of North America has evolved its own distinctive definition and nomenclature (Table 2–1). In the United States and Canada, agroforestry is in an active phase of development and, since 2010, has emerged over the past decade as both a science and a defined set of practices, shaped and tailored to address urgent land use sustainability issues. Agroforestry completed the definition phase by the turn of the 21st century and is currently in a period of rapid scientific development (Nair, 2007; Feliciano et al., 2018: Jose et al., 2018; Garrett et al., 2022), outreach (Shelton et al., 2005; Gold et al., 2004; USDA, 2015; Elevitch et al., 2018) and farm‐level application (Faulkner et al., 2014; Rios‐Diaz et al., 2018; Van Noordwijk, 2019).

Fig. 2–1. Agroforestry priorities: Temperate and tropical.

Table 2–1. Global definitions of agroforestry.

Region	Definition	Citation
Canada	“An approach to land use that incorporates trees into farming systems, and allows for the production of trees and crops or livestock from the same piece of land in order to obtain economic, ecological, environmental and cultural benefits”	Gordon and Newman, 1997
Global, Tropics	“The set of land use practices involve the deliberate combination of trees (including shrubs, palms and bamboos) and agricultural crops and/or animals on the same land management unit in some form of spatial arrangement or temporal sequence such that there are significant ecological and economic interactions between tree and agricultural components”	Sinclair, 1999
Australia	“Agroforestry is the commitment of resources by farmers, alone or in partnerships, towards the establishment or management of trees and forest on their land”	Reid and Moore, 2018
Global, Tropics	“Agroforestry is a dynamic, ecologically based, natural resource management system that, through the integration of trees on farms and in the agricultural landscape, diversifies and sustains smallholder production for increased social, economic and environmental benefits”	Garrity, 2005
Tropics	“Agroforestry is any land‐use system, practice or technology, where woody perennials are integrated with agricultural crops and/or animals in the same land management unit, in some form of spatial arrangement or temporal sequence”	Atangana et al., 2013
France	“The cultivation of the soil with a simultaneous or sequential association of trees and crops or animals to obtain products or services useful to man”	Torquebiau, 2000

Definition and Practices

       Definition

      In the United States and Canada, agroforestry is defined as: intensive land‐use management that optimizes the benefits (physical, biological, ecological, economic, social) from biophysical interactions created when trees and/or shrubs are deliberately combined with crops and/or livestock.

      This definition is slightly modified from Garrett et al. (1994) to improve compatibility with traditional agriculture. The main difference is the removal of the word “systems” from the definition. In tropical agroforestry and throughout much of the temperate zone, the use of