Temperate agroforestry research: considering multifunctional woody polycultures and the design of long-term field trials

Abstract

The many benefits of agroforestry are well-documented, from ecological functions such as biodiversity conservation and water quality improvement, to cultural functions including aesthetic value. In North American agroforestry, however, little emphasis has been placed on production capacity of the woody plants themselves, taking into account their ability to transform portions of the landscape from annual monoculture systems to diversified perennial systems capable of producing fruits, nuts, and timber products. In this paper, we introduce the concept of multifunctional woody polycultures (MWPs) and consider the design of long-term experimental trials for supporting research on agroforestry emphasizing tree crops. Critical aspects of long-term agroforestry experiments are summarized, and two existing well-documented research sites are presented as case studies. A new long-term agroforestry trial at the University of Illinois, “Agroforestry for Food,” is introduced as an experiment designed to test the performance of increasingly complex woody plant combinations in an alley cropping system with productive tree crops. This trial intends to address important themes of food security, climate change, multifunctionality, and applied solutions. The challenges of establishing, maintaining, and funding long-term agroforestry research trials are discussed

Exploring the potential of edible forest gardens: experiences from a participatory action research project in Sweden

“…Experiences from the PAR project, which were supported by the findings by Lowell et al (2017), point to the crucial knowledge gaps concerning potential production as well as the ecological value of edible forest gardens in temperate areas. There is a lack of data on the yields of specific species when they are grown in monoculture as well as regarding the yields of species in intercropping conditions.…”

“…The group called for structured breeding work to be organized on a regional basis. Lowell et al (2017) also anticipated that improved tree crop varieties might "boost the overall performance of the system", and Clark and Nicholas (2013) started this work by identifying species that may be suitable due to cold hardiness, drought tolerance and edibility. The group further identified the need for research on the interactions between the forest garden plants and the above and below ground wild biotic community, e.g., biological regulation due to predation, parasitism, symbiosis and allelopathy.…”

Temperate Agroforestry: How Forest Garden Systems Combined with People-Based Ethics Can Transform Culture

“…To aid in the formation of long-term field trials for woody perennial polyculture systems, Lovell et al [7] have developed research design processes that consider the respective needs of farmers and research facilities. It comprehensively lays out components of experimental designs (tools for diverse perennial planning, issues to consider, next steps needed, etc.)…”

“…The goals of FGSs are to prioritize local needs of humans by achieving a state of abundant diverse yields, self-fertilization, self-maintenance, and self-renewal, as well as healing the land from past and present degradation [4,5,7]. In combination with design frameworks (i.e., cultural principles) that prioritize people, the land, and the water, FGSs have the potential to rehabilitate food systems and grow communities that thrive alongside the ecologies they are in relationship with.…”

“…Additional grower-based reasons include: lack of research demonstrating the yield potentials of many perennials, especially within a polyculture and with multiple vertical layers; how to use and or market multiple plants; uncertainty around the design process with diverse perennial plants and site-specificity with few long term examples to model after, especially on larger area scale. Farming and forestry practices, policies, and markets have been separated from each other making it more complicated for growers [7]. Also, some growers perceive the costs for establishing perennials, and the necessary skill-base to manage them, as a risk for profitability with agroforestry yields [13].…”