Frontiers in alley cropping: Transformative solutions for temperate agriculture

Abstract

Annual row crops dominate agriculture around the world and have considerable negative environmental impacts, including significant greenhouse gas emissions. Transformative land-use solutions are necessary to mitigate climate change and restore critical ecosystem services. Alley cropping (AC)-the integration of trees with crops-is an agroforestry practice that has been studied as a transformative, multifunctional land-use solution. In the temperate zone, AC has strong potential for climate change mitigation through direct emissions reductions and increases in land-use efficiency via overyielding compared to trees and crops grown separately. In addition, AC provides climate change adaptation potential and ecological benefits by buffering alley crops to weather extremes, diversifying income to hedge financial risk, increasing biodiversity, reducing soil erosion, and improving nutrient- and water-use efficiency. The scope of temperate AC research and application has been largely limited to simple systems that combine one timber tree species with an annual grain. We propose two frontiers in temperate AC that expand this scope and could transform its climate-related benefits: (i) diversification via woody polyculture and (ii) expanded use of tree crops for food and fodder. While AC is ready now for implementation on marginal lands, we discuss key considerations that could enhance the scalability of the two proposed frontiers and catalyze widespread adoption.

Black walnut alley cropping is economically competitive with row crops in the MidwestUSA

“…Furthermore, AC resilience to future climate change could be improved by enhancing traditional AC with multiple woody species and tree crops for food or fodder (Wolz et al. ).…”

Germplasm Development of Underutilized Temperate U.S. Tree Crops

“…Collectively, such marginal lands represent millions of underutilized hectares throughout the Midwest U.S. [35], which possess varying characteristics that cause marginality. Select tree crops have been described as compliments to the complex row-crop landscape [7,10,14] in that they are low-input [36][37][38] and suited to attributes typical of certain marginal land types (e.g., highly erodible, sloped lands) [10,39]. However, in practice, the extent to which particular tree crop selections are well suited to marginal lands remains to be determined.…”

“…A growing body of research suggests a path to increase the adoption of U.S. agroforestry systems lies in the integration of low-input fruit and nut producing tree species (henceforth, referred to as tree crops) [1,[7][8][9][10][11][12][13][14]. Such systems, described by Lovell et al [7], provide a unique opportunity to integrate new food production capacity into the Corn Belt while simultaneously providing regulatory services [7,14]. A primary constraint in considering these systems more broadly is the limited availability of tree crop germplasm and the extent to which cultivated selections can be improved and adapted to target environments across the Midwest U.S.…”

Autumn growth of three perennial weeds at high latitude benefits from climate change

“…Human activities shape and steer agro-ecosystems. Altered land use due to climate changes will further alter these systems (Trnka et al, 2011;Wolz et al, 2017). Extreme weather events and changes in climate variability may have large impacts on weeds and other pests (Thornton, Ericksen, Herrero, & Challinor, 2014).…”