Perennial Staple Crops: Yields, Distribution, and Nutrition in the Global Food System

Abstract

Staple crops, which have large amounts of carbohydrates, proteins, and/or fats, provide the bulk of calories in people's diets. Perennial plants, which can be productive for many years without the need for replanting, can produce staple foods and environmental benefits, but their agronomic and nutritional properties haven't been considered synthetically in comparison to annual staples. Here we offer a framework to classify perennial staple crops according to their nutritional categories and cultivation status. We assemble literature to report on the yield potential of 51 perennial staple crops, only 15 of which are well-characterized in existing global datasets. We show the extent and distribution of perennial staple crop production in relation to annual crop types, calculate the carbon stocks they hold, and analyze their nutritional content for three macronutrients and nine micronutrients. We found that most perennial staple crops are regional crops (not globally traded) that grow in the subtropics to tropics. At least one perennial staple crop in each of the five nutritional categories has yields over 2.5 t/ha, in some cases considerably higher, competitive with and in many cases exceeding those of nutritionally comparable annual staples. Perennial staple crops only comprise ~4.5% of total cropland. They hold a modest ~11.4 GtC above and below ground, less than one third of the anthropogenic carbon-equivalent emissions for the year 2018, but more than the ~9 GtC held by the same amount of annual cropland. If linear growth in land under perennial staple production continues to 2040, and replaces only annual cropland, an additional ~0.95 GtC could be sequestered. Many perennial crops also had competitive macronutrient density and yield (per unit area) compared to annual staples; moreover, specific perennial staples are abundant in specific micronutrients, indicating that they can be a nutrient-dense part of diets, unlike the most ubiquitous annual staple crops (corn, wheat, rice) that do not appear in the top 85th percentile for any of the nine micronutrients analyzed. Transition of land and diets to perennial staple crops, if judiciously managed, can provide win-win solutions for both food production and ecosystems.

Bioprospecting Microbiome for Soil and Plant Health Management Amidst Huanglongbing Threat in Citrus: A Review

“…Citrus is an important fruit crop, known globally to contribute significantly in economic, nutritional value, and health importance due to the abundance of the vital nutrient, antioxidants, minerals, vitamins, and dietary fibers present in the juice and fresh fruits ( Kreitzman et al, 2020 ). Above all, the distinct flavors of citrus fruits are extensively preferred and recognized throughout the world ( Wang et al, 2017 ; Trivedi et al, 2021 ).…”

Woody perennial polycultures in the U.S. Midwest enhance biodiversity and ecosystem functions

“…up with these properties as the perennial fields mature. Recent meta-analysis shows that perennial crops generally have higher soil carbon (Ledo et al 2020) and also hold significant biomass carbon (Kreitzman et al 2020) compared to annual agricultural land cover. The lack of temporal significance and small effect sizes of the soil chemical properties in our study are perhaps not surprising given the fairly small sample of mostly young perennial plantings.…”

“…The uses of conventional corn/soy agriculture are chiefly animal feed and biofuels, while the food produced on the perennial farms was nearly all for human consumption. The caloric comparisons we made are fair through the lens of land use in a particular geography, but they do not take into account the non-equivalence of all calories in terms of nutrient density (Kreitzman et al 2020), and the actual food needs of midwestern and international communities (Cassidy et al 2013). Studies are increasingly showing that food security is dictated by accessibility and affordability of food rather than its absolute production or availability, which is currently in surplus globally for all major macro and micronutrients (Ritchie et al 2018).…”

“…Thus, even without direct measurement of service units and monetary valuations, data about the environmental and agronomic outcomes of woody perennial polyculture systems are a necessary first step for future work that can evaluate the role of more widespread transition to perennial food systems (e.g., Figure 6 in Wolz et al 2017). Like in other forms of agroforestry, the opportunities for multifunctionality of perennial crop-based agroecosystems are many (Baptista et al 2007, Martins et al 2011, with the added dimension that these systems are primarily about growing food, including in many cases perennial staple crops (Kreitzman et al 2020), directly for people.…”

Modelling potential range expansion of an underutilised food security crop in Sub-Saharan Africa

“…However, a complementary strategy, which may be particularly pertinent under climate change, is the adaptation of agricultural systems through crop and cultivar choice (Rippke et al 2016;Mcmullin et al 2019;Pironon et al 2019;Rising and Devineni 2020). For example, recent evidence suggests that prioritising traits such as perenniality (Kreitzman et al 2020), tolerance to drought or heat-induced stress (Heider et al 2020) as well as crop diversity and asynchrony (Mcmullin et al 2019;Renard and Tilman 2019;Egli et al 2020) may help support smallholder resilience. Considering the antiquity and diversity of SSA agriculture, renewed investigation of orphan and underutilised indigenous crops may yield candidates with useful traits, where expanded cultivation could help meet food and nutritional security goals (Shelef et al 2017;Tadele and Bartels 2019;Ulian et al 2020).…”