1. The many problems of annual grain production

The Neolithic Revolution 12,000 to 7000 years ago, during which humans shifted from hunting and gathering to farming, was arguably the most decisive social transition in human history in terms of path dependency. This profound shift in the provision of food marked the rise of civilizations and the beginning of political organizations (Weisdorf, Reference Weisdorf2005), and was by some proposed as the onset of a new geological Epoch, the Anthropocene (Lewis & Maslin, Reference Lewis and Maslin2015). Its most important characteristic was the domestication of the annual grasses and forbs that still comprise the mainstay of our food, such as wheat, rice, maize, soya (together representing 50% of world croplands), barley, beans, millet, oat, rye, sesame, sorghum, and sunflower. It is hard to overstate the importance of agriculture for the development of civilization, but now agriculture and the world's food supply have reached a critical crossroad (Olsson et al., Reference Olsson, Crews, Franklin, King, Mirzabaev, Scown, Tengberg, Villarino and Wang2023).

The history of domestication has so far resulted in that most humans today depend on a few high-yielding staple crops in agricultural systems that are unsustainable (McIntyre et al., Reference McIntyre, Herren, Wakhungu and Watson2009), climate vulnerable (Bezner Kerr et al., Reference Bezner Kerr, Hasegawa, Lasco, Bhatt, Deryng, Farrell, Gurney-Smith, Ju, Lluch-Cota, Meza, Nelson and Neufeldt2022), nutrient poor (FAO et al., 2020; Gillespie et al., Reference Gillespie, van den Bold Gillespie and van den Bold2017), and inequitable (Krug et al., Reference Krug, Drummond, Van Tassel and Warschefsky2023). The global demand for food is projected to continue to increase because of a burgeoning population, shifting dietary preferences, over-consumption, and food wastage (van Dijk et al., Reference van Dijk, Morley, Rau and Saghai2021). The size of the demand for food by 2100 is contested, from a doubling, as argued by agroindustry (Steensland, Reference Steensland2021) to 40–55% as assumed by the FAO (FAO, 2019), and as low as 30% as suggested by some integrated models (van Dijk et al., Reference van Dijk, Morley, Rau and Saghai2021). Climate change, water scarcity, and land use change are expected to make it difficult to meet even the lowest of increased demands (Bezner Kerr et al., Reference Bezner Kerr, Hasegawa, Lasco, Bhatt, Deryng, Farrell, Gurney-Smith, Ju, Lluch-Cota, Meza, Nelson and Neufeldt2022; Mbow et al., Reference Mbow, Rosenzweig, Barioni, Benton, Herrero, Krishnapillai, Liwenga, Pradhan, Rivera-Ferre, Sapkota, Tubiello, Xu, Shukla, Skea and Al2019; Olsson et al., Reference Olsson, Barbosa, Bhadwal, Cowie, DeLusca, Flores-Renteria, Hermans, Jobbagy, Kurz, Li, Sonwa, Stringer, Shukla, Skea, Calvo Buendia, Masson-Delmotte, Pörtner, Roberts, Zhai, Slade, Connors, van Diemen, Ferrat, Haughey, Luz, Neogi, Pathak, Petzold, Portugal Pereira, Vyas, Huntley and Malley2019). Moreover, agriculture is already one of the most polluting sectors of society (Breitburg et al., Reference Breitburg, Levin, Oschlies, Grégoire, Chavez, Conley, Garçon, Gilbert, Gutiérrez, Isensee, Jacinto, Limburg, Montes, Naqvi, Pitcher, Rabalais, Roman, Rose, Seibel and Zhang2018; Foley et al., Reference Foley, Ramankutty, Brauman, Cassidy, Gerber, Johnston, Mueller, O'Connell, Ray, West, Balzer, Bennett, Carpenter, Hill, Monfreda, Polasky, Rockström, Sheehan, Siebert and Zaks2011; Ramankutty et al., Reference Ramankutty, Mehrabi, Waha, Jarvis, Kremen, Herrero and Rieseberg2018), and dominant trends in the sector are at odds with social goals such as health (Clark et al., Reference Clark, Springmann, Hill and Tilman2019), employment (White, Reference White2012), livelihood diversity, and social cohesion (Losch et al., Reference Losch, Freguin-Gresh and White2012). Most people living in extreme poverty are rural and employed in agriculture, a sector characterized by inequality and gender disparities (World Bank, Reference World Bank2018). In high-income countries farmers suffer from high and increasing debts, decreasing returns, and high levels of stress (Rudolphi, Reference Rudolphi2019; Rudolphi & Barnes, Reference Rudolphi and Barnes2019). At a very different level, agriculture is also the main culprit of the 400+ marine dead zones in coastal waters (Bailey et al., Reference Bailey, Meyer, Pettingell, Macie, Korstad, Bauddh, Kumar, Singh and Korstad2020; Foley et al., Reference Foley, Ramankutty, Brauman, Cassidy, Gerber, Johnston, Mueller, O'Connell, Ray, West, Balzer, Bennett, Carpenter, Hill, Monfreda, Polasky, Rockström, Sheehan, Siebert and Zaks2011). These challenges combined make a radical change in the agricultural sector imperative, and such a change must also respond to the increasing demands and expected deteriorating productivity due to climate change (Bezner Kerr et al., Reference Bezner Kerr, Hasegawa, Lasco, Bhatt, Deryng, Farrell, Gurney-Smith, Ju, Lluch-Cota, Meza, Nelson and Neufeldt2022; Challinor et al., Reference Challinor, Watson, Lobell, Howden, Smith and Chhetri2014; Mbow et al., Reference Mbow, Rosenzweig, Barioni, Benton, Herrero, Krishnapillai, Liwenga, Pradhan, Rivera-Ferre, Sapkota, Tubiello, Xu, Shukla, Skea and Al2019; Porter et al., Reference Porter, Xie, Challinor, Cochrane, Howden, Iqbal, Lobell, Travasso, Netra, Garrett, Ingram, Lipper, McCarthy, McGrath, Smith, Thorton, Watson, Ziska, Field, Barros, Dokken, Mach, Mastrandrea, Bilir, Chatterjee, Ebi, Otsuki Estrada, Genova, Girma, Kissel, Levy, MacCracken and Mastrandrea2014) and the nutritional quality of food (Zhu et al., Reference Zhu, Kobayashi, Loladze, Zhu, Jiang, Xu, Liu, Seneweera, Ebi, Drewnowski, Fukagawa and Ziska2018).

Modern agriculture is unsustainable first and foremost because of the reliance on low diversity annual cropping systems that require severe disruption of soil ecosystems every year to restart the production cycle (Baker, Reference Baker2017; Crews et al., Reference Crews, Carton and Olsson2018; Crews & Rumsey, Reference Crews and Rumsey2017; Eisler, Reference Eisler2019; Lubofsky, Reference Lubofsky2016; Rasche et al., Reference Rasche, Blagodatskaya, Emmerling, Belz, Musyoki, Zimmermann and Martin2017; Soto-Gómez & Pérez-Rodríguez, Reference Soto-Gómez and Pérez-Rodríguez2022). This is arguably a root cause of both environmental damage (erosion, nutrient leaching, greenhouse gas emissions, deteriorating soil biodiversity, and spreading of toxic substances) and many social predicaments, such as the high dependence on an industry of external inputs (seeds, agrochemicals, machinery, and fossil fuel). This makes agriculture a cost to society through a complex system of subsidies totaling about $600 billion per year worldwide (Laborde et al., Reference Laborde, Mamun, Martin, Piñeiro and Vos2021), or in the EU, about 35% of its total budget (Head, Reference Head2019; Scown et al., Reference Scown, Brady and Nicholas2020).

In order to attribute these predicaments to one specific factor, the reliance on annual grains, we turn to the concept path dependence for understanding the historical evolution of agriculture (Mahoney, Reference Mahoney2000). One reason why annual crops are favored in commercial plant breeding, is the opportunity to use patent protection as a way of reaping future benefits. Even if plants were exempted from the original patent legislation in 1836, the discovery of methods for creating hybrid seeds in the 1920s paved the way for patentability of seeds, and in 1930 the first patent of a seed was granted. The arguments for patentability of plants were primarily industrial (Seay, Reference Seay1988). Even if crops superior to the hybrids could have been achieved through selection of (not patentable) open-pollinates (Kloppenburg, Reference Kloppenburg2005; Paul, Reference Paul1989), the plant breeding industry focused on hybrids because of their patentability and hence commercial potential. Therefore, we can consider the 1930s decision to allow patents on plants as a contingent moment initiating a self-reinforcing sequence of plant breeding techniques (Mahoney, Reference Mahoney2000).

Agriculture has historically developed in both radical leaps (revolutions) and incremental changes. In the last 150 years we have distinguished at least four technological breakthroughs, sometimes referred to as revolutions, but with very different political and economic implications. The first was the invention and mass manufacture of the moldboard plow in the 1850s. With the steel plow it was possible to plow deeper into heavy soils, and to turn the soil over. This facilitated the expansion of agriculture into new areas. The second was the Haber Bosch process to manufacture plant-available nitrogen from atmospheric nitrogen in the 1910s (Smil, Reference Smil2004). The third was the Green Revolution in the 1960s which was primarily driven by advances in plant breeding supported by massive use of agrochemicals for the purpose of eradicating hunger (Evenson & Gollin, Reference Evenson and Gollin2003). The fourth agricultural revolution was the transgenic revolution primarily oriented towards producing new crops with agronomic traits to make cropping more cost effective – nearly all the commercially released transgenic crops are either herbicide tolerant or insect resistant varieties (van Acker et al., Reference van Acker, Rahman and Cici2017). These four revolutions have increased food production, averted famine, increased food security, and improved lives in many farming communities. Yet, over a longer time perspective the legacy of these agricultural revolutions is increasingly contested both in terms of the environmental trade-offs and social ramifications (Stone, Reference Stone2019). All four agricultural revolutions also contributed to creating the economic conditions that drive agriculture towards productivism, as will be elaborated below. In sum, modern agriculture is increasingly unable to generate desired benefits without negative costs, and its viability is increasingly undermined by climate change.

2. The many calls for a new agricultural vision

There is growing momentum in the UN (FAO et al., 2020), EU (Kelly & Naujokaityte, Reference Kelly and Naujokaityte2020), and USA (USDA, 2021) of the necessity for agriculture to change in order to better balance production of goods with conservation of natural resources. However, most of the proposed changes are incremental without addressing a root cause of unsustainability, namely the reliance on annual crops. Below we briefly review some of the most common discourses of sustainable agriculture, many of which overlap.

• • Climate-smart agriculture is a broad approach for transforming and reorienting agricultural systems to support food security under the new conditions expected from climate change and water scarcity. Even if climate-smart agriculture is loosely defined and interpretations differ among stakeholders, three pillars are foundational: sustainably increase food production; adapting and building resilience to climate change; reducing emission of greenhouse gases and/or remove emissions where possible (Alexander, Reference Alexander2019; Lipper et al., Reference Lipper, Thornton, Campbell, Baedeker, Braimoh, Bwalya, Caron, Cattaneo, Garrity, Henry, Hottle, Jackson, Jarvis, Kossam, Mann, McCarthy, Meybeck, Neufeldt, Remington and Torquebiau2014).

• • Sustainable/ecological intensification is a related umbrella term for various ways of changing agricultural practices to increase crop yield while reducing the environmental impact of agriculture (Pretty, Reference Pretty2018). It is often emphasizing crop diversity (Bommarco et al., Reference Bommarco, Kleijn and Potts2013), and includes the debate on land sharing/sparing (Phalan et al., Reference Phalan, Onial, Balmford and Green2011).

• • Smart Farming is an umbrella term that includes ‘precision agriculture’ for harnessing the exponentially increasing use of information and communication technologies (ICT) for optimizing and automatizing farming to deliver water, nutrients, and pesticides at targeted locations, rates, and timings (Walter et al., Reference Walter, Finger, Huber and Buchmann2017).

• • Organic agriculture is a term used explicitly for production systems that do not allow use of synthetic fertilizers and pesticides and instead rely on animal manure, biological fixation, and biological pest control practices, or naturally derived biocides (Howard, Reference Howard1947; Reganold & Wachter, Reference Reganold and Wachter2016). Organic agriculture is a holistic production management system which promotes and enhances agroecosystem health, including biodiversity, biological cycles, and soil biological activity. This production system is primarily consumer driven and supported by international regulation standards.

• • Regenerative agriculture is a broad term generally used to describe practices that improve soil quality through 1) minimal disturbance, 2) continuous cover by mulch and cover crops, 3) diversity in terms of crop rotation and intercropping (Giller et al., Reference Giller, Hijbeek, Andersson and Sumberg2021; Montgomery, Reference Montgomery2017; Rhodes, Reference Rhodes2013). This term is increasingly adopted by disparate groups ranging from grass roots farmer and rancher organizations to governmental and development agencies, as well as corporations (Tittonell et al., Reference Tittonell, El Mujtar, Felix, Kebede, Laborda, Luján Soto and de Vente2022).

Importantly, these discourses have particular institutional links, both private and public. Climate Smart Agriculture is a concept primarily promoted by international organizations such as FAO, World Bank and the CGIAR. Smart Farming is heavily promoted by agricultural technology companies (agrochemicals and machinery). Organic agriculture originated as a biophilic philosophy that has since the early 1990s been codified as a business concept based on third party certification of products. Regenerative agriculture started as a social movement among farmers that is rapidly spreading to other sectors, and risks losing its original meaning (Bless et al., Reference Bless, Davila and Plant2023).

A fallacy, however, of all these approaches, at least from a soil carbon perspective, is the assumption that reversing degradation will restore soil carbon levels. It is well known that frequent and deep tillage in combination with leaving the soil surface exposed for long periods of time releases soil carbon to the atmosphere (Chi et al., Reference Chi, Waldo, Pressley, O'Keeffe, Huggins, Stöckle, Pan, Brooks and Lamb2016). But this does not mean that the soil carbon will come back if these detrimental practices are reversed. The soil carbon that accumulated in soils prior to cultivation were built by a diversity of perennial plants with dense and deep root systems. Only by reintroducing a diversity of deep-rooted plants can we hope to rebuild that soil carbon (Guan et al., Reference Guan, Turner, Song, Gu, Wang and Li2016; Ledo et al., Reference Ledo, Smith, Zerihun, Whitaker, Vicente-Vicente, Qin, McNamara, Zinn, Llorente, Liebig, Kuhnert, Dondini, Don, Diaz-Pines, Datta, Bakka, Aguilera and Hillier2020).

3. A perennial revolution as a new radical alternative

We argue that the agricultural systems that hold the greatest promise for improving on all unsustainable dimensions of annual grain agriculture are systems that feature perennial grains cultivated in mixtures – here called perennial polycultures (Baker, Reference Baker2017; Chapman et al., Reference Chapman, Thomsen, Tulloch, Correia, Luo, Najafi, DeHaan, Crews, Olsson, Lundquist, Westerbergh, Pedas, Knudsen and Palmgren2022; Crews et al., Reference Crews, Carton and Olsson2018; de Oliveira et al., Reference de Oliveira, Brunsell, Crews, DeHaan and Vico2019; Duchene et al., Reference Duchene, Celette, Ryan, DeHaan, Crews and David2019; Ryan et al., Reference Ryan, Crews, Culman, DeHaan, Hayes, Jungers and Bakker2018; Soto-Gómez & Pérez-Rodríguez, Reference Soto-Gómez and Pérez-Rodríguez2022). We argue that a perennial revolution is essential for long-term sustainable agriculture.

In envisioning this alternative to current agriculture, we take inspiration from Erik Olin Wright's framework for social change, ‘envisioning real utopias’ (Wright, Reference Wright2010). This involves a three-pronged approach:

• • A theoretically profound and systematic analysis of the current state-of-play. This means that we need to go beyond discussing the problems as such and ask the more fundamental question of why modern agriculture developed into the current system. What were the conditions and drivers of agriculture?

• • The formulation of an alternative to the current situation that is desirable (i.e. that it can generate the benefits we envision without negative side effects in terms of environment, agricultural communities, and society at large); viable (i.e. that it can be sustained over long periods of time without shifting problems into the future); and achievable (i.e. that it can be achieved in a reasonable timeframe).

• • A strategy for change by which the current system can be transformed into the new alternative. Such a strategy may have to first undermine or erode the power of the incumbent systems in order to pave the way for the new alternative (Wright, Reference Wright2019).

The realization of diverse, perennial grain agricultural systems would be revolutionary for both ecological and social reasons. Ecologically, novel agroecosystems of perennial polycultures could help repair the ecosystem harms of industrial annual agriculture and could help restore and retain vitally necessary natural ecosystem services while producing food for humans (Crews et al., Reference Crews, Carton and Olsson2018). Socially, a perennial revolution could fundamentally challenge the power structures that drive current agriculture by rendering much of the current agricultural inputs industry less important, or in some cases even superfluous, through agroecological transitions balancing production and environmental protection (Duru et al., Reference Duru, Therond and Fares2015). The more sustainable ecological, economic, and energetic infrastructure provided by perennial agriculture opens ethical possibilities for more just human cultures and relationships; while a ‘social perennial vision’ is not inevitable, it can be intentionally pursued (Krug & Tesdell, Reference Krug and Tesdell2021).

When the idea of shifting from annual crops to perennial crops was first expressed some 40 years ago (Eisler, Reference Eisler2019; Jackson, Reference Jackson1980) it was regarded by many as utopian. However, advances in plant breeding across subsequent decades have shown that it is possible to rapidly develop new perennial crops through wide hybridization of existing annual plants with wild perennial relatives (Cox et al., Reference Cox, Nabukalu, Paterson, Kong and Nakasagga2018; Cui et al., Reference Cui, Ren, Murray, Yan, Guo, Niu, Sun and Li2018; Zhang et al., Reference Zhang, Huang, Zhang, Huang, Cheng, Wang, Zhang, Wang, Zhu, Yu, Tao, Hu, Yang, Qi, Li, Liu, Yang, Long, Harnpichitvitaya and Hu2019) and an alternative strategy, de novo domestication of wild plants now also seems possible (Chapman et al., Reference Chapman, Thomsen, Tulloch, Correia, Luo, Najafi, DeHaan, Crews, Olsson, Lundquist, Westerbergh, Pedas, Knudsen and Palmgren2022; Luo et al., Reference Luo, Najafi, Correia, Trinh, Chapman, Østerberg, Thomsen, Pedas, Larson, Gao, Poland, Knudsen, DeHaan and Palmgren2022). However, in a situation where most of the plant breeding is funded by the private sector looking for a return on investment, there is little economic incentive to develop perennial grains (Clancy & Moschini, Reference Clancy and Moschini2017; Coe et al., Reference Coe, Evans, Gasic and Main2020).

Doubts about and even objections to the idea of domesticating perennial grain crops (Denison, Reference Denison2012; Loomis, Reference Loomis2022; Smaje, Reference Smaje2015), are sometimes raised by referring to the phenotypic trade-off theory (or the ‘Y-model’) in ecology, popular in the 1980s and 90s (Roff & Fairbairn, Reference Roff and Fairbairn2007; Roff & Gelinas, Reference Roff and Gelinas2003). According to this theory perennial plants do not allocate enough energy to producing large seeds, but instead prioritize other plant functions, such as vegetative growth and soil exploration through an extensive root system. However, observed phenotypic trade-offs are not always supported by evolutionary theory because it is possible that natural selection in a competitive environment never favored the development of both longevity (large root system of perennials) and reproductive capacity (many spikes and large seeds) (Garland, Reference Garland2014). More recent research suggests that a quantitative genetic theory is a more appropriate for understanding trade-offs, and according to this theory plant breeding can promote both longevity (roots) and reproductive capacity (seeds). Evidence exists that the trade-off between perenniality and reproductive allocation is not fixed, for example, herbaceous perennial crops that produce 20 tons (plantain) to 50 tons (banana) of fruit per ha in the tropics (Kreitzman et al., Reference Kreitzman, Toensmeier, Chan, Smukler and Ramankutty2020). Olive trees, domesticated about 6000 years ago, sustain their yields for 300 to 500 years (Camarero et al., Reference Camarero, Colangelo, Gracia-Balaga, Ortega-Martínez and Büntgen2021). Wild perennial plants produce fewer or smaller seeds because of natural selection in a competitive environment where longevity is favored rather than because of physiologically optimized allocation (DeHaan et al., Reference DeHaan, Van Tassel and Cox2005). So even if most existing agricultural crops are annuals, there is no biological reason preventing the domestication of perennial grain crops (Bajgain et al., Reference Bajgain, Crain, Cattani, Larson, Altendorf, Anderson, Crews, Hu, Poland, Turner, Westerbergh, DeHaan and Goldman2022; Chapman et al., Reference Chapman, Thomsen, Tulloch, Correia, Luo, Najafi, DeHaan, Crews, Olsson, Lundquist, Westerbergh, Pedas, Knudsen and Palmgren2022; Ciotir et al., Reference Ciotir, Applequist, Crews, Cristea, DeHaan, Frawley, Herron, Magill, Miller, Roskov, Schlautman, Solomon, Townesmith, Van Tassel, Zarucchi and Miller2019; DeHaan et al., Reference DeHaan, Van Tassel and Cox2005, Reference DeHaan, Van Tassel, Anderson, Asselin, Barnes, Baute, Cattani, Culman, Dorn, Hulke, Kantar, Larson, David Marks, Miller, Poland, Ravetta, Rude, Ryan, Wyse and Zhang2016; DeHaan & Van Tassel, Reference DeHaan and Van Tassel2014; Van Tassel et al., Reference Van Tassel, Tesdell, Schlautman, Rubin, DeHaan, Crews and Streit Krug2020). However, if we use a political ecology lens the phenotypic trade-off theory can justify and support a continuation of conventional annual crops.

That a perennial revolution is possible can be illustrated by two recent developments: Kernza® grain, which is the result of domestication and traditional breeding of the wild perennial grass intermediate wheatgrass (hereafter called IWG; Thinopyrum intermedium) (Bajgain et al., Reference Bajgain, Zhang, Jungers, DeHaan, Heim, Sheaffer, Wyse and Anderson2020), and perennial rice which is the result of species-wide hybridization of Asian cultivated rice (Oryza sativa ssp. indica) with the African wild perennial relative Oryza longistaminata (Zhang et al., Reference Zhang, Huang, Zhang, Lv, Wan, Liang, Feng, Dao, Wu, Zhang, Yang, Lian, Huang, Shao, Zhang, Qin, Tao, Crews, Sacks, Wade and Hu2023). The evidence from IWG is that grain yield and other domestication traits such as seed size, shatter resistance, and free threshing ability (i.e. that the seed separates cleanly from the chaff when threshing) can be increased rapidly in a previously wild perennial species using traditional breeding and modern genetic tools such as genomic selection (Fagnant et al., Reference Fagnant, Duchêne, Celette, David, Bindelle and Dumont2023; LeHeiget et al., Reference LeHeiget, McGeough, Biligetu and Cattani2023). The evidence from perennial rice is that wide hybridization of an existing annual crop and a perennial wild relative can generate a high yielding perennial crop. These proofs-of-concept are major and significant achievements, but many more perennial grain crops and cultivars are in the pipeline (Chapman et al., Reference Chapman, Thomsen, Tulloch, Correia, Luo, Najafi, DeHaan, Crews, Olsson, Lundquist, Westerbergh, Pedas, Knudsen and Palmgren2022; Crews et al., Reference Crews, Blesh, Culman, Hayes, Jensen, Mack, Peoples and Schipanski2016). Within one to three decades we expect to see a wide range of perennial grain crops making inroads into agriculture and becoming operational, such as barley, oil seeds, sorghum, wheat and legumes (Baker, Reference Baker2017; Ciotir et al., Reference Ciotir, Applequist, Crews, Cristea, DeHaan, Frawley, Herron, Magill, Miller, Roskov, Schlautman, Solomon, Townesmith, Van Tassel, Zarucchi and Miller2019; Crews et al., Reference Crews, Carton and Olsson2018; DeHaan et al., Reference DeHaan, Van Tassel, Anderson, Asselin, Barnes, Baute, Cattani, Culman, Dorn, Hulke, Kantar, Larson, David Marks, Miller, Poland, Ravetta, Rude, Ryan, Wyse and Zhang2016, Reference DeHaan, Larson, López-Marqués, Wenkel, Gao and Palmgren2020; Luo et al., Reference Luo, Najafi, Correia, Trinh, Chapman, Østerberg, Thomsen, Pedas, Larson, Gao, Poland, Knudsen, DeHaan and Palmgren2022; Westerbergh et al., Reference Westerbergh, Lerceteau-Köhler, Sameri, Bedada and Lundquist2018). Doubts about the lack of progress in breeding perennial grains were raised recently by Cassman & Connor (Cassman & Connor, Reference Cassman and Connor2022), but are contradicted by recent research showing rapid improvements in yield and other agronomic traits (Altendorf et al., Reference Altendorf, DeHaan and Anderson2022; Bajgain et al., Reference Bajgain, Crain, Cattani, Larson, Altendorf, Anderson, Crews, Hu, Poland, Turner, Westerbergh, DeHaan and Goldman2022; DeHaan et al., Reference DeHaan, Anderson, Bajgain, Basche, Cattani, Crain, Crews, David, Duchene, Gutknecht, Hayes, Hu, Jungers, Knudsen, Kong, Larson, Lundquist, Luo, Miller and Westerbergh2023).

A fundamental difference between annual and perennial plants is the root system (Roumet et al., Reference Roumet, Urcelay and Díaz2006). Annuals develop roots just for one season whereas perennials build and accumulate typically deeper and wider root systems over numerous years (Culman et al., Reference Culman, DuPont, Glover, Buckley, Fick, Ferris and Crews2010; Duchene et al., Reference Duchene, Celette, Barreiro, Mårtensson, Freschet and David2020; Monti & Zatta, Reference Monti and Zatta2009; Sainju et al., Reference Sainju, Allen, Lenssen and Ghimire2017). In Figure 1 we show the difference between the annual winter wheat ready to be harvested (left) compared with the newly domesticated perennial grain IWG after two seasons. One study has shown that root systems of IWG in its fourth year of growth were 15 times larger by weight and size than wheat (Sprunger et al., Reference Sprunger, Culman, Robertson and Snapp2018). Eddy covariance measurements have demonstrated that IWG can act as a strong carbon sink – the mean annual flux from the atmosphere was about 14 tons CO₂ ha⁻¹ year⁻¹ (370 g C m⁻²) over a five-year period (de Oliveira et al., Reference de Oliveira, Brunsell, Sutherlin, Crews and DeHaan2018, Reference de Oliveira, Brunsell, Crews, DeHaan and Vico2019). Exactly how much of the assimilated carbon that remains in the soil for long periods of time is still a matter of discussion (Gregory, Reference Gregory2022; Peixoto et al., Reference Peixoto, Olesen, Elsgaard, Enggrob, Banfield, Dippold, Nicolaisen, Bak, Zang, Dresbøll, Thorup-Kristensen and Rasmussen2022). The extensive root system is also the reason why perennial crops reduce nutrient leaching to ground water, streams, lakes and ultimately oceans to virtually zero (Cosentino et al., Reference Cosentino, Copani, Scalici, Scordia and Testa2015; Culman et al., Reference Culman, Snapp, Ollenburger, Basso and DeHaan2013; DeHaan et al., Reference DeHaan, Van Tassel and Cox2005; Huddell et al., Reference Huddell, Ernfors, Crews, Vico and Menge2023; Jankauskas et al., Reference Jankauskas, Jankauskiene and Fullen2011; Vallebona et al., Reference Vallebona, Mantino and Bonari2016). Hence, shifting from annuals to perennials would have a tremendous effect on water quality and eventually ocean health (Beman et al., Reference Beman, Arrigo and Matson2005; Beusen et al., Reference Beusen, Bouwman, Van Beek, Mogollón and Middelburg2016).

Figure 1. Intermediate wheatgrass in its second year (right) compared with winter wheat ready to be harvested (left). Photo: The Land Institute.

Weeds have been a persistent problem in agriculture since its beginning, indeed they are both an ecological response of, and a reason for clearing the land with tillage every year. More recently, herbicide use has increased substantially (Damalas & Koutroubas, Reference Damalas and Koutroubas2024), e.g., the most widely used herbicide (glyphosate) has increased almost 15-fold globally since the introduction of glyphosate resistant crops (Benbrook, Reference Benbrook2016). One could hope that the increasing use of glyphosate could be balanced by reduced use of other more toxic herbicides, such as paraquat, but does not seem to be the case (Olsson et al., Reference Olsson, Crews, Franklin, King, Mirzabaev, Scown, Tengberg, Villarino and Wang2023). As a result, we experience an exponential increase in the number of weeds that are resistant to glyphosate, often called ‘superweeds’ (Bain et al., Reference Bain, Selfa, Dandachi and Velardi2017; Damalas & Koutroubas, Reference Damalas and Koutroubas2024). Contrary to cropping systems based on annuals, perennial cropping systems, once they are established, can effectively suppress weeds by more fully utilizing the plant resources of sunlight, water, and nutrients. In a controlled experiment during three years, weed biomass decreased by 88% in an IWG field without any weed removal (Zimbric et al., Reference Zimbric, Stoltenberg and Picasso2020). Therefore, IWG could also reduce weed development and species abundance over time through year-round soil cover and longer growing seasons (Duchene et al., Reference DeHaan, Anderson, Bajgain, Basche, Cattani, Crain, Crews, David, Duchene, Gutknecht, Hayes, Hu, Jungers, Knudsen, Kong, Larson, Lundquist, Luo, Miller and Westerbergh2023). Lanker et al. (Reference Lanker, Bell and Picasso2020) confirmed that weed suppression was considered by farmers as one of the most important benefits.

Crop rotation is a common practice for reducing the risk of agricultural pests in annual cropping systems, and pathogen pressure is often used as a counterargument against perennial cropping systems. Deploying crop diversity in time (crop rotation) can effectively disrupt insect or disease pest populations and thus reduce crop losses. However, inbred annual cultivars with low genetic diversity and cultivated in monocultures are always susceptible to pests. Strategically deploying crop diversity (inter and intraspecific) in space (intercrops/polycultures) has also been widely recognized as an effective strategy for regulating insect and disease populations (Deguine et al., Reference Deguine, Aubertot, Flor, Lescourret, Wyckhuys and Ratnadass2021; Ratnadass et al., Reference Ratnadass, Fernandes, Avelino and Habib2012). In addition to interspecific diversity, genetic diversity within crop species in agroecosystems (as seen in outcrossers such as IWG and other perennials, or among mixtures of cultivars) reduces pest and disease pressures and enhances yield production (Wan et al., Reference Wan, Fu, Dainese, Hu, Pødenphant Kiær, Isbell and Scherber2022).

Even if perennial grains are used, they are likely to be renewed at intervals of 3–7 years. Reasons for this could be to remove weeds or that plant breeding has resulted in new and higher yielding cultivars. Studies have also suggested the possibility of rejuvenating old perennial cultures through thinning, burning, grazing or other treatments, but more research is needed (Law et al., Reference Law, Pelzer, Wayman, Ditommaso and Ryan2021; Pinto et al., Reference Pinto, De Haan and Picasso2021).

The application of nutrients, either in the form of mineral fertilizers or as manure is another costly and labor-intensive part of growing annual crops. Nitrogen is a problem, often added at a rate of 120 to 250 kg ha⁻¹year⁻¹, and the manufacture of synthetic nitrogen fertilizers comprises the greatest fossil energy input into agriculture, and a significant source of greenhouse gas emissions. It is well-documented that typically <50% of the fertilizer-N applied to annual grains is used by plants (Ladha et al., Reference Ladha, Pathak, Krupnik, Six and van Kessel2005, Reference Ladha, Tirol-Padre, Reddy, Cassman, Verma, Powlson, van Kessel, de Richter, Chakraborty and Pathak2016) while the rest is lost to the environment as water soluble nitrate or in various gaseous forms including ammonia and nitrous oxide (Cameron et al., Reference Cameron, Di and Moir2013; Sharma & Bali, Reference Sharma and Bali2018). Cropping systems that feature deep-rooted perennial grains cultivated in mixed cultures or rotations with nitrogen (atmospheric N₂) fixing legumes, such as clover or alfalfa, hold promise to drastically reduce or perhaps even replace the need for synthetic nitrogen applications (Huddell et al., Reference Huddell, Ernfors, Crews, Vico and Menge2023; Pugliese et al., Reference Pugliese, Culman and Sprunger2019). Fewer inputs through natural nitrogen fixation are needed when N losses are greatly reduced in an N-use efficient perennial cropping system. Phosphorous is another essential nutrient for crop production which is added in large quantities, typically 10–40 kg ha⁻¹ year⁻¹ in annual cropping systems. The known minable resources are finite and may be depleted in less than 100 years (Cordell et al., Reference Cordell, Drangert and White2009). However, agricultural soils commonly contain substantial reserves of phosphorus that are unavailable for our annual crops with shallow root systems. New perennial crops with deep and extensive root systems can potentially utilize such reserves (Stutter et al., Reference Stutter, Shand, George, Blackwell, Bol, MacKay, Richardson, Condron, Turner and Haygarth2012), and hence substantially reduce the need for external inputs of phosphorous. Also, with deeper roots natural reserves of phosphorus can be acquired from a larger soil volume, held in forms that are more plant-available, and prevented from contaminating water supplies due to soil erosion (Crews & Brookes, Reference Crews and Brookes2014). The ability of perennial grain crops to harness mycorrhiza for improved nutrient cycling is another potential major benefit (Duchene et al., Reference Duchene, Celette, Barreiro, Mårtensson, Freschet and David2020; Gregory, Reference Gregory2022; Strohm, Reference Strohm2021).

From a farming point of view, perennial grains could be described as a farmer's dream – a cultivar that is planted once and then harvested every season for several years with a minimum of land management in between. Instead of 4–10 tractor passes per year as with annual cultivars, only 1–5 for harvesting and nutrient, pest, and weed management, would be required. From a farm economics point of view, farming perennial grains could translate into a significant reduction in production costs, resulting in increasing total factor productivity. From a regional economic perspective, it could mean that a larger share of farmers' income would remain in the local economy as the need for purchased inputs such as seeds, agrochemicals, synthetic fertilizers, fuel, and machinery from external (often transnational) corporations are reduced. The retained income may stimulate local economic development through the creation of new businesses (Low et al., Reference Low, Adalja, Beaulieu, Key, Martinez, Melton, Perez, Ralston, Stewart, Suttles and Jablonski2015; Persky et al., Reference Persky, Ranney and Wiewel1993) that service the emerging perennial sector. Such local growth could play an important role in offering opportunities to workers in seasonal employment (i.e. tractor drivers) who may be displaced in the short run during this transition. In the long term, the transition to perennial grains could provide a basis for more diverse and thriving rural economies. Comparisons with existing perennial crops, e.g. sugarcane or horticulture, may be difficult to learn from because of their very different means of production and market structures.

While perennial grains hold considerable promise for addressing a wide range of ecological and social challenges in the future, the perennial crops, and cultivars themselves are in early stages of development relative to the annual grains and much research in plant breeding and in cropping systems is needed in the decades to come before the ‘utopia’ becomes a ‘real utopia’ (Wright, Reference Wright2010). But a strong momentum exists among plant breeders operating outside of the commercial seed industry around the world, and over 150 research groups on all continents are currently participating in research on perennial grain crops, cropping systems, sociocultural engagement, and supply chain and product development (DeHaan et al., Reference DeHaan, Anderson, Bajgain, Basche, Cattani, Crain, Crews, David, Duchene, Gutknecht, Hayes, Hu, Jungers, Knudsen, Kong, Larson, Lundquist, Luo, Miller and Westerbergh2023). Rapid advances in molecular biology and genetics are facilitating accelerated progress in breeding of perennial crops (Chapman et al., Reference Chapman, Thomsen, Tulloch, Correia, Luo, Najafi, DeHaan, Crews, Olsson, Lundquist, Westerbergh, Pedas, Knudsen and Palmgren2022; DeHaan et al., Reference DeHaan, Larson, López-Marqués, Wenkel, Gao and Palmgren2020; Luo et al., Reference Luo, Najafi, Correia, Trinh, Chapman, Østerberg, Thomsen, Pedas, Larson, Gao, Poland, Knudsen, DeHaan and Palmgren2022; Van Tassel et al., Reference Van Tassel, Tesdell, Schlautman, Rubin, DeHaan, Crews and Streit Krug2020). Perennial rice is already competitive in terms of yield compared with annual rice (Huang et al., Reference Huang, Qin, Zhang, Cai, Wu, Dao, Zhang, Huang, Harnpichitvitaya, Wade and Hu2018; Zhang et al., Reference Zhang, Huang, Zhang, Lv, Wan, Liang, Feng, Dao, Wu, Zhang, Yang, Lian, Huang, Shao, Zhang, Qin, Tao, Crews, Sacks, Wade and Hu2023). For eight breeding cycles of IWG, yield has been increasing by 9% per cycle and is expected to match annual wheat in about 20 years if progress continues with genomic selection as a breeding tool (Bajgain et al., Reference Bajgain, Crain, Cattani, Larson, Altendorf, Anderson, Crews, Hu, Poland, Turner, Westerbergh, DeHaan and Goldman2022) along with other improvements of crop management (Fagnant et al., Reference Fagnant, Duchêne, Celette, David, Bindelle and Dumont2023). Finally, tools and technologies for new crop domestication can be integrated with methods that engage humans, as people are essential for plant domestication processes and cultural valuation and awareness can help drive support for crop development and adoption (Krug et al., Reference Krug, Drummond, Van Tassel and Warschefsky2023; Van Tassel et al., Reference Van Tassel, Tesdell, Schlautman, Rubin, DeHaan, Crews and Streit Krug2020).

Our conclusion is that a perennial revolution would be socially and environmentally desirable, economically viable, and scientifically achievable. However, a perennial revolution will not be achieved overnight but can hopefully be achieved within a timeframe like that of the Green Revolution, about 35 years (Kendall & Pimentel, Reference Kendall and Pimentel1994). Within two to three decades domestication and plant breeding, and other associated fields of research, if sufficiently funded, can probably achieve the necessary increases in yield and other traits that are required for ensuring global food security (DeHaan et al., Reference DeHaan, Anderson, Bajgain, Basche, Cattani, Crain, Crews, David, Duchene, Gutknecht, Hayes, Hu, Jungers, Knudsen, Kong, Larson, Lundquist, Luo, Miller and Westerbergh2023; Krug et al., Reference Krug, Drummond, Van Tassel and Warschefsky2023; Luo et al., Reference Luo, Najafi, Correia, Trinh, Chapman, Østerberg, Thomsen, Pedas, Larson, Gao, Poland, Knudsen, DeHaan and Palmgren2022).

Arguments against a shift to perennial grains based on the need for increasing food production in the next few decades are to some extent valid but should not deter us from looking at the longer term. World agricultural output growth rates are slowing and are now the lowest for at least six decades while the growth rate of Total Factor Productivity has declined in the last two decades (Morgan et al., Reference Morgan, Fuglie and Jelliffe2022). Explanations for the declining growth rates are not fully understood but impacts of climate change and degradation of natural resources are frequently invoked. Our current staple food crops will face unprecedented challenges and perhaps even complete failure towards the second half of this century (Liu et al., Reference Liu, Asseng, Müller, Ewert, Elliott, Lobell, Martre, Ruane, Wallach, Jones, Rosenzweig, Aggarwal, Alderman, Anothai, Basso, Biernath, Cammarano, Challinor, Deryng and Zhu2016; Zhao et al., Reference Zhao, Liu, Piao, Wang, Lobell, Huang, Huang, Yao, Bassu, Ciais, Durand, Elliott, Ewert, Janssens, Li, Lin, Liu, Martre, Müller and Asseng2017). Therefore, the development of completely new crops that are better adapted to the conditions of the Anthropocene should be an urgent priority (Kreitzman et al., Reference Kreitzman, Toensmeier, Chan, Smukler and Ramankutty2020).

4. Obstacles for change

A perennial revolution will challenge politically powerful conventional agriculture supported by economically concentrated agrochemical and seed industries. Inevitably, such radical changes will involve political and economic power struggles, and they are certain to be resisted by existing vested interests. So how can perennial polycultures make inroads into conventional agriculture and ultimately replace annual crops as the mainstay of our food systems? Below we will discuss four broad areas of challenges.

4.1 Interdisciplinary challenges

Competing paradigms are unusual in the core disciplines of the natural sciences, except during short periods of paradigmatic shifts. In many social sciences, however, competing paradigms, or at least perspectives, are the norm and they may persist over generations. In the more applied sciences (e.g. agriculture, energy, environment, and forestry) there are sometimes parallel and competing paradigms, (Persson et al., Reference Persson, Hornborg, Olsson and Thorén2018) each one supported by their vested economic and political interests (MoeSingh, Reference MoeSingh2012). Most obvious is the situation in agricultural sciences where there are two competing paradigms, often called the Productivism Paradigm (Karimi et al., Reference Karimi, Karami, Karami and Keshavarz2021) and the Ecological Paradigm (Kassam & Kassam, Reference Kassam, Kassam, Kassam and Kassam2021). The paradigms differ both in epistemological approaches (Böschen, Reference Böschen2009), and worldviews (Schurman & Munro, Reference Schurman and Munro2010). However, paradigms are not purely epistemic but also part of different, ever competing, food regimes (Friedmann, Reference Friedmann1993; McMichael, Reference McMichael2009). Regimes associated with productivism paradigm are tightly integrated with the food industry, which is one of the most globally consolidated production spheres (Howard, Reference Howard2015). Research and plant breeding within the productivism paradigm is well funded and supported by both state and private sources, while research in the ecological paradigm is substantially less funded and almost exclusively by state funding and philanthropy (Lindner, Reference Lindner2004). In searching for radical change, both paradigms offer necessary insights but neither of them is sufficient (Persson et al., Reference Persson, Hornborg, Olsson and Thorén2018) because neither seriously challenges the very core of agriculture – the overwhelming reliance on annual crops.

For understanding the dynamics of agricultural change, we turn to the concept of a research program by Imre Lakatos, which we believe is more suitable than Kuhn's paradigm (Gholson & Barker, Reference Gholson and Barker1985). Lakatos' view of science differed from that of a paradigm influencing (or even ruling) how science is practiced. Lakatos described the existing scientific knowledge as a hard core of central theses that are irrefutable (or at least highly resistant to refutation), and the core is surrounded by a protective belt of auxiliary hypotheses open for testing (Musgrave & Pigden, Reference Musgrave, Pigden, Zalta and Nodelman2021). An important difference between Lakatos' and our understanding of the world (or agriculture) is that while Lakatos only considered scientific protective belts, we understand the hard core being protected, not only by epistemic protective belts of hypotheses that can be verified or falsified, but protective belts of vested economic and political interests, Figure 2.

Figure 2. Conceptual view of how agricultural sciences can be understood as a research program with a hard core and protective belts of science and vested economic interests, inspired by Lakatos' concept of Research Program (Lakatos, Reference Lakatos1976). A radically different idea, such as domesticating and breeding completely new perennial crops, needs to confront both these protective belts.

In practice this makes change even harder than if the protective belt had been epistemic only. The hard core of agriculture is the annual crops, while the protective belts have multiple dimensions, such as scientific fields (e.g. agronomy, soil science, and plant science), economic (e.g. the agrochemical industrial complex), institutional (e.g. rural advisory services, and industry organizations), ideological (e.g. neoliberalism), and cultural (e.g. beliefs, traditions, and values). A perennial revolution needs to engage with all layers of the protective belts.

4.2 Politics of seeds and agrochemicals

Power over the sources and development of seeds is a key for understanding the evolution of modern agriculture (Kloppenburg, Reference Kloppenburg2005; Mooney, Reference Mooney1983; Peschard & Randeria, Reference Peschard and Randeria2020). From being a public good, often organized as co-operatives, seeds emerged as the linchpin of a commercialization of the agricultural inputs market in the 20th century (Dale, Reference Dale2004; Friedmann, Reference Friedmann1993; Howard, Reference Howard2015; Kloppenburg, Reference Kloppenburg2005). Pivotal moments were the granting of patents on Roundup Ready cultivars in the mid-1990s, and the ruling by the US Supreme Court in 2013, Bowman vs Monsanto (Haugo, Reference Haugo2015; Lim, Reference Lim2013). Against a strong industrial trend of increasing market consolidation and power, there is also a counter movement, seed activism (Peschard & Randeria, Reference Peschard and Randeria2020). Even if seed activism has been around for at least four decades (Mooney, Reference Mooney1983), it has grown stronger recently and is now receiving support from outside of farmers and agricultural activism (Peschard, Reference Peschard2022), to some extent supported by the spectacular legal cases against the agrochemical giant Monsanto/Bayer (Corporate Europe Observatory, 2020; McHenry, Reference McHenry2018). The reason why it is pertinent to talk about a perennial revolution is the profound effect on the seed industry the deployment of perennial crops and cultivars will have. The market for seeds will change dramatically, both in terms of size and in terms of organization, with perennial crops.

Controlling the sources of agricultural seeds has been crucial for achieving dominance of the agricultural inputs market, hence the recent spectacular wave of concentration and control over the seed industry (Bratspies, Reference Bratspies2017; Clapp, Reference Clapp2018, Reference Clapp2021; Dale, Reference Dale2004; Hendrickson et al., Reference Hendrickson, Howard and Constance2017, Reference Hendrickson, Howard, Miller and Constance2020; Kloppenburg, Reference Kloppenburg2005). The agriculture and food sectors are dominated by large firms that sell seeds and agrochemicals, machinery, and data services, and they thrive on the current agricultural model with heavy state subsidies (Bellmann, Reference Bellmann2019; Laborde et al., Reference Laborde, Mamun, Martin, Piñeiro and Vos2021; Lima & Monteiro, Reference Lima and Monteiro2015; Scown et al., Reference Scown, Brady and Nicholas2020). They have significant political power and a strong advantage over pioneers and niche innovations (Bruckner, Reference Bruckner2016; Clapp, Reference Clapp2018; Hendrickson et al., Reference Hendrickson, Howard and Constance2017; Howard, Reference Howard2015). Understanding these dynamics will be crucial for formulating strategies and pathways towards a perennial and more diverse and just agriculture of the future.

In addition to corporate maneuvering of mergers and takeovers, intellectual property rights are an important field for maintaining dominance over the agricultural inputs market. To obtain exclusive rights to a plant variety, it must meet criteria such as being new, distinct, uniform, and stable (Würtenberger, Reference Würtenberger, Matthews and Zech2017). Except for the US, plant varieties cannot be patented but can be protected under plant breeder's rights. However, a genetically modified plant can be protected by a patent. Both the DNA sequence and the organism into which the sequence has been introduced can be subject to patent protection. Therefore, a genetically modified plant may fall under both plant breeder's rights and a patent. Plant breeder's rights are protected for 25 years, while patent protection lasts for a maximum of 20 years in the USA (Le Buanec & Ricroch, Reference Le Buanec and Ricroch2021).

Legal protection of varieties and patents in plant breeding is essential for research and development. However, the fact that seeds can reproduce raises questions about whether it violates plant breeder's rights and/or patent protection when the buyer, typically a farmer, produces the seeds themselves. In contrast to patents, plant varieties protected by plant breeder's rights may be freely used for research and further breeding purposes. Thus, a plant breeding company can utilize a competitor's plant variety in its own crossbreeding efforts. However, with patented seeds, regulations are different. In the case of Bowman v. Monsanto, the United States Supreme Court argued that allowing simple copying as a protected use would undermine the value of patents and reduce innovation incentives (Simmons, Reference Simmons2013).

Considering that commercially cultivated seeds in modern agriculture are often genetically modified and patented, the Bowman case implies that farmers become highly dependent on patent holders, such as Bayer/Monsanto, for their farming operations. Challenging this system, such as saving seeds for future planting, can result in severe economic consequences, as seen in cases like Monsanto vs Scruggs. (Savich, Reference Savich2007).

The rights conferred by patent protection can be used not only to protect one's own inventions, such as GMOs, but also to hinder the development of competing products (Grzegorczyk & Głowiński, Reference Grzegorczyk and Głowiński2020). One conspicuous strategy is acquiring potential rival patents. However, it is also possible to obstruct product development through offensive patent strategies, such as the ‘patent picket fence strategy’ involving pursuing patents closely related to a competing product, thereby complicating matters for the competitor (Brown & Levitt, Reference Brown and Levitt2023). Small organizations with a limited patent portfolio may face challenges in sustaining their existence, as their long-term viability depends on the patents secured by their competitors.

Thus, the development of perennial crops is likely to be significantly delayed if stakeholders who prefer annual crops employ aggressive patent strategies to secure key patents, such as genes that control seed shattering of perennial varieties intended for future commercial use. Various patent strategies employed for commercial purposes can significantly impact innovation and development at the forefront of research. There are numerous examples discussed above that illustrate this effect. These strategies are typically costly, giving larger organizations and companies an advantage over smaller businesses and publicly funded research. This means that individual commercial interests may take precedence over research and development for the greater good. Intellectual property rights and other legislation that can be used (or misused) to acquire and strengthen market power can thus serve as significant protective belts, highlighting the need for international policy actions aimed at enabling innovation for sustainable transitions (Herrero et al., Reference Herrero, Thornton, Mason-D'Croz, Palmer, Benton, Bodirsky, Bogard, Hall, Lee, Nyborg, Pradhan, Bonnett, Bryan, Campbell, Christensen, Clark, Cook, de Boer, Downs and West2020). However, ideas and initiatives to prevent corporate domination over seeds are frequently discussed, the most advanced initiative so far being the Open Seed Initiative (Kloppenburg, Reference Kloppenburg2014; Kotschi & Horneburg, Reference Kotschi and Horneburg2018; Montenegro de Wit, Reference Montenegro de Wit2019).

There has been a strong trend in the concentration of the seed market globally, and not least in the US where only two firms control over 70% of the US corn seed market after mergers in 2012 (Figure 3).

Figure 3. Market share of the US corn seed market. The data for 2018–20 are estimated, and valid for Bayer instead of Monsanto (after the merger in 2018), Corteva instead of DuPont/Pioneer (after the merger in 2018). Source of data (Macdonald et al., Reference Macdonald, Dong and Fuglie2023).

Vested commercial and scientific interests evidently influence the ways in which science is practiced (Druker, Reference Druker2015; McHenry, Reference McHenry2018; Schurman & Munro, Reference Schurman and Munro2010). This can be described and analyzed aptly by Steven Lukes' typology of three dimensions of power (Lukes, Reference Lukes2005; Scherrer, Reference Scherrer, Teipen, Dünhaupt, Herr and Mehl2022). The first dimension, being decision making power (also expressed as ‘power over’ somebody), can be illustrated by several recent and on-going legal processes where market leading companies use their legal power to sue, or threaten to sue, farmers for infringing on patents. The second dimension is called non-decision-making power (also expressed as power to prevent/preempt, or agenda setting). It can be illustrated by the very active role that leading industries take in influencing political agendas about agriculture, e.g. the process of renewal of glyphosate in EU in 2023. The third dimension is called ideological power (also expressed as power to influence people's values, preferences, interests, and perceptions). It can be illustrated by the very active role leading industries take in sponsoring research. A more comprehensive list of examples of Lukes' three dimension is in the supplementary material.

5. Four reasons for optimism

Despite the many obstacles, we offer four reasons for optimism that a perennial revolution of agriculture is imminent in the next couple of decades. In addition to the rapid advance of plant breeding technologies that make perennial grains scientifically achievable, which is a fundamental priority and prerequisite for agricultural change, we understand the four reasons below as positive signals specifically because of their relevance to begin addressing the main political economy barriers.

6. Concluding remark and research priorities

We believe that the time is ripe for the onset of a perennial revolution. The goal of this revolution is the rapid development of entirely new high-yielding perennial grain crops that can replace the current repertoire of annuals. As the diversity of viable perennial pulse, oilseed and cereal crops expands, so will opportunities to experiment with ecologically functional polycultures and other cropping systems thus facilitating the replacement of input intensification with ecological intensification. The result will be cropping systems that preserve the soil, store carbon efficiently, require minimal inputs in terms of commercial energy and machinery, utilize available water effectively, are increasingly self-sufficient in nitrogen and can unlock stores of phosphorous in agricultural soils. Engaging in this endeavor for the benefit of sustainable agriculture will be an exciting research challenge for plant scientists, probably more exciting than incrementally tweaking the existing annual cultivars. It will also foster social science, humanities, and transdisciplinary research on the new sociocultural and economic dynamics of rural societies before, under, and after a perennial revolution. Nevertheless, the revolution is likely to meet strong resistance from the agrochemical industrial complex and societal strategies to address this predicted challenge must be designed.