By Rattan Lal
2020 World Food Prize Laureate
CFAES Rattan Lal Carbon Management and Sequestration Center
The Ohio State University
http://cmasc.osu.edu

Author Note:
Rattan Lal https://orcid.org/0000-0002-9016-2972
Rattan Lal has no conflicts of interest to disclose.
Correspondence concerning this article should be addressed to:
Rattan Lal, 210 Kottman Hall, 2021 Coffey Road, Columbus, OH 43210 USA
Email: [email protected]

ABSTRACT

The Green Revolution (GR) of the 1960s doubled the world’s average cereal yield. It saved hundreds of millions from starvation through the timely intervention of growing high-yielding crop varieties with inputs of agrochemicals and irrigation. Over six decades, the GR is also often linked with soil degradation, contamination and overdraw of water, pollution of air, emission of greenhouse gases into the atmosphere, and loss of biodiversity. While the quantity of food produced was increased, its nutritional quality decreased, with adverse effects on human health. With the projected increase in world population from 7.8 B in 2021 to about 9.8 B by 2050, food demand is projected to increase by 60 percent, which supposedly may need additional land and water resources. In this context, the GR of the 21st century must be soil-centric, based on restoration of soil health and its resilience, ecosystem-oriented, based on an increase in ecoefficiency and less dependence on external inputs, and science-based, using proven scientific knowledge, which produces enough food from less land, water, and other external inputs. The strategy is to protect, restore, manage, and return some land to nature without horizontal agroecosystems. Rather than a problem, restoration and sustainable soil health management will make agriculture a solution to environmental issues. It is essential to reconcile the need for meeting the food demand with the necessity of improving the environment by restoring soil health. Good soil health equals good and nutritious food, good human health, and good environmental quality.

INTRODUCTION

Ensuring food security has challenged humanity throughout recorded history. Whether the rate of food production can exceed that of population growth pre-dates the Malthusian era. These concerns have challenged humanity and necessitated innovations in agriculture, of which the most prominent is the so-called “Green Revolution” (GR) of the 1960s, which enormously boosted agronomic productivity. The GR was based on growing high-yielding crop varieties and using chemical fertilizers and pesticides, irrigation, and other fossil-energybased inputs for soil tillage and other farm operations. (Lawrence, 2019) While the population is increasing at about 100 million per year, and it is expected to reach 9.8 B by 2050 (U.N., 2019), cropland area has peaked at about 1.5 B ha since the early 2000s. (FAO, 2020; Thenkabail, 2010) Because of the GR, global cereal yields have more than doubled from 1.5 Mg/ha in the 1960s to 3.2 Mg/ha in 2018. (Chávez-Dulanto et al., 2021) Per capita, world food production has increased by 24 percent to 40 percent through the adoption of GR technologies. (Shanka, 2020) However, there is no cause for complacency. Many argue the need for a further doubling of cereal yield by 2050 under the growing risks of a warming climate, degrading soils, dwindling biodiversity, increasing water scarcity, and growing plant parasites and pathogens risks.

It is also argued that the historic GR was not green enough (Harvey, 2009) because of the severe problems of soil degradation affecting 1.9 B ha or 30 percent of the land area. (IPBES, 2019) Thus, there has been a call for a greener revolution. (Kesavan & Swaminathan, 2008) Further, large amounts of grains are fed to cattle, and one-third or 1.3 Gt of food is wasted on a global scale. (FAO et al., 2019) For 1.7 B small landholders and resourcepoor farmers, 70 percent of which are women, the GR prescription has been considered a bitter pill (Vercillo et al., 2020) because of the growing dependence on chemical fertilizers, pesticides, and other inputs with adverse impacts on the environment and increasingly worsening soil health of agroecosystems. These inputs also aggravate emissions of greenhouse gases (GHGs) and accelerate anthropogenic global warming. A study in Pakistan showed that a one percent increase in area irrigated, agricultural tractors, and fertilizer application increases CO2 emissions by 0.35, 0.33, and 0.32 percent, respectively. (Arif & Dilawar, 2020)

Therefore, the objective of this essay is to deliberate agricultural innovations that reconcile the need to produce an adequate quantity of nutritious food for the growing and increasingly affluent human population with the absolute necessity of restoring degraded soils, improving the quality and renewability of water, increasing above and below ground biodiversity, and adapting to and mitigating anthropogenic global warming. Rather than a problem, the strategy is to make agriculture a solution to addressing environmental degradation.

ECO-FRIENDLY AGRICULTURE

Science-based and innovative agriculture has a bright future ahead. So-called eco-friendly agriculture must address environmental issues (i.e., soil functionality, climate change, water quality, biodiversity) while producing enough and nutrient-dense food for the growing population. Indeed, more changes in food production and consumption systems will occur between 2020 and 2050 than have happened since the onset of settled agriculture about ten millennia ago. Therefore, GR of the 21st century must be: i) soil-centric, based on soil health and resilience, ii) ecosystem-centric, based on eco-efficiency of inputs, iii) knowledge or innovation-centric, based on scientific principles, and iv) nature-centric, based on nature positive solutions which restore and enhance nature.

The new GR must also recognize the “One Health” concept, which states that the “health of soil, plants, animals, people, ecosystems, and the planetary processes is one and indivisible.” (Lal, 2019a, 2019c) The soil-food security-human health nexus must be recognized and strengthened. (Oliver & Gregory, 2015) Therefore, food production systems must address environmental and resource management issues. Human health, a fingerprint of soil health (Brevik et al., 2020), must be improved by adopting innovative options which restore and sustain the health of degraded, polluted, contaminated, depleted, and desertified soils. The strategy is to connect food and people (Ball et al., 2018) and soil and people (Poch et al., 2020) because these connections have been lost and must be reestablished. Basic concepts of innovative agricultural practices outlined in Figure 1 emphasize the One Health concept, the importance of soil and environmental protection and restoration, nature-positive approaches, and reduced dependence on external inputs.

TECHNOLOGIES FOR IMPROVING SOIL HEALTH AND INCREASING GLOBAL AGRICULTURAL PRODUCTIVITY

About 2 billion people are malnourished because of the deficiency of micronutrients, protein, and vitamins. The COVID Pandemic has rendered an additional 160 M food-insecure through December 2020. Soil degradation is among the principal causes of human malnutrition. (Lal, 2009) Higher concentrations of atmospheric CO2, which has increased drastically since the 1950s, enhance biomass production but decrease wheat, rice, and other C-3 plants. (Ebi et al., 2021) There is also strong evidence of widespread micronutrient deficiencies (e.g., Zn, Cu, B, Fe, Mo) in the cropland soils of Sub-Saharan Africa (Kihara et al., 2020) and elsewhere in developing countries. Kihara et al. (2020) observed that micronutrient fertilization (agronomic biofortification) increases micronutrient concentration in edible plant components.

Examples of innovative options, in accord with basic concepts outlined in Figure 1, are listed in Table 1. These technologies, specifically designed to reduce conflict between humans and nature (Lal, 2019b), are climatefriendly, pro-nature, and soil restorative and regenerative. To be fine-tuned for site-specific conditions, these practices enhance soil health, increase the ecoefficiency of inputs, sustain agronomic productivity, and improve the nutritional contents of food. Adopted on a landscape basis, following a holistic approach, these practices would reduce agrochemical dependence and impart disease-suppressive characteristics to the soil.

Major issues that need to be addressed through scientific innovations are soil degradation (i.e., accelerated erosion, depletion of soil organic matter (SOM), decline of soil structure, nutrient imbalance and decline, salinization, acidification, contamination, and plastic pollution); excessive/indiscriminate use of agrochemicals and other inputs based on fossil fuels; relentless expansion of agriculture, leading to conversion of natural to managed ecosystems; and plastic pollution and lead contamination in croplands, which have become significant threats to long-term food security in China (X. Zhang et al., 2020; Y. Zhang et al., 2019) and elsewhere. Soil, finite and fragile and teeming with life, is taken for granted and made prone to climate change and other anthropogenic perturbations. One-third of global soils are already affected by moderate to severe degradation by diverse processes. (Rojas et al., 2016)

In this context, the focus should be on regenerative practices (Lal, 2020a) that restore soil health, enhance SOM content, improve soil structure, strengthen activity and species diversity of soil biota, and reinforce the food-energy-water-soil (FEWS) nexus. (Lal, 2014b, 2015a; Lal et al., 2017; Mabhaudhi et al., 2016) The FEWS nexus is strengthened through the restoration of SOM content by adopting strategies of integrated soil fertility management or ISFM (Imran, Amanullah, & Al-Tawaha, 2021; Imran, Amanullah, Hussain, et al., 2021; Voltr et al., 2021) such as recycling of biomass-C and use of various organic amendments. The nexus also highlights the dictum that “good soil = good food = good human health.” (Outwater, 2001) This concept must be taught at all levels of education, beginning with elementary school. The COVID pandemic has also amply demonstrated the necessity of strengthening local food production systems. In this context, the importance of urban farming and soil-less agriculture (i.e., aquaponics, hydroponics, aeroponics) can never be over-emphasized. (Lal, 2020; Lal et al., 2020)

Conservation agriculture (CA) is practiced on some 180 Mha of global cropland. (Kassam et al., 2019) The effectiveness of CA can be significantly enhanced if used in combination with cover cropping (Eash et al., 2021; Haider et al., 2019), retention of crop residue mulch (Noor et al., 2021; Salahin et al., 2021), and complex crop rotations. Nunes et al. (2018) documented that no-till (CA) performance in temperate regions is enhanced by integrating other practices such as cover cropping and crop rotations. Nunes and colleagues observed that the benefits of introducing grass or legume cover crop mixtures into the cropping system are evident after four years for SOM content, plant-available water capacity, and Fe and Zn contents and that effects of cover cropping were greater under CA than with conventional tillage. Furthermore, better soil quality under CA results in higher agronomic yields in loamy sand and silt loam soils, but not in clayey soils. (Nunes et al., 2018)

Rather than bringing new land under agriculture, as proposed by some (Lal, 2021; Ranganathan et al., 2018), the prudent strategy is to protect, restore, manage, and return some land to nature. (Lal, 2021) The global land area under agriculture of 5 B ha (1.5 B ha under cropland and 3.5 B ha under grazing land/pasture) is far more than needed to adequately feed the current and projected population and generate other ecosystem services. With proven scientific technologies (Table 1), Prudent management can double agronomic production in developing countries, narrow the yield gap, and facilitate the return of some land (e.g., marginal to agricultural use) to nature. The set-aside land will also be a major sink of atmospheric CO2 by sequestration of carbon in soil and vegetation. Furthermore, widespread adoption of improved and scientifically proven practices will make agriculture a solution to mitigating global warming and improving the environment.

Widespread adoption of improved technologies can be facilitated by identifying and implementing policies at local, regional, national, and global scales. There is a strong need for a soil protection and restoration act. In the U.S., for example, there is a Clean Water Act, Clean Air Act, but there is no Soil Health Act. In addition to nature-positive legislation, farmers must also be incentivized to adopt recommended management practices through payments for ecosystem services. Funds allocated for subsidies (e.g., for irrigation, nitrogen fertilizer) can be re-appropriated towards payments for ecosystem services such as sequestering carbon in soil and trees, improving renewability and quality of natural waters, and strengthening the above and below-ground biodiversity. Payments to farmers, such as sequestration of carbon, must be based on societal value (Lal, 2014a) just, fair, and transparently. Undervaluing a precious resource (i.e., such as SOM) can lead to a tragedy of the commons. Furthermore, soil carbon credits need clear standards for assessment and upscaling to farm level.

CONCLUSIONS

The Green Revolution of the 1960s, an important and timely innovation, saved humanity by providing food to hundreds of millions prone to undernutrition and malnutrition and saved the world from widespread risks of civil strife and political unrest caused by desperation and suffering. The adverse effects on the environment, caused by excessive/indiscriminate use of chemicals and in-field burning or removal of crop residues and monocropping of cereals grown with excessive plowing and flood-based irrigation, must be addressed the adoption of scientifically proven practices. Paramount among these is conservation agriculture practiced in combination with cover cropping and residue retention as mulch along with complex rotation and integrated soil fertility management. This is an example of regenerative agriculture that restores SOM content, enhances soil health, and makes agriculture a solution by adapting to and mitigating anthropogenic climate change and restoring the environment (soil, water, air, biodiversity). The soil of good heath produces food of good nutritional quality and leads to good human health because good food is good medicine. Adopting improved agricultural practices will narrow the yield gap and enable the return of some agriculturally marginal lands to nature. Urban agriculture and soil-less food production systems can promote vertical/sky-farming and strengthen local food production systems. Indeed, agriculture and world food systems are set for a major paradigm shift and drastic transformation to nature/soil-centric solutions.