Despite complex challenges affecting agricultural production that could jeopardize food supply, the Malthusian fears – based on the theory that population growth will outpace agricultural production – have not materialized. This is largely because increases in global food production have consistently kept ahead of global population growth, especially after the industrial revolution.65 The remarkable quadrupling of global agricultural output between 1961 and 2020, achieved with a mere 8 percent expansion in agricultural land,66 represents a significant productivity improvement. Food insecurity today is largely driven by distributional issues affecting access, utilization and stability rather than by global food availability. Historical progress in agricultural productivity growth has been fundamental to food security, poverty reduction and economic development, although patterns have varied considerably across regions.
The evolving, yet fundamental contribution of land
Historically, increases in agricultural output beyond land expansion have relied on two main pathways: increasing inputs (e.g. labour, capital, irrigation, fertilizers, pesticides) per hectare of existing agricultural land; and enhancing the overall efficiency of resource use. The latter pathway is captured by total factor productivity (TFP), which reflects the combined impact of technological advancements, better management practices and more efficient allocation of all inputs, including land. It represents the average productivity of all inputs used to produce all agricultural commodities. Growth in TFP reflects the overall rate of technological advancement and efficiency improvements in the agricultural sector.
As farming systems evolve through innovation, the relative importance of different production factors often shifts. Labour may become less intensive as mechanization increases, or land use might become more efficient with improved crop varieties and management practices. These changes in relative factor shares demonstrate how aggregate TFP growth represents not simply doing more with the same resources, but often transforming how those resources are utilized and combined in the production process, possibly reflecting a change in the mix of commodities produced. Yet, land remains the foundation upon which all agricultural productivity rests, even as its relative contribution to output growth has evolved.
When analysing productivity trends in agriculture, net agricultural area and yield growth provide direct metrics, but improvements in yield depend on complex input interactions. Biophysical inputs such as seed, fertilizers, pesticides and irrigation combine with investments in labour and capital to determine productivity and efficiency. This interplay is essential to understanding the role of land in agriculture. Enhanced yields may stem from input intensification, technological innovation, improved management or combinations thereof. Therefore, yield growth may simply reflect more intensive use of fertilizer, machinery or labour.
As Figure 4 illustrates, net land expansion has played only a minimal role in global output growth. However, the figure masks significant regional variation; indeed, cropland expansion is of particular significance in the Global South.67 While input intensification was the dominant driver in the 1960s, this has gradually given way to TFP improvements as the primary engine of agricultural output growth. The visible decline in the global TFP growth rate since the 2000s has been particularly pronounced in the Global South, including negative TFP growth rates in several African countries. This trend reflects cropland expansion into less productive lands, land degradation, and the impacts of climate change. The importance of reversing this decline in TFP growth has critical implications for food security and natural resource degradation.67 Key factors in achieving this goal include increasing investment in agricultural research and development,68 addressing climate change,69 and improving market infrastructure, trade flows and macroeconomic stability.70
Figure 4 Sources of growth in world agricultural output by decade, 1961–2020
Total factor productivity gains generally raise returns for land, labour and capital, but the most significant gains often accrue to landowners and capital owners. Globally, labour has been increasingly substituted by capital (as the labour force declines), though the average number of workers per farm is very similar across the globe, reflecting capital-intensive and labour-intensive agriculture on large versus small farms, respectively.67 Farm workers may or may not benefit from increased TFP growth, depending on wages and the availability of employment opportunities in other sectors. When these are lacking due to slow rural transformation, multiple factors including small farm size, abundant labour and low TFP growth can combine to create poverty and food security traps.71 Differences in the growth of non-farm sectors and population dynamics, therefore, can create very different patterns of economic growth and inequality.
Yield gaps persist despite past success in yield growth
Global historical trends demonstrate significant yield growth – defined as increase in output per unit of land – driven by both input intensification and TFP growth. Nevertheless, yield gaps persist, threatening the future potential of agriculture. Yield gap is the difference between the maximum attainable yield for a given crop in a specific environment and the actual yields farmers are currently achieving. Even with past successes in yield growth, substantial yield gaps across many regions and crops indicate significant underutilized potential of existing agricultural land. Importantly, these gaps are driven not only by biophysical but also by socioeconomic and institutional constraints. High fertilizer prices, low crop prices, limited access to credit or insurance, and tenure insecurity can disincentivize farmers’ investments in inputs and technologies to close this gap.
The quality and health of agricultural land directly influence the effectiveness of all other inputs and the potential for TFP improvements. As global agriculture faces mounting pressure from land degradation – including soil erosion, salinization, compaction and organic matter loss – the sustainability of productivity gains becomes increasingly precarious. These degradation processes undermine the biophysical capacity of land to support future output growth; if left unaddressed, this could create a troubling feedback loop where productivity declines may prompt further land expansion into fragile ecosystems and remaining forests. The trend observed in Figure 4, indicating a recent increase in land expansion alongside decreasing growth rates of both TFP and agricultural output, serves as an early warning. Policies to reverse this trend and expand the production frontier through innovation may be constrained by biophysical limits in parts of the world with already small yield gaps. Closing existing yield gaps therefore remains critical to maintaining growth in agricultural output supply at historical levels.72
Addressing this challenge requires agricultural policies that recognize land as a complex, living system underpinning the entire agricultural enterprise, coupled with broader environmental stewardship. Future productivity improvements will depend not only on technological innovation and input optimization, but, critically, also on approaches that maintain and enhance fundamental qualities of agricultural land that make all other productivity gains possible. This understanding of the underutilized potential represented by yield gaps, alongside the threats posed by land degradation, provides a critical backdrop for the discussions in subsequent chapters.
