Environmental Performance of Agriculture in OECD Countries

2. Key trends in the environmental performance of agriculture in OECD countries

This section examines key trends in the environmental performance of agriculture across OECD countries, based on data from the 2025 version of the OECD dashboard Measuring the Environmental Performance of Agriculture. The dashboard presents the evolution of key indicators in the Agri-Environmental Indicators (AEI) database for the OECD as a whole and in each country it covers.

Increased total agricultural production in OECD countries (+40% overall between 1990 and 20211) has been accompanied by progress in the sector’s environmental performance over the observation period, for example improvements in both emissions intensity and nutrient use efficiency, signalling a relative decoupling of environmental effects of production. However, the data presented in this report suggest that such gains were generally concentrated in the first two decades of the observation period, and improvements in environmental performance since 2010 were more difficult to achieve.

Natural resource and other input uses

Between 2009-11 and 2019-21, there were mixed trends in the use of key agricultural inputs in OECD countries. While direct on-farm energy consumption remained relatively stable, with a low annual increase (0.4% for the OECD), the use of nitrogen and phosphorus fertilisers grew at higher rates, with phosphorus use increasing the most (1.7% per year). Water abstraction also increased (1.0% per year), indicating rising pressures on water resources across OECD countries (Figure 2.1).

While trends in agricultural input use reflect shifts in production practices across OECD countries, changes in land use patterns provide further insight into how agricultural landscapes are evolving over time. Total agricultural land area in OECD countries, which decreased by 10% since the 1990s, remained relatively stable between 2011 and 2021, with a negligible annual increase of 0.02% (Figure 2.2). However, land use patterns within the sector shifted significantly. Cropland area declined at an average annual rate of 0.7%, while pasture area expanded by 0.4% per year. These changes suggest a shift in land use dynamics, potentially reflecting factors such as land conversion, changes in agricultural production systems, and policies aimed at preserving or restoring natural ecosystems. Combined with the observed increased use of agricultural inputs, this suggests an overall slight intensification of cropland production in OECD countries.

Environmental impacts

Nutrient balances

Some environmental effects of agriculture stem from the status of input management and efficiency. While nutrients inputs can contribute to soil fertility when applied in the right quantities, persistent nutrient surpluses could indicate inefficiencies and environmental risks, e.g. acidification of soils and eutrophication in water bodies. Figure 2.3 illustrates the evolution of nitrogen and phosphorus balances (kg per hectare) in OECD countries since 1990.

From 1990 to 2009, the nitrogen balance (Panel A) shows a marked decline in the maximum value observed across OECD countries, which is representative of observed improvements in nutrient management or reduced fertiliser use across OECD countries with the highest nutrient balances. However, since 2010, the OECD maximum value for nitrogen balance has shown an increasing trend, reflecting an observed resurgence of nutrient surpluses across highest-emitting OECD countries. Meanwhile, the median values remained relatively stable since 1991 and the minimum values hovered close to zero with a deficit observed in a country in 2020, perhaps associated with input constraints during the first year of the COVID-19 pandemic.

The phosphorus balance (Panel B) follows similar trends, with less pronounced changes. The maximum value follows a mostly downward trend until early 2010s, but progress has stalled over the past decade. The median values remained relatively stable, although on a relatively lowering trend close to zero. Meanwhile, the minimum values show that one or more countries have been facing deficit in phosphorus since 2004, with a small decrease again in 2020.

These observed trends in nitrogen and phosphorus surpluses across OECD countries reflect shifts in fertiliser use and environmental pressures, highlighting ongoing efforts to improve nutrient use efficiency in agriculture. Optimising nutrient use is an important lever to improving agricultural sustainability, yet there remains significant margin for improvement (Figure 2.4). Higher efficiency levels indicate better nutrient management which reduces environmental impacts, while lower values highlight persistent challenges to minimise nutrient losses.

Nitrogen use efficiency, measured as the ratio of outputs to inputs, has shown slight improvements over time, though fluctuations persist. The median efficiency has reached 0.6 in recent years, meaning however that only about 60% of applied nitrogen is effectively converted into outputs. This suggests ongoing challenges in reducing nutrient losses and optimising fertiliser use with 40% lost to the environment through soil, water or air. Phosphorus use efficiency has exhibited a clearer upward trend since the early 2000s, reflecting improved nutrient management overall.

These trends underscore the progress achieved in nutrient use efficiency, while emphasising the need for further improvements to reduce nutrient losses and their environmental impact.

GHG and ammonia emissions

Agriculture remains a significant GHG-emitting sector through its methane and nitrous oxide emissions. Figure 2.5 illustrates the trends in GHG emissions from agriculture in OECD countries. Since 1990, methane emissions in OECD countries have fluctuated around 850–900 million tonnes CO₂-equivalent, with a slight decreasing trend until the mid-2010s, exhibiting however a rebound since then, to stabilise at a level slightly exceeding their historical values. In contrast, nitrous oxide emissions make up a relatively smaller proportion of total GHG emissions from agriculture but show greater variability, particularly with a noticeable rise between 2012 and 2018, followed by a decrease in the recent years.

These trends reflect the ongoing influence of livestock production and fertiliser use on agricultural GHG emissions, with methane primarily linked to enteric fermentation and manure management, while nitrous oxide emissions being largely driven by nitrogen-based fertilisers and associated soil processes. While agriculture also generates CO₂ emissions, these are comparatively much smaller and result mainly from soil processes. Overall, GHG emissions have increased from 1 453 million tonnes of CO₂ equivalent in 2009-11 to 1 515 million tonnes (+4.3%) in 2019-21, which corresponds to an average annual growth rate of 0.4% over the period.

One way to reduce GHG emissions is to limit emission intensity of agricultural products. Figure 2.6 illustrates the evolution of GHG emissions intensity across OECD countries from 1990 to 2021, measured in kilograms of CO₂ equivalent per unit of agricultural output (USD). Over this period, the OECD maximum emissions intensity steadily declined, decreasing from above 4 kg CO₂e/USD in 1990 to less than 3 kg CO₂e/USD since 2014, reflecting improvements in productivity and adoption of less GHG-emission intensive practices. The OECD median has also declined by approximately 12%, from around 1.5 kg CO₂e/USD in the early 1990s to 1.3 kg CO₂e/USD in 2021. However, the rate of decline has slowed down over the recent period, from -0.6% per year in the 1990s and 2000s to -0.2% per year since 2010. The OECD minimum, in comparison, has remained consistently low.

Despite these improvements in emissions intensity, total emissions from the sector have continued to rise. This suggests a situation of relative decoupling, where emissions grow at a slower rate than output. However, achieving absolute decoupling — a reduction in total emissions — would require more transformative changes, as efficiency gains alone have not been sufficient so far to compensate for the growth of agricultural production.

Manure from livestock production and fertiliser use can also generate ammonia emissions contributing to air and water pollution. Agricultural ammonia emissions across OECD countries declined moderately from 2001 with slight fluctuations until the mid-2010s. As from 2015, the trend on emissions began to reverse with an average annual growth rate of 2.8%, leading to a record high level in 2021 over the last two decades (Figure 2.7). This could be the source of potential environmental threats in the most affected regions.

Farmland biodiversity

The impact of agriculture on biodiversity also remains an important challenge, as observed with farmland bird populations serving as an important indicator of ecosystem health in a subset of OECD countries.

Figure 2.8 illustrates the evolution of the farmland birds index across OECD countries. Of the 27 countries within OECD countries reporting that indicator, 22 experienced a decline in farmland bird populations between 2009-11 and 2019-21, signaling ongoing pressures from agricultural intensification, habitat loss, or land use changes. In contrast, only five countries reported a positive trend, suggesting localised improvements in conservation efforts or habitat management. The overall pattern underscores the continued challenges in maintaining farmland biodiversity and the need for targeted agri-environmental policies to support bird populations. More effort is ongoing to complement this indicator, including in non-covered countries, with the monitoring of farmland habitat biodiversity.

The overall environmental performance of agriculture in OECD countries is a mix of progress and persistent challenges. While improvements in nutrient use efficiency and emissions intensity indicate advances in sustainable practices, higher overall GHG emissions, nutrient surpluses, and worsening biodiversity indicators in some countries remain pressing concerns. Trends in land use, input consumption, and air emissions highlight the complex interplay between agricultural production and environmental sustainability. The continued decline of farmland bird populations further underscores the need for targeted policies to mitigate biodiversity loss. Strengthening data-driven policy approaches will be essential to improve sustainable productivity growth, ensuring that future food systems are both resilient and sustainable.

Note

← 1.  See OECD/FAO (2024), OECD-FAO Agricultural Outlook 2024-2033, OECD Publishing, Paris/FAO, Rome, https://doi.org/10.1787/4c5d2cfb-en.