In recent years, the debate surrounding organic agriculture and its environmental impacts has intensified significantly. While agroecology has gained substantial popularity among consumers seeking sustainable food options, the scientific consensus regarding its benefits compared to conventional farming methods has remained somewhat divided. A groundbreaking new study (Sanders et al., 2025) published in the journal ‘Organic Agriculture’ provides what may be the most comprehensive assessment to date of organic farming’s benefits for both environmental protection and animal welfare.
The largest comparative study of its kind
The recently published research paper, ‘Benefits of organic agriculture for environment and animal welfare in temperate climates’ by Sanders et al. (2025), represents the most extensive evaluation of organic versus conventional farming systems conducted thus far. What makes this study particularly noteworthy is its unprecedented scope:
‘So far, this study is the largest one of its kind and the first one that adds the aspect of animal welfare to a comprehensive array of impact categories‘ (Sanders et al., 2025, p. 1).
The international research team, comprising 19 researchers from prestigious agricultural research institutions across Europe, conducted a systematic review of scientific literature spanning three decades (1990-2018). Their analysis encompassed 463 studies featuring 2,141 pairwise comparisons between organic and conventional farming systems, all conducted in temperate climate zones.
Methodology: a systematic approach
The researchers implemented a rigorous methodology to ensure comprehensive and reliable results. Their approach involved:
- systematic literature search. The team searched multiple scientific databases including Web of Science, Scopus and Organic Eprints, supplemented by web-based searches to identify relevant studies;
- clear selection criteria. Only studies from temperate climate zones that contained pairwise comparisons between organic and conventional farming systems were included. Organic systems needed to have been managed organically for at least two years prior to data collection;
- data extraction and standardisation. Relevant data were extracted from publications and converted to standard units where necessary. When data were presented graphically, the researchers used WebPlotDigitizer for standardised extraction;
- categorisation of results. Each pairwise comparison was categorised based on whether organic farming provided clearly more, similar, or fewer benefits than conventional agriculture. Where significance levels were provided in original publications, these were used for categorisation; otherwise, threshold values (typically ±20%, with lower thresholds for indicators with smaller variations) determined whether differences were classified as ‘clear’.
Key findings: environmental benefits confirmed
The study’s findings confirm substantial environmental advantages of organic farming across multiple domains:
Water protection: safeguarding a vital resource
Water quality protection emerged as one of the strongest advantages of organic farming systems. The comprehensive analysis examined multiple aspects of water protection, with particular focus on nitrate leaching and pesticide contamination — two of the most significant agricultural impacts on water resources.
Nitrate leaching
In 175 of 386 comparisons (45%), organic farming led to significantly lower nitrate leaching, while conventional farming performed better in only 73 cases (19%). On average, organic methods reduced nitrate leaching by 26% compared to conventional practices. The remaining 138 cases (36%) showed no clear difference between the systems.
The researchers noted important context-dependent variations in these results. The most substantial reductions in nitrate leaching under organic management occurred in arable cropping systems, particularly those with diverse crop rotations incorporating legumes at appropriate proportions. As the authors explain:
‘Comparatively high N-losses of organic farming were usually a result of a very high plough-in rate of legumes or a high share of intercrops under conventional systems – both not being representative for organic and conventional systems‘ (Sanders et al., 2025, p. 5).
This highlights the importance of timing and management in nitrogen utilisation within organic systems. When green manures or cover crops were incorporated at appropriate times relative to subsequent crop needs, nitrate leaching was minimised. Conversely, when large amounts of nitrogen-rich plant material were incorporated without synchronising with crop demands, leaching losses increased.
The study also revealed that organic systems performed particularly well in vulnerable areas such as water protection zones and regions with sandy soils prone to leaching. This suggests that organic farming could serve as a targeted solution in environmentally sensitive areas where water quality protection is a priority.
Pesticide contamination
The findings regarding pesticide impacts on water quality were even more definitive:
‘In 57 of 62 comparison pairs (92%), the potential or proven risk to groundwater and surface water from the use of plant protection products is lower in the organic compared to the conventional variant‘ (Sanders et al., 2025, p. 5).
Only in three comparison pairs from a single study did conventional farming show better results for pesticide impacts, which the researchers attributed to drift contamination from neighbouring conventional farms.
The authors note that the clear advantage of organic farming for pesticide-related water protection stems directly from the prohibition of synthetic chemical pesticides in organic standards. While organic farming does permit certain natural substances for pest control, these typically have lower environmental persistence, reduced leaching potential, and lower overall toxicity profiles compared to many synthetic alternatives (Burtscher-Schaden et al., 2022).
An additional finding worth noting is that organic farms often maintained more extensive buffer zones along waterways, further reducing the risk of agricultural runoff reaching water bodies. This practice, combined with the reduced use of soluble fertilisers, created multiple barriers protecting water resources.
Additional water quality parameters
Although not extensively studied in the reviewed literature, the researchers also found indications that organic farming could reduce phosphorus contamination of water bodies, primarily due to lower soil erosion rates (discussed in the soil conservation section). This is particularly significant as phosphorus runoff is a major contributor to eutrophication of freshwater systems.
Soil conservation: building fertility and resilience
The positive effects of organic farming on soil conservation were demonstrated across biological, chemical, and physical indicators. In 236 of 359 comparisons (53%), organic farming led to better soil conservation, while the opposite was found in only 62 pairs (17%). The remaining 30% showed no clear difference. This multi-faceted analysis provides a comprehensive picture of how organic management affects soil health.
Soil biological activity
The most dramatic benefits were observed in soil biological indicators, particularly earthworm populations:
‘From 64 comparisons, the abundance was higher in 57 cases under organic management. On average, it was 78% higher‘ (Sanders et al., 2025, p. 7).
The researchers identified several factors contributing to this enhanced biological activity, including:
- higher quantities and diversity of organic inputs (compost, manure, green manures);
- absence of synthetic chemical pesticides that can harm soil organisms;
- more diverse crop rotations supporting varied soil habitat conditions;
- lower overall disturbance regimes in many organic systems.
Beyond earthworms, the study found enhanced microbial biomass and activity in organic soils, though these parameters were examined in fewer studies. Soil enzyme activities, which serve as indicators of biological function, were typically higher in organic systems, suggesting more active nutrient cycling processes.
The researchers emphasise the ecological significance of these findings:
‘A diverse, species-rich and abundant earthworm population on a site indicates a fertile and biologically active soil with intact soil structure and good water infiltration capacity‘ (Sanders et al., 2025, p. 7).
This biological foundation underpins many of the other soil health benefits observed in the study.
Soil chemical properties
Regarding soil chemical parameters, the picture was more nuanced. Plant-available phosphorus was higher in organic systems in 15 of 35 pair comparisons (43%), while soil pH was higher in 48 of 71 comparisons (68%). On average, phosphorus content and pH value were 5% and 3% higher, respectively, under organic management.
The researchers note that these modest but positive differences reflect the different nutrient management approaches in organic systems:
- greater reliance on organic materials that release nutrients gradually;
- use of rock phosphate and other mineral amendments that slowly increase nutrient availability;
- management practices that enhance mycorrhizal associations and other soil biological processes that improve nutrient access.
The study also found that organic soils typically had higher cation exchange capacity and organic matter content, both of which contribute to nutrient retention and long-term soil fertility. While many conventional systems can maintain adequate nutrient levels through synthetic fertiliser applications, the organic systems demonstrated greater inherent fertility and nutrient-holding capacity.
Soil physical structure
The analysis of soil physical properties revealed significant benefits of organic management for soil structure and function:
‘Organic farming practices lead to a higher infiltration rate (in 16 of 19 comparison pairs, on average +137%) and a higher aggregate stability (in 28 of 40 comparison pairs, on average +15%)‘ (Sanders et al., 2025, p. 7).
These improved physical properties translate directly into enhanced water management capacity, with organic soils typically demonstrating:
- greater water infiltration, reducing runoff during heavy rainfall events;
- enhanced water retention during dry periods;
- better aeration and reduced compaction, supporting root growth and biological activity.
Bulk density measurements showed mixed but generally positive results, with lower (better) values in 8 of 18 comparisons and similar values in another 8 comparisons. Similarly, penetration resistance was lower (better) in 28 of 58 comparisons and similar in another 28 comparisons.
Soil erosion protection
Perhaps most significantly from a long-term sustainability perspective, organic farming demonstrated clear benefits for reducing soil erosion:
‘The surface runoff was lower in 12 of 17 comparisons (on average −22%). A similar result was shown for soil loss. From 37 comparison pairs, clearly lower loss values were found in 24 pairs (on average, −26%)‘ (Sanders et al., 2025, p. 7).
The researchers attribute these erosion-protection benefits to several factors characteristic of organic farming systems:
‘The advantages of organic farming identified in the analysis can be explained by the crop rotation in organic systems with a significant share of grass-clover leys, by higher soil cover and the high relevance of soil protection in the organic VG v. V farming‘ (Sanders et al., 2025, p. 7).
The study notes, however, that these benefits were diminished when comparing organic systems using conventional tillage to conventional systems using reduced tillage or no-till practices:
‘On the other hand, soil conservation was often worse when organic variants with conventional tillage (i.e. ploughing) were compared to conventional variants with reduced tillage or no-till systems‘ (Sanders et al., 2025, p. 7).
This observation highlights a potential area for improvement in organic systems, the development and wider adoption of reduced tillage methods adapted to organic conditions.
Biodiversity enhancement: supporting ecosystem complexity
The researchers’ analysis of biodiversity impacts revealed some of the most significant advantages of organic farming. The comprehensive evaluation examined both flora and fauna diversity across various agricultural settings, with consistently positive outcomes for organic management.
Flora diversity and sbundance
For flora richness, the evaluation of 105 comparative pairs showed remarkable benefits under organic management:
‘89 pairs had a higher number of species in favour of the organic variant (arable flora: 69 comparisons, arable seedbank: 10 comparisons, field margin vegetation: 10 comparisons)‘ (Sanders et al., 2025, p. 7).
Only in one pair of comparisons on arable flora, where the conventional system was managed very extensively, did organic management show lower species richness. The magnitude of these differences was substantial:
‘On average, species richness of arable flora was 95% higher under organic management. Inside the fields, the median even reached 304%‘ (Sanders et al., 2025, p. 7).
The seedbank – representing the reservoir of dormant seeds in the soil – also showed significant benefits under organic management, with 61% higher species richness on average. Field margin vegetation demonstrated a more modest but still meaningful increase of 21% in species richness.
Flora abundance showed similarly positive results, with higher plant numbers under organic management in all 15 pairs compared. This included 7 comparisons for arable flora, 6 for seedbank, and 2 for field margin vegetation.
Fauna diversity and abundance
The benefits for wildlife were also substantial, in organic agriculture, though slightly less dramatic than for plant diversity. The evaluation of 53 comparative pairs on fauna richness showed that:
‘The number of species in the organic variants was higher in 26 comparison pairs (birds: n=11 comparisons, insects: n=15 comparisons), while negative effects occurred for neither fauna groups’ (Sanders et al., 2025, p. 8).
Taking all comparison pairs into account, bird species diversity was 35% higher on organic farms, while flower-visiting insects (such as bees, hoverflies, and butterflies) showed 23% greater species richness.
For fauna abundance, 41 of 92 pairs had higher values under organic farming, while 11 pairs from a single study showed negative effects. On average, fauna abundance was 23% higher for birds and 26% higher for insects under organic management.
The researchers also noted important spatial variations in these biodiversity benefits. For birds, the differences were most pronounced at the farm level rather than the field level, reflecting the importance of habitat complexity and landscape features. For insects, particularly pollinators, benefits were observed at both field and farm scales, with the greatest differences occurring in simplified landscapes where organic farms provided rare habitat resources.
Mechanisms of biodiversity enhancement
The researchers identified several key mechanisms through which organic farming supports biodiversity:
- reduced pesticide use. The prohibition of synthetic chemical pesticides eliminates direct toxic effects on non-target organisms and preserves food webs;
- lower nitrogen inputs. Reduced fertility creates less dense crop canopies, allowing light penetration and supporting understory plant communities;
- diverse crop rotations. The inclusion of multiple crop types, including legumes and temporary grasslands, provides varied habitat and food resources throughout the year;
- habitat features. Organic farms often maintain more uncultivated areas, field margins, and landscape elements that support wildlife;
- timing of operations. Differences in the timing of field operations (such as later or staggered harvesting) can benefit species at critical life stages.
As the researchers explain:
‘Differences between the management systems can mainly be explained by the fact that no chemical herbicides are applied in organic farming. Furthermore, no synthetic nitrogen fertilisers are used and the overall lower nutrient level results in a lower crop density and thus better living conditions for less competitive species‘ (Sanders et al., 2025, p. 7).
Landscape context
An important finding from the biodiversity assessment was the influence of landscape context on the magnitude of organic farming benefits:
‘It is worth mentioning that landscape structures also have a significant impact on biodiversity, especially on fauna. Many species of birds and insects use cultivated land only occasionally as a part of their habitat and depend greatly on the number and quality of landscape elements‘ (Sanders et al., 2025, p. 8).
The study found that the biodiversity benefits of organic farming were generally largest in simplified, homogeneous landscapes where organic farms provided rare habitat resources. In complex landscapes with abundant semi-natural habitats, the relative advantage of organic farming was sometimes reduced, though still positive.
This finding has important implications for targeting conversion to organic farming in regions where it might deliver the greatest biodiversity benefits.
Climate protection
The comparison of empirical results for soil-derived greenhouse gas emissions from organic and conventional agriculture revealed positive effects from organic management. One of the main reasons for this advantage is the ability of organic farming to store carbon in soils through the cultivation of legumes and the use of organic fertilisers.
In total, in 134 of 270 pairwise comparisons (50%), soil organic carbon content was higher in the organic variant, while there were no differences in 89 pairs (33%) and 47 pairs (17%) had a lower carbon content compared to the conventional variant. On average across all pairwise comparisons, organic carbon content was 10% higher under organic management.
The advantage was even more pronounced regarding carbon sequestration rates:
‘32 of 41 pairs indicate more frequent use of intercrops leads to a higher carbon sequestration. Taking all pair comparisons into account, the annual carbon sequestration rate was on average also higher in the organically managed soils (275 kg ha-1 compared with 40 kg ha-1 in conventionally managed soils)‘ (Sanders et al., 2025, p. 10).
For nitrous oxide (N₂O), a potent greenhouse gas, emissions were lower in organic systems in 20 of 35 pairwise comparisons (57%). On average, emissions were 24% lower according to the studies evaluated.
Using standard CO₂ equivalence values, the researchers calculated that:
‘The cumulative greenhouse gas reduction of organic farming was 1,082 kg CO₂e per hectare and year‘ (Sanders et al., 2025, p. 11).
This significant climate protection benefit stems from multiple aspects of organic management, including enhanced soil carbon sequestration, reduced synthetic input use (particularly nitrogen fertilisers), and more diverse cropping systems.
Resource-use efficiency
The study found that organic farming generally uses resources more efficiently. Nitrogen input at crop rotation level was 22% lower under organic management, while nitrogen efficiency was 5% higher. Energy inputs showed even more dramatic differences, with 45% less energy used under organic management and 10% higher energy efficiency.
‘For both resource categories, the differences between organic and conventional production were primarily due to the specific type of on-farm processes (N₂-fixation by legumes, humus management, building soil fertility, nutrient mobilisation and nutrient cycling) of organic farming‘ (Sanders et al., 2025, p. 11).
These efficiency advantages were particularly pronounced at the whole farm level compared to the crop rotation level, and more evident on commercial farms than in experimental plots, suggesting that the integrated systems approach of organic farming delivers greater benefits when implemented holistically.
Animal welfare: a nuanced and species-dependent picture
Unlike the clear environmental benefits, the animal welfare assessment yielded more complex results. Following Fraser’s (2008) multi-dimensional model comprising ‘basic health and functioning, natural living/natural behaviour and affective states’, the researchers examined differences between organic and conventional animal husbandry across different livestock species.
Across all livestock species, organic management showed advantages in 32% of the comparisons, while conventional management performed better in 19%. No clear differences were found in 49% of the comparisons. However, these aggregate figures mask important species-specific variations.
Species distribution in the research
‘It is worth noting, that most of the comparative analyses we found dealt with dairy cows (278 of 445 pairs), while very few compared the animal welfare status for other livestock‘ (Sanders et al., 2025, p. 12).
This imbalance in research focus is significant, as the researchers had anticipated finding more pronounced differences between organic and conventional systems for monogastric animals (poultry and pigs) than for ruminants:
‘We expected more pronounced differences between organic and conventional animal husbandry for monogastric livestock (poultry and pigs), as the husbandry systems differ more than in dairy cattle husbandry‘ (Sanders et al., 2025, p. 15).
Dairy cattle: modest advantages with management dependencies
For dairy cattle, which represented the majority of the animal welfare comparisons, organic farming showed mixed benefits. The regulations regarding outdoor access and grazing provided some advantages for natural behaviour, but also introduced different health risks, particularly regarding parasite management.
The study found that organic farms performed better when addressing specific risk factors outlined in EU Organic Regulations. For example, requirements for litter and space had positive effects on lameness and leg health in dairy cattle. However, the provision of outdoor access, while beneficial for natural behaviour, created challenges with parasite contamination that required careful management.
Monogastric animals: greater potential benefits but limited research
Though underrepresented in the research, the available data suggested that organic standards for pigs and poultry could offer more substantial welfare benefits compared to conventional systems. This is primarily because the differences in housing and management between organic and conventional systems are more pronounced for these species:
- for pigs, organic requirements include access to outdoor areas, more space per animal, bedding materials for rooting and nesting behaviours, and restrictions on mutilations such as tail docking. These provisions align well with pigs’ natural behavioural needs and potentially offer significant welfare advantages, though the authors note that the limited number of studies prevents definitive conclusions;
- for poultry, organic standards similarly provide for outdoor access, lower stocking densities, and requirements for natural light and perching, which could better accommodate natural behaviours. However, the researchers found few comprehensive studies comparing health outcomes between organic and conventional poultry systems.
Breeding practices and genetic considerations
The study acknowledges that breeding practices differ significantly between organic and conventional systems, though this aspect has received insufficient research attention. Conventional livestock production often relies on breeds selected primarily for high productivity, sometimes at the expense of other traits related to robustness, longevity, and adaptability to less controlled environments.
In contrast, organic regulations encourage the use of breeds adapted to local conditions and resistant to disease, with an emphasis on preserving genetic diversity. However, in practice, many organic farmers still use the same high-yielding breeds common in conventional systems, particularly for dairy cattle.
The researchers note:
‘Management factors are of greater importance than production system‘ (Sanders et al., 2025, p. 12).
This finding suggests that while organic standards provide a framework that could support better animal welfare, the implementation at the farm level and the specific management choices, including breed selection, ultimately determine welfare outcomes.
Health, behaviour, and emotional state
The analysis showed that animal health was better in the organic variant in 129 of 420 pairwise comparisons. No clear differences were found in 208 pairs, while the conventional variant demonstrated better health outcomes in 83 pairs.
Regarding natural behaviour and emotional states, the empirical basis was much weaker. From the limited available data, 7 of 16 pairs showed advantages for organic farming in supporting natural behaviours, with no differences found in 7 pairs. For emotional states, 5 of 9 pairs indicated better outcomes under organic management.
The researchers concluded:
‘Organic farming offers great potential for good animal welfare, but the current legislative framework does not guarantee it‘ (Sanders et al., 2025, p. 12).
This suggests that while organic standards create conditions that can support better welfare, the translation of these standards into actual welfare outcomes depends on farm-specific implementation and management practices.
Veteinary drugs
The study also addressed veterinary pharmaceuticals, noting:
‘For veterinary drugs from animal production, an advantage can be assumed due to restrictive production rules but has not been empirically proven‘ (Sanders et al., 2025, p. 5-6).
This reflects the organic standards’ more restrictive approach to antibiotic and pharmaceutical use in livestock, though the researchers acknowledge the need for more empirical research in this area.
Discussion: systems approach as key to benefits
A particularly important insight from this research is the identification of organic farming’s systems approach as the primary driver of its environmental benefits. The researchers explain:
‘The differences between organic and conventional agriculture in the provision of public goods are in particular a result of the system approach pursued in organic farming. This approach is characterized in particular by (a) the linking of individual agroecological system elements and the use of synergy effects, as well as (b) the consideration of natural system boundaries and capacities‘ (Sanders et al., 2025, p. 13).
This systems approach typically leads to more diverse crop rotations, lower production intensity, and simultaneous provision of multiple environmental benefits. For example, the prohibition of synthetic nitrogen fertilisers in organic farming naturally leads to greater reliance on legumes, which provide numerous benefits beyond nitrogen fixation, including carbon storage, weed control, soil structure improvement, and habitat provision for insects and other fauna.
Implications and future directions
The researchers acknowledge that while organic farming provides clear environmental benefits, yield gaps between organic and conventional systems remain a challenge. They suggest two complementary approaches to address this issue:
- improving yields in organic systems based on organic principles;
- reducing the relevance of yield gaps through changes in consumption patterns (e.g., reducing food waste and animal product consumption)
For animal welfare specifically, future research needs to:
- expand investigation beyond dairy cattle to include more comprehensive assessments of pigs, poultry, and other livestock species
- examine the interaction between breed selection and management systems;
- develop better metrics for assessing natural behaviour and emotional states;
- identify specific management practices within organic systems that consistently improve welfare outcomes.
The study concludes that organic farming can significantly contribute to solving current environmental and resource challenges and represents a key approach for sustainable land use. However, improving animal welfare would require going beyond current organic regulations to address farm-specific management factors.
Limitations and future research needs
Despite its comprehensive nature, the study acknowledges certain limitations. Data heterogeneity and varying experimental designs mean that some indicators show mixed signals. Future research should:
- take specific aspects into greater consideration by comparing whole farming systems;
- include different intensities of cropping systems and surrounding landscapes;
- focus on yield optimisation based on organic principles;
- investigate more thoroughly the animal welfare aspects of organic farming, particularly for livestock other than dairy cows;
- develop standardised methodologies for comparing welfare outcomes across different production systems.
Conclusion
This landmark study provides the most comprehensive assessment to date of organic farming’s environmental and animal welfare benefits. The findings strongly support organic agriculture as a sustainable farming approach with clear advantages for water protection, soil conservation, biodiversity, climate protection, and resource efficiency. While animal welfare benefits are less conclusive and more species-dependent, the overall evidence suggests that organic farming can play a vital role in addressing current environmental challenges in agriculture.
As the authors conclude: ‘Organic farming clearly provides a range of environmental benefits. Consequently, it may contribute to solving current challenges in this field and is rightly considered a key approach for sustainable land use‘ (Sanders et al., 2025, p. 16).
Dario Dongo
References
- Sanders, J., Brinkmann, J., Chmelikova, L., Ebertseder, F., Freibauer, A., Gottwald, F., Haub, A., Hauschild, M., Hoppe, J., Hülsbergen, K.-J., Jung, R., Kusche, D., Levin, K., March, S., Schmidtke, K., Stein-Bachinger, K., Treu, H., Weckenbrock, P., Wiesinger, K., Gattinger, A., & Heß, J. (2025). Benefits of organic agriculture for environment and animal welfare in temperate climates. Organic Agriculture. https://doi.org/10.1007/s13165-025-00493-w
- Burtscher-Schaden, H., Durstberger, T., & Zaller, J. G. (2022). Toxicological comparison of pesticide active substances approved for conventional vs. organic agriculture in Europe. Toxics, 10(12), 753. https://doi.org/10.3390/toxics10120753
- Fraser, D. (2008). Understanding animal welfare. Acta Veterinaria Scandinavica, 50(S1). https://doi.org/10.1186/1751-0147-50-S1-S1
- Gattinger, A., Muller, A., Haeni, M., Skinner, C., Fliessbach, A., Buchmann, N., Mader, P., Stolze, M., Smith, P., & Scialabba, N. (2012). Enhanced top soil carbon stocks under organic farming. Proceedings of the National Academy of Sciences, 109(44), 18226-18231. https://doi.org/10.1073/pnas.1209429109
- Tuck, S., Winqvist, C., Mota, F., Ahnstrom, J., Turnbull, L., & Bengtsson, J. (2014). Land-use intensity and the effects of organic farming on biodiversity: A hierarchical meta-analysis. Journal of Applied Ecology, 51, 746-755. https://doi.org/10.1111/1365-2664.12219
- Tuomisto, H., Hodge, I., Riordan, P., & Macdonald, D. (2012). Does organic farming reduce environmental impacts? – A meta-analysis of European research. Journal of Environmental Management, 112, 309-320. https://doi.org/10.1016/j.jenvman.2012.08.018
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
