Nitrates are essential for plant growth, but they become a problem when they leave the soil before crops can absorb them. They can then move into groundwater, rivers and ultimately the sea. The European Commission published the first comprehensive evaluation of the EU Nitrates Directive on 15 July 2026. Its conclusion is measured: the rules have improved farming practices and reduced some nutrient losses, yet nitrate pollution remains widespread.

The review comes as mineral fertiliser use has risen again. According to Eurostat, EU agriculture used 9.8 million tonnes of nitrogen and phosphorus mineral fertilisers in 2024, 6% more than in 2023. This was still below the relative peak recorded in 2017, but it underlines a basic principle: every unit of nitrogen that is bought, transported and spread is useful only if a crop can actually take it up.

For farmers and gardeners, the practical choice is not between feeding plants and protecting water. It is about supplying the right nutrient, at the right rate, in the right place and at the right time. This is the core of balanced fertilisation.

What did the EU’s 2026 evaluation find?

The Nitrates Directive was adopted in 1991 to prevent and reduce agricultural nitrate pollution. In designated vulnerable zones, it governs matters such as spreading periods, application near watercourses and the amount of nitrogen from livestock manure. The common limit in these areas is 170 kilograms of nitrogen from manure per hectare per year.

After more than three decades, the Commission considers the directive overall effective, relevant and economically justified. The evaluation estimates the cost to European society of agricultural nitrogen pollution, across all forms of nitrogen, at between €68 billion and €182 billion per year. The directive’s benefits are estimated at €10 billion to €22 billion a year, while annual implementation costs are put at €2.8 billion to €3.1 billion. These are EU-wide estimates rather than individual bills; they include impacts on drinking water, ecosystems and economic activities that depend on clean water.

The report does not claim that the problem has been solved. Nitrate can persist in groundwater, so better practice may take years to produce a visible change. The Commission also identifies stagnant or deteriorating water quality in some areas, despite more recent reductions in several agricultural pressures. It calls for smarter implementation that responds to local conditions, climate change and regions where livestock production and manure are highly concentrated.

How do nitrates move from land into water?

Plants take up most nitrogen while they are actively growing. If more nitrogen is supplied than the crop and soil can retain, the remainder is exposed. Nitrate dissolves readily in water, so water moving through the soil can carry it into groundwater. This process is known as leaching. At the surface, runoff can also move nutrients into ditches, streams and ponds.

Risk therefore depends on timing and weather as well as on the total amount applied. Spreading on saturated, frozen or snow-covered ground, or just before heavy rain, makes losses more likely. Splitting applications across periods of active growth can help crops capture a larger share of the available nitrogen.

In rivers, lakes and coastal waters, excess nitrogen and phosphorus can drive unusually rapid growth of algae and other plants. Their decomposition then consumes oxygen. This process, called eutrophication, disrupts fish, invertebrates and aquatic ecosystems, and can make drinking-water treatment more difficult.

What do the new figures show for France?

The Commission’s France report covers 2020-2023, but the water-quality measurements used in the country fiche relate to 2023 alone. This caveat matters: the percentages should not be read as a four-year average.

Among 2,510 groundwater monitoring points, 12.4% had an average nitrate concentration at or above 50 mg/L, the threshold used in EU drinking-water rules and to identify polluted or at-risk waters. When sites between 37.5 and 49.99 mg/L with a rising trend were added, 19.8% of groundwater sites fell into the two alert categories used by the report.

The national figure conceals contrasting trends. Between 2019 and 2023, concentrations fell at 31.6% of groundwater monitoring points and rose at 33.9%. At sites already at or above 50 mg/L, increases were more frequent than decreases. The Commission also notes that France’s groundwater monitoring density, about four stations per 1,000 square kilometres, was below the EU average cited in the fiche.

For surface water, 99.2% of monitoring points were below 50 mg/L. That does not mean all ecological risks were low: 52.1% of sites with a reported trophic status were classed as eutrophic or at risk of becoming eutrophic. This was an improvement from 55.2% in the previous reporting period. Monitoring networks, criteria and methods can change, so the report recommends broader and more representative data before drawing quick comparisons.

Has fertiliser use started rising again in Europe?

Eurostat data released on 26 June 2026 show that EU agriculture used 8.9 million tonnes of nitrogen mineral fertilisers in 2024, 5.8% more than in 2023. France had the largest volume, at 1.8 million tonnes. EU use of phosphorus fertilisers reached 0.9 million tonnes, a year-on-year rise of 7.7%.

These totals do not measure the efficiency of an individual farm or the amount reaching water. A large agricultural country will naturally use more than a small one, and a tonne sold is not a tonne leached. The data nevertheless provide useful context: after several years of decline and sharp price fluctuations, use rebounded. Precise nutrient management therefore matters even more.

A 2026 report by the Commission’s Joint Research Centre concludes that integrated nutrient management and lower excess inputs can reduce environmental impacts without significant yield losses. The aim is not to starve a crop, but to stop nitrogen paid for by the farmer from mainly feeding losses.

How can gardeners fertilise more accurately?

A vegetable garden operates on a different scale from a farm, but water follows the same physical rules. An extra handful of fertiliser “just in case” may be wasted if the soil is already fertile, the crop is close to harvest or intense rain moves nutrients away before roots can use them.

1. Observe before adding nutrients

Identify the crop, its growth stage and the condition of the soil. Leafy vegetables generally have different needs from legumes or fruiting crops. Soil enriched with mature compost over several seasons does not automatically need another application. If uncertainty persists, a soil test is more useful than repeated guesswork.

2. Split applications

Two modest applications during active growth are often easier for plants to use than one large dose supplied far in advance. Follow the product rate and measure the area being fertilised. “Natural” does not mean nitrogen-free: manure, poultry litter, liquid feeds and compost can all release nutrients.

3. Check weather and soil moisture

Do not fertilise saturated, frozen or snow-covered soil, or immediately before heavy rain. On very dry ground, careful rewetting followed by an application close to the root zone can reduce loss and plant damage. Keep fertiliser away from ditches, ponds and streams, even in a small garden.

4. Avoid leaving soil bare without reason

After harvest, a suitable cover crop can capture residual nitrogen rather than leaving it available to leach during rainfall. Well-managed organic mulch can also protect soil structure, but it does not replace nutrient accounting. Depending on the material and its stage of decomposition, mulch may temporarily retain or release nitrogen.

What changes at farm scale?

On a farm, precision begins with a budget: expected crop demand, nitrogen already in the soil, previous crops, the composition of manure or slurry, and only then any additional mineral fertiliser. Soil and manure analysis, decision-support tools, split applications and accurate records help bring the applied rate closer to the useful rate.

Grass buffers, cover crops, rotations and no-spread zones beside water complement this work. They do not cancel out excessive application, but they reduce pathways into water. In regions with very dense livestock production, the Commission says the common per-hectare manure limit may not be sufficient on its own; surplus manure also needs to be managed across the wider territory.

Circular nutrient use has real potential, provided recycling is not confused with harmlessness. Processing or moving manure to an area with a genuine nutrient need can reduce demand for mineral fertiliser. But recycled nitrogen remains nitrogen: it must be analysed, counted and applied when plants can absorb it.

Does climate change make fertilisation harder?

Yes, because it makes timing less predictable. Drought can slow crop growth and nutrient uptake; a later downpour can then move unused nitrogen. Milder winters may also shift growth periods and practical spreading windows. The EU evaluation finds that the directive can respond without a complete legal rewrite, but local implementation needs to become more flexible and better grounded in actual conditions.

Adaptation does not mean spreading whenever it is convenient. It means linking each decision more closely to soil conditions, weather forecasts, crop needs and water risk. The France report specifically recommends wider sharing of scientific knowledge and good practice so nitrate action programmes are better prepared for climate change.

Making each harvest useful through local networks

Using nitrogen more efficiently helps produce food without transferring part of the cost to water and biodiversity. Yet a well-grown harvest can still be wasted if it cannot find an outlet in time. Balanced fertilisation and food-waste prevention operate at different stages of the same chain: one avoids unnecessary resource use, while the other prevents already-grown food from being discarded.

Seeed enables individuals and producers to give, sell or swap harvests and local products with people nearby. For a gardener with too many courgettes or a producer with a small batch available, that connection can extend the value of the harvest. It does not clean a polluted aquifer or replace agricultural policy, but it can reduce food waste within a neighbourhood or local area.

Key points

  • Nitrates feed plants, but excess nitrogen can pollute groundwater and contribute to eutrophication.
  • The 2026 EU review finds the directive useful while calling for more precise, locally adapted implementation.
  • In France, 12.4% of monitored groundwater sites in the 2023 data were at or above 50 mg/L.
  • Good practice means measuring, splitting applications, checking the weather and covering soil where appropriate.
  • Recycled manure or compost is valuable only when its nitrogen is included in the crop’s actual nutrient budget.

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