Soil acidification, defined as a decrease in the acid neutralisation capacity of soil, is a major issue for agriculture, particularly for non-calcareous soils. In calcareous soils with high natural buffer capacity, there is little concern as pH remains stable and slightly alkaline until all carbonates are depleted, depending on their dissolution rate. However, in non-calcareous soils with low buffer capacity, especially sandy soils with low organic matter, acidification can cause a rapid decline in soil pH and base saturation. Soil pH is a key parameter for soil health as it affects the availability of nutrients and toxic elements (e.g. aluminium, cadmium, other heavy metals). Consequently, it impacts primary productivity, the quality of surrounding water bodies, and the habitat function for soil organisms and biodiversity. 
Soil amendments, including lime, biochar, industrial by-products, manure, and straw, can alleviate acidification. Quantitative insight into their effect on soil pH across Europe was limited, hampering appropriate use. Application of lime, biochar, by-products, manure, straw, and their combinations increased soil pH by 5–17% and crop yield by over 10%, especially on acidic soils. Yield increases lead to higher nutrient uptake, enhancing nutrient use efficiency and reducing losses to groundwater and surface water. Most amendments also increased cation exchange capacity, organic matter, and base saturation, improving soil health. Considering impact on pH, properties, yield, and cost, lime was most suitable for soils with pH below 5, while continuous manure supply and crop residue incorporation are valuable to avoid acidification in soils with pH above 5.  
Initial soil pH across Europe was often above the desired threshold for healthy crops. Frequent soil analysis helps monitor changes and take timely action. 

An increase in nitrogen use efficiency (NUE) is crucial to reconcile food production and environmental health. Optimised agricultural management strategies increase NUE and combine nutrient, crop, and soil management practices. Since the effect of these practices depends on local site conditions (i.e. soil fertility, climate, cropping system), we quantified how different measures contribute to increased NUE. This was done for the following measures: (i) combined fertilisation where organic and inorganic fertilisers are applied in various combinations to supply nutrients for crop growth and improve soil health via organic matter inputs, (ii) organic fertilisation where inorganic fertilisers are replaced by organic ones, (iii) use of enhanced efficiency fertilisers including controlled release fertilizers and inhibitors to avoid nitrogen losses during the growing season, (iv) right fertiliser rate where nutrient dose matches crop uptake and unavoidable losses, (v) right fertiliser timing where the nutrient dose is split over multiple applications to minimize losses, and (vi) right fertiliser placement where broadcast application is replaced by techniques such as banding, injecting or incorporation.  

On average, most measures had a positive impact on NUE, with increases from 8.6% for no-tillage to 13% with enhanced efficiency fertilisers. Sustainable fertilisation had strong positive effects on NUE, as these practices ensure crops receive adequate N during critical growth. Applying the right fertiliser rate reduces volatilisation, run off and leaching. Right timing of fertilisation can improve synchronisation of applied N with crop needs. Precise placement enhances N uptake in the rhizosphere and reduces ammonia volatilisation. Enhanced efficiency fertilisers slow N transformation, reducing losses. When optimal combinations are applied, crops get sufficient N and water bodies remain protected. 

Farmers are struggling with increasing difficulty of reconciling crop production with the number of environmental challenges they are facing. Where crops require sufficient nutrients to grow, adverse impacts on soil biodiversity, water quality, climate and terrestrial biodiversity occurs when too many nutrients have been applied. Since the fate of nutrients deviate from location to location, depending on weather conditions, crop type and management practices applied, there is urgent need for more holistic decision support systems. These decision support systems help to identify the main bottlenecks and management strategies to apply nutrients appropriately. Within NutriBudget we evaluated all current decision support tools being used across Europe and found that most of them use so-called nutrient budgets, implying the difference between nutrient inputs and crop uptake, as a guiding principle for sustainable nutrient management.  

Using innovative models, the NutriBudget project quantifies the desired state for those budgets in view of the various challenges for nature, soil, water and climate. This is done for carbon, nitrogen, phosphorus, potassium as well as sulphur, calcium, magnesium, copper, cadmium and zinc. Knowing both the current budget as well the desired budget informs farmers on the main challenges on field and farm level. It also helps to identify proper management measures to move towards the desired state, and allows one to prioritize the crop, soil, fertiliser and water management practices. Adjusting crop type and fertilisation to the local site conditions (i.e. knowledge of soil properties) helps farmers to sustain crop production, improve soil health and minimize undesired losses of nitrogen and phosphorus to air and water. Applying this new craftsmanship optimizes nutrient use without additional costs, allowing farmers to farm sustainably, whereas the nutrient budgets can be used to prove their contribution to a better environment.