**Source:** heavy metals from [SALCA](https://static-content.springer.com/esm/art%3A10.1007%2Fs11367-023-02255-w/MediaObjects/11367_2023_2255_MOESM7_ESM.docx) — SALCAheavymetal V1.0, Table 1, category `org_fert`; nitrogen contents from GRUDAF 2009 (Agroscope ACW/ART). Created on 2026-03-13, regenerated on 2026-08-10.

**Dataset:** SALCA

**Licence:** [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/)

**Citation:** Nemecek T., Roesch A., Bystricky M., Jeanneret P., Lansche J., Stüssi M., Gaillard G. (2024). Swiss Agricultural Life Cycle Assessment: a method to assess the emissions and environmental impacts of agricultural systems and products. Int J Life Cycle Assess 29(3), 433–455. https://doi.org/10.1007/s11367-023-02255-w

## Assumptions

Proxies used:

- Some terms, e.g., `peatKgMass` and `peatKgN` are not present in SALCA and there is not a good proxy for them, these have been recorded as incomplete and are missing heavy metal content values. The terms `organicFertiliserUnspecified` and `otherOrganicFertiliser` have also been recorded as incomplete.
- `compost` terms have been mapped to the generic `compost` row in SALCA, most of these are missing a dry matter value in HESTIA and the default SALCA value of 100 % dry matter has been used.
- `manure` terms that aren't in SALCA (e.g., sheep, goats) have been mapped to the manure unspecified term, with the exception of fish manure which has been left unmapped.
- All crop `meal` terms have been mapped to `Castor bean meal` in SALCA, which is the only crop meal term available.

SALCA values were converted from per kg dry matter using the below methods:

- For `DryKgMass`, no conversion was required.
- For `FreshKgMass`, SALCA values have been converted by multiplying by the HESITA dry matter fraction for each term. If a HESTIA value was missing the (e.g., for `compostKgMass`) the SALCA dry matter value was used.
- For `DryKgN`, SALCA values have been divided by nitrogen fraction of the corresponding `DryKgMass` term.
- For `FreshKgN`, SALCA values have been multiplied by the dry matter fraction then divided by the nitrogen fraction of the corresponding `FreshKgMass` term.