Life Cycle Assessment Method SALCA

salca

Agroscope’s life cycle assessment method, SALCA (Swiss Agricultural Life Cycle Assessment), offers an LCA method adapted to agricultural conditions. SALCA serves to calculate direct field and farm emissions, and also offers a range of impact assessment models that are appropriate for agricultural processes.

What is a life cycle assessment?

Life cycle assessment quantifies and evaluates the potential environmental impacts of a product or service. In analysing the entire life cycle, from the extraction of the raw materials up to the disposal or recycling of the waste, all of the environmental impacts associated with a product system are recorded. Here we aim for as complete a recording of all environmental impacts as possible, so that any shifts in the latter can be recognised. The method is laid out in ISO Standards 14040 and 14044.

Four separate stages are distinguished:

  • Goal and scope definition
  • Inventory analysis (calculation of emissions and resource consumption)
  • Impact assessment
  • Interpretation

Methodological development at Agroscope

Life cycle assessment was originally designed for industrial products and services. The aim of Agroscope's research is therefore to develop and recommend methods for determining emissions and environmental impacts for the agricultural sector, thereby enabling application of the LCA at crop, crop-rotation and farm levels. The main fields of application are arable and forage crops as well as dairy and meat production, but also the evaluation of farms in their entirety.

The most important specific developments for the creation of LCA's of agricultural processes are the following:

  • Systems analysis of agricultural production processes, e.g. taking account of multifunctionality
  • Emission models for agriculture-specific processes such as nitrate leaching, phosphorus emissions, heavy-metal flows and methane emissions.
  • Impact assessment methods for soil quality and biodiversity.

The SALCA Life Cycle Assessment Method

Agroscope's life cycle assessment method, SALCA (Swiss Agricultural Life Cycle Assessment) was established with the aim of offering a method adapted to agricultural conditions to all interested parties. It comprises our own developments for specific emissions and impact categories, as well as a range of established impact assessment models for applying LCA to agricultural processes. Originally developed for Switzerland, the method was also extended to adjoining countries, so that SALCA is also used in European projects.

Life cycle inventory

Several new methods have been developed for calculating direct field emissions for the life cycle inventory:

SALCA-Nitrate:

Nitrate leaching is defined as the surplus between supply to (mineralisation and fertilisation) and uptake by the plant. The model takes into account both the ploughing in of green manure and the ploughing up of meadows. Furthermore, leaching is not calculated for any crops during months with low precipitation and high growth rates. The nitrate remaining at the end of this period is regarded as being at risk of leaching. The method is applicable for the Swiss Central Plateau, and is being further developed for adjoining countries.

SALCA Heavy Metals:

A method for recording heavy-metal flows was developed, taking account of the heavy metals cadmium, copper, zinc, lead, nickel, chromium and mercury. Emissions into agricultural soil, into surface waters and into groundwater are determined taking into account the heavy-metal input from seeds, fertilisers, plant-protection products and feedstuffs, as well as deposition. An allocation factor is used to distinguish between diffuse inputs and those caused by agriculture. The method makes use of generic data for Switzerland.

SALCA Phosphorus:

This model for recording phosphorus emissions takes account of losses through soil erosion, surface run-off and leaching into the groundwater.


Life Cycle Impact assessment

SALCA Biodiversity (terrestrial):

The ‘Biodiversity' impact category encompasses 11 indicators (grassland flora, segetal flora, birds, mammals, amphibians, molluscs, bees, spiders, ground beetles, butterflies and grasshoppers). The biodiversity potential of each indicator in terms of species diversity and species composition is determined in two steps: first, agricultural activities are rated on the basis of their effects on the organisms. In a second step, the defined habitat types are weighted according to their importance for the indicators. Multiplying the ratings from steps one and two yields the final score. 

 

SALCA Soil Quality:

The ‘Soil Quality' impact category uses nine direct indicators expressing the effect of crop rotation on soil (soil depth, macropore volume, aggregate stability, humus content, heavy metal content, organic pollutants, microbial activity, earthworm and microbial biomass). Indirect indicators which can be derived from current management practice are used to determine these direct indicators. The model has been designed to record long-term changes in soil quality.

 

SALCA Pesticides:

Characterisation factors for active ingredients of pesticides were calculated according to the USES-LCA method and EDIP 97 as part of the ENDURE project (European Network for the Durable Exploitation of crop-protection strategies) funded by the European Union under the Sixth Framework Programme. The data necessary for the characterisation were made available by the University of Hertfordshire and the Julius Kühn Institute.