Crop-Livestock Farming Systems Assessment in Europe

The goal of this study was to assess the environmental impacts of introduced innovations at farm level which integrate crop and animal production. A comparison of the LCA (Life Cycle Analysis) results between the base line (before introduction) and the innovative situation (after introduction) allows to identify whether the introduced innovation have environmental benefits or disadvantages.

LCA is a framework for estimating environmental impacts of a product or system while considering its entire life cycle, beginning with the extraction of raw materials, their transformation into inputs and infrastructure, and their use in the system of interest (ISO, 2006). When applied to agriculture, LCA's decomposition of farm inputs and activities into individual processes (with flows of matter and energy) renders the production chain explicit and allows the components of farm production with the highest impacts to be identified, which may lead to recommendations for decreasing them (van der Werf and Petit, 2002). LCA considers multiple categories of impact (e.g., acidification, eutrophication, climate change, energy use) so that possible transfer of impact (i.e., decreasing impacts in one category while increasing them in another) may be detected.

In the present study all stages of the agricultural production are included: the preliminary stage (i.e. the production of inputs and infrastructure), crop production (including land transformation), and animal production (Figure below). The system encompasses inputs into agricultural production (i.e. seeds, fertilisers, pesticides, feed, fuels, etc.), infrastructures (buildings, equipment, and machinery), and the agricultural production of plant and animal goods. The emissions in the preliminary stage are considered and referred to as ‘Indirect emissions'. Whereas the emissions occurring on the farm are named ‘Direct emissions'.

The temporal system boundary is one calendar year for permanent grassland and animals as well as for all production means. For arable crops the temporal boundary is from the harvest of the previous main crop until the harvest of the actual main crop. The latter is also valid for leys with the addition, that if the ley stays longer than the end of the assessed year the temporal boundary stops there.

For more information on LCA, you can read many resources on internet and begin by : https://en.wikipedia.org/wiki/Life-cycle_assessment

Agriculture has different functions for society and environment. According to Nemecek et al. (2004) different functions can be distinguished for LCAs of agricultural systems. Among them are:

1. The function of land cultivation, i.e. agricultural use of the soil. The aim is to cultivate a unit area during a certain time with as little environmental impacts as possible.

2. The productive function, i.e. the production of food and feedstuff. The aim is to produce a production unit with a minimised environmental burden.

Our study focuses on the first two functions, i.e. the land cultivation as well as the productive function. The following functional units (FU) were chosen:

• ha Utilized Agricultural Area and year, i.e. ha UAA*a, for the function of land cultivation

• Megajoule Digestible Energy, i.e. MJ DE, for the productive function. Here at farm level this means that all agricultural outputs (food and feed products) are converted into energy, which are digestible by humans. Products which are sold for animal production (e.g. barley, maize, grass silage) are also considered with an appraisal of the originating nutritional energy for humans. This is done by calculating conversion factors to appraise the later stage of transformation into food using standardized production scenarios.

The impact categories considered in this LCA are in the table below.

Here, we apply the LCA to 3 farms : "Ty Gwyn" an organic experimental dairy farm in UK (Wales), "San Giuliano", a conventional commercial dairy farm in Italy and "Midi Pyr", a conventional commercial pig farm in the South-West of France.