Improvements

The database is continuously being improved by the Agri-footprint team. Recently we took a closer look at how much seed is applied, for all crops, and how seed cultivation is modelled. Based on new insights, three aspects of our methodology for dealing with seed material in LCI development have been improved:

• the amounts of start material derived from FAO statistics have been refined;
• the gaps in data on the amount of seed material have been filled;
• the seed cultivation process has been improved.

Seed input and production in earlier versions

Since Agri-footprint version 3.0 seed production and application are included in the inventories of products. The amount of seed material used for crop country combination is based on seed production statistics specific for each crop and country, derived from FAO statistics. The process of seed cultivation is assumed to be similar to the cultivation process itself (e.g. the inputs of fertilisers, pesticides, etc.), but with a correction for yield.

Improvement 1: Amount of start material derived from FAO statistics

The improvement in the method for determining the amount of start material from FAO statistics can best be illustrated using an example. The figure shows the yield and seed input for various rapeseed cultivation LCIs in Agri-footprint. The amount of seed material varies considerably between countries, even among neighbouring countries. Similar patterns are observed for other crops. To avoid huge, unexplainable differences in seed input between different datasets for the same crop, it was decided to use crop global averages for seed input.

Improvement 2: Gaps in the data on the amount of seed material

For some product groups like vegetables, FAO statistics do not report anything about the amount of starting material applied for each crop. These data gaps were filled by using data from various sources, like KWIN-AGV (Wageningen UR, 2015), concerning the amount of seed material that is applied for different crops.

Improvement 3: Improvement of the seed cultivation process

The seed cultivation processes in AFP 3.0 and 4.0 versions are basically a copy of the cultivation process, with a correction factor for the yield. Previously, the correction factor, or yield ratio, was set at 80% of the yield used for all cultivation processes. Hereby is assumed that the seed cultivations have more environmental burden than the cultivation itself. This approach works well for products that are similar to the seed material, such as most cereals (wheat, barley, etc.) and forage legumes (soybean, lupine, etc.), but it is not realistic for products like vegetables. To solve this, the next update of Agri-footprint will use specific correction factors for various product groups based on data from Feedprint. Different yield ratios are used for cereals, maize, oil seeds, grasses, forage legumes, grain legumes and sugar beet. Yield ratios for vegetables are assumed to be similar to sugar beets.