What does this mean?
The Agri-footprint methodology adequately represents perennial crops, one-year cycle and mixed crops (as the harvest land for each is reported separately to FAO), with the disadvantage that using FAOstat yield data means only the harvested area is considered but not any failed crops or fallow land.
Where crops are cultivated and harvested on the same plot of land, the Agri-footprint approach overestimates the area of land used because FAO counts the same area of land each time it is harvested.
To represent reality more accurately, we would need to acquire data on common crop cycles and associated crop combinations for each country covered by Agri-footprint. Not only this, a partition system would need to be defined to correctly allocate the land use to all the crops cultivated and harvested on the same plot of land during the course of a year. We would then either require information about the time the land was used (including resting periods) for each crop or use an allocation approach already in our database (economic, energy, mass).
The additional data required would be country specific and accessibility might vary from country to country in scope, methodology and quality, with some countries having a lot of information and others none at all. Differences in data availability and country specificity represent a challenge for inclusion in a life cycle inventory background database with a wide scope such as Agri-footprint.
The main challenge lies in the wide range of data sources that would be required to fully cover all crop/country combinations in Agri-footprint. Right now, to model land use we rely on one source, FAOstat, with the same scope, format and accuracy. Having to retrieve data for different countries, crops combination schemes and common crop cycles would require extensive data manipulation from sources with different levels of quality.
An initial way forward could be to focus on scenario 2 crops (multiple cycles for the same crop), which might be the easiest to model as no partition method would be required and it would be easier to investigate common crop cycle practices for a single crop.