Hello, everyone. I have doubts about the approach for land occupation and transformation in ecoinvent 3.

 

As I understood from the guidelines, here is how we calculate them:

Land Occupation [m2*year] = Duration of crop cycle (from cultivation to harvesting) x Area required to produce a unit of product (i.e., 1/yield)

Land Transformation [m2] = Land Occupation / Lifetime of the crop

 

Thus, for the annual crop (Duration of crop cycle = Lifetime of the crop), 

Land Transformation = 1/yield, 

Land Occupation  = Duration of crop cycle x 1/yield. 

If Duration of crop cycle < 1year, Land Occupation < Land Transformation (only compare values here); 

If Duration of crop cycle = 1, Land Occupation = Land Transformation ; 

If Duration of crop cycle > 1, Land Occupation > Land Transformation.

 

In dataset for 'sunflower production' [RoW] producing sunflower seeds, yield = 1032 kg/ha. Sunflower is an annual crop, and it lives for 125days.

Based on the above formulas, Land Transformation = 1kg/1032kg/ha = 9.69m2. Land Occupation = 125/365year*9.69m2=3.32m2*year. However, the dataset shows land occupation=12.112m2*year.

The dataset for 'onion production' [RoW] is also confusing. Yield =60t/ha but Land Transformation =0.307m2, lLand Occupation  = 0.204m2*year.

 

Are there any mistakes in my formulas?

Thanks for any help and best regards.