fanega = medida de superficie = "misura agraria equivalente a 64 are" -> "fanega" (Spanish bushel), land measure equivalent to 64 ares, 6,459.6 sq m (square meters)

Vocabulari - UPV
http://www.upv.es › upl
PDF
es fanega f en grain measure equivalent to 55.5 litres
fr fanègue f fanecada f. 2580
es hanegada f
en land measure equivalent to. 6,459.6 sqM
https://www.upv.es/upl/U0552821.pdf

The square meter, also called the meter squared, is the Standard International (SI) unit of area. The symbol for square meter is m2. Less formally, square meter is sometimes abbreviated sq m.
https://www.techtarget.com/whatis/definition/square-meter-me...

The fanega or Spanish bushel was an old measure of dry capacity in Spanish-speaking countries. It was generally used in an agricultural context to measure quantities of grain. The measure varied greatly, but in Castile, it was equivalent to roughly 55.5 liters.
It was also a measure of surface area that was further subdivided into 100 varas, or the amount of land that could be sown with a fanega of seed.
https://en.wikipedia.org/wiki/Fanega

Fanega
La fanega es una unidad de medida de la metrología tradicional española, anterior al establecimiento y la implantación del sistema métrico decimal. Es tanto una unidad de volumen o capacidad como una unidad de superficie, con gran variabilidad según la región. En el marco de Castilla, la conversión es 55,5 litros de capacidad o * 6459.6 metros cuadrados * para la fanega de superficie.
Se utilizaba para medir productos agrícolas (especialmente cereales) o áridos, y fincas agrícolas.
Se divide en dos cuartos, cuatro cuartillas o doce celemines.
https://es.wikipedia.org/wiki/Fanega


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Note added at 1 hr (2022-09-18 10:14:13 GMT)
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value dependent on the country in which it is being used
- Mexico : 8.81 acres, 3.57 hectares
- Spain (Castilla) : 6459.6 square meters

fanega - in British English
a unit of capacity, mass or land area used in Spanish-speaking countries, its value dependent on the country in which it is being used
Husbandmen rate their fields by the amount of wheat necessary to sow them: and thus speak of fanega land - a fanega being a measure of about two bushels

fanega - in American English
sostantivo parola: plural -gas (-ɡəz, Spanish -ɡɑːs)
1. a unit of dry measure in Spanish-speaking countries, equal in Spain to 1.58 U.S. bushels (55.7 liters)
2. a Mexican unit of land measure, equal to 8.81 acres (3.57 hectares)
https://www.collinsdictionary.com/it/dizionario/inglese/fane...

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Note added at 1 hr (2022-09-18 10:15:24 GMT)
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fanega = fanega land (approx. two bushels)

... in Castile (Harrap's) > 1.59 acres (agri., Simon & Schuster).

and is what I used out of fear of fanega or fanegada being mixed up by monolingual English readers with an old fogey or faggot.

The bushel, with 100 square areas, is equivalent to 59 centimeters, 59 square decimeters, or 1.6 square spans.