What does Advanced Agriculture do in AoE3?

Field: Wood cost set to 0, XP for building set to 0, hit points +75%, build time −50%; Granary: hit points +75%, build time −50%. The game says: "Fields become free! Fields and Granaries gain more hitpoints and are built faster."

Home City card

Advanced Agriculture

Advanced Agriculture (tech ID DEHCAdvancedAgriculture) is a Home City card in AoE3: Definitive Edition 100.19.18309, in the decks of 2 civilizations, sent from the Discovery Age. Effect: Field: Wood cost set to 0, XP for building set to 0, hit points +75%, build time −50%; Granary: hit points +75%, build time −50%.

Quick answers (3)

Which civilizations have the Advanced Agriculture card?: Ethiopians and Hausa.
What does Advanced Agriculture do in AoE3?: Field: Wood cost set to 0, XP for building set to 0, hit points +75%, build time −50%; Granary: hit points +75%, build time −50%. The game says: "Fields become free! Fields and Granaries gain more hitpoints and are built faster."
What is the tech ID of Advanced Agriculture?: DEHCAdvancedAgriculture.

Fields become free! Fields and Granaries gain more hitpoints and are built faster.

What it does

Field: Wood cost set to 0, XP for building set to 0, hit points +75%, build time −50%
Granary: hit points +75%, build time −50%

Cost: 1
Sent from: I
Times it can be sent: 1
Game ID: DEHCAdvancedAgriculture

In these decks

EthiopiansI×1

HausaI×1

Source: techtreey.xml and the Home City files, AoE3: DE 100.19.18309 (build 25040513).