Liquidity Providers can earn $ASTRO by locking their LP tokens into a smart contract. This added incentive means to address the risk of impermanent loss that is part and parcel of providing liquidity in a DEX. (Please remember to always do your own research.)
The AstroSwap Solar Farm APR calculations include the rewards earned through being a liquidity provider and the rewards earned through staking LP Tokens.
The rewards are generated per block and distributed to each user based on their deposited amount at the end of each block.
For example, in the ADA-ASTRO farming pool, 1 $ASTRO is generated as the reward per block.
After 100 blocks are generated on the Velas chain, 100 $ASTRO are distributed to users based both on the amount they deposited and how long they deposited for.
If Astronaut Kirk deposited 10 ADA-ASTRO LP and Astronaut Yuri deposited 15 ADA-ASTRO LP, of the 100 $ASTRO distributed as rewards, Astronaut Kirk would get 40 ASTRO and Astronaut Yuri would get 60 ASTRO.
As more users lock more LP tokens, the APR will drop according to the proportion in which these new tokens are added.