What does ‘to be all in’ mean in this context? [closed]

I encountered the following sentence:

“This was not in fact an original idea, but was based on the English ‘Harvest Festival’, an old custom whereby people gave thanks to God once the crops were all in.”

What does “once the crops were all in” mean?

As mentioned in a comment, in this context it refers to the crops having been harvested. This is exemplified in the well-known Christian harvest hymn, where the qualification of ‘in’ makes this clear:

Come, ye thankful people, come,

Raise the song of harvest home!

All is safely gathered in,

Ere the winter storms begin;

God, our Maker, doth provide

For our wants to be supplied;

Come to God’s own temple, come;

Raise the song of harvest home!

This quotation is from Wikipedia. However the version I am familiar with from my (English) youth has:

“All be safely gathered in…”