The phrase "better yields" is exactly synonymous with "increased yields". A crop's yield is its volume, measured in bushels. There is literally no other way to interpret this.
Citation: I grew up on a farm, and my family has farmed for at least 200 years.
EDIT: This is a particularly weird reason to downvote me...
And that'd be pedantic. Better can be more cost-effective, cheaper in time or money or equipment or quality of land required. I grew up on a farm, live on one now, my family has farmed for 300 years, so I guess I win?
Citation: I grew up on a farm, and my family has farmed for at least 200 years.
EDIT: This is a particularly weird reason to downvote me...