In agriculture, a bumper crop refers to a particularly good harvest yielded for a particular crop (wikipedia.org)
Leviticus 25:21 - The answer is, 'I will order my blessing for you in the sixth year, so the land will produce a bumper crop, enough to support you for three years. (The New Living Translation)
Joel 2:19-27 God answered and spoke to his people, "Look, listen - I'm sending a gift: Grain and wine and olive oil. The fast is over - eat your fill! I won't expose you any longer to contempt among the pagans. 20 I'll head off the final enemy coming out of the north and dump them in a wasteland. Half of them will end up in the Dead Sea, the other half in the Mediterranean. There they'll rot, a stench to high heaven. The bigger the enemy, the stronger the stench!" The Trees Are Bearing Fruit Again 21 Fear not, earth! Be glad and celebrate! God has done great things. 22 Fear not, wild animals! The fields and meadows are greening up. The trees are bearing fruit again: a bumper crop of fig trees and vines! 23 Children of Zion, celebrate! Be glad in your God. He's giving you a teacher to train you how to live right - Teaching, like rain out of heaven, showers of words to refresh and nourish your soul, just as he used to do. 24 And plenty of food for your body - silos full of grain, casks of wine and barrels of olive oil. 25 "I'll make up for the years of the locust, the great locust devastation - Locusts savage, locusts deadly, fierce locusts, locusts of doom, That great locust invasion I sent your way. 26 You'll eat your fill of good food. You'll be full of praises to your God, The God who has set you back on your heels in wonder. Never again will my people be despised. 27 You'll know without question that I'm in the thick of life with Israel, That I'm your God, yes, your God, the one and only real God. Never again will my people be despised. The Sun Turning Black and the Moon Blood-Red (The Message)
Luke 8:4-8 As they went from town to town, a lot of people joined in and traveled along. He addressed them, using this story: 5 "A farmer went out to sow his seed. Some of it fell on the road; it was tramped down and the birds ate it. 6 Other seed fell in the gravel; it sprouted, but withered because it didn't have good roots. 7 Other seed fell in the weeds; the weeds grew with it and strangled it. 8 Other seed fell in rich earth and produced a bumper crop. "Are you listening to this? Really listening?" (The Message)