So many people keep assuming the worse rolls like you never get a seed back any time. Its 50/50. LotL 3 ON AVERAGE gives MORE food back in A20 then it did in A19 since the average is 3.5 yield in A20 vs 3 yield in A19. And with LotL 3, you will never run a negative even in the worse...
Bit of your math is way off. 1 Point while gives SLIGHTLY less then A19, still give profit.
Base Line - 10 Plants
LotL = 0
A19 - 10 Crops
A20 - 20 Crops (but 25 need to be used for 5 seeds)
A20 Has a Net Loss of 5 Crops if replanting
A19: 10 > A20: -5
LotL = 1
A19 - 20 Crops
A20 -...