Certified GKH Gardening Expert
This article will help you with your cherry tree: https://www.gardeningknowhow.com/edible/fruits/cherry/when-to-fertilize-cherry-trees.htm
Human urine, unlike most other mammals, does not break down into ammonia, fully, inside the body. This means that is contains a fair bit of urea, which the tree will have a hard time breaking down without the help of specialized bacteria. They may or may not be present in the soil.
What you may notice when you start using human urine is leaves turning yellow, pH dip WAY downward, and lockouts of potassium, phosphorus, magnesium, and calcium.
If you ferment it with hay, then compost, you will have a nutrient rich solution. I'm afraid, before that, it is not going to be very good for your tree.
One more thing to consider with human urine is metabolites that don't get processed fully, or remain in human urine. Some things that we consume are quite toxic, and even more so to plants. Feeding them our urine will be a death sentence to the tree without proper preparation.
This article will help you to fertilize Lemon Trees: https://www.gardeningknowhow.com/edible/fruits/lemons/learn-about-fertilizer-for-a-lemon-tree.htm