Farmer Fred is in trouble! For the last five years, he has been getting less and less corn from his fields and is barley making ends meet. He thinks it’s because his soil quality is rapidly declining but why?

Perhaps you can help him find out! We’re sending you his fields and crops plan, but we are missing a critical piece of information - the humus balance. Humus balance is a great metric of general soil health - the more humus the better!

Please implement the humus balance calculator so Mr. Fred could start fixing his soil for the future.

Your task is to implement a simulation of how different crops might affect the field's health. Since the calculations in real life will be very complicated, the data should be calculated in the server and results fetched to the front-end.

How to calculate humus balance based on our data?

• Each crop has a humus_delta showing how it affects the field.
• Add up all the humus_deltas of the field's crops over the years.
• For each consecutive year the crop is on the field, multiply its effects by 1.3

• Calculator is implemented in the back-end
• Humus balance is fetched at page load for all fields
• Humus balance is fetched at every crop change
• Tests pass
• No page reloads (crop changes will be lost since we're using hardcoded data in the server)
• The farmer should get visual feedback about whether he is improving or degrading his fields

• Ruby 3.0.0
• Yarn

• CD into the soil-service directory
• Run bundle install
• Make sure port 3000 is available on your machine
• Run bundle exec rails server

• CD into the crop-planner directory
• Run yarn install
• Make sure port 3001 is available on your machine
• Run yarn start
• Visit localhost:3001