The main difference is that citizens live in republics while subjects live in monarchies.
They were on separate landmasses, but I'm not really sure this answers the question, you should try just asking google.
Answer:
High salt content in soil limits the ability of seeds to germinate, as well as plant growth and crop yields. Controlled leaching, typically through irrigation, removes or reduces to the total salt content in the soil, allowing for healthier crops.
Explanation:
