Q.Growing cucmbers.
Why are my cucumber plants turning yellow and wilting? What is missing in the soil?

Yellowing leaves or plants can be due to watering issues; too much or too little, pests, disease, nutrient issues or environmental.
A soil test is the only way to determine if you have a nutrient issue or if the soil needs amendment. Your County Extension Office can help with a soil test for just a few dollars.
These links will help you with care requirements and will help you access the plants.
https://www.gardeningknowhow.com/edible/vegetables/cucumber/tips-for-growing-cucumbers.htm
https://www.gardeningknowhow.com/edible/vegetables/cucumber/when-to-pick-a-cucumber-how-to-prevent-yellow-cucumbers.htm
https://www.gardeningknowhow.com/extension-search/