Would the earth have soap if plants did not exist?
No, the earth would not have soap if plants did not exist. I believe this because soap plants (of the genus Chlorogalum) are essential to our making of soap. We use these plants to make all kinds of soap, by using the sap of these plants. However because this does not complete the question, I will explain further. Plants are the only way that the compound 'saponin' exists. Saponin forms the bubbly lather.
No. Dish soap can be used to kill off some common pests such as aphids, but large amounts or failing to wash it off can chemically burn the leaves. I cant imagine what the roots would do! I expect a plant growing in dish soap would die in a day or two. Actually, I did a science project that included using dish soap on plants instead of water and the plant turned out very good…
Soap water would have a negative affect on the plant and would probably cause it to die or not sprout because the chemicals in these soaps are harmful to plants, these chemicals are used to kill bacteria and most of these bacteria help in the bulding up of nitrates in the soil, without thes nitrates the plants may die