A farmer wishes to determine the optimal level of a new fertilizer on his soybea

A farmer wishes to determine the optimal level of a new fertilizer on his soybeancrop. Some factors that affect crop yield are fertilizer precipitation sunlight method of tilling the soil type of soil plant and temperature. Many of these factors cannot be controlled or manipulated to increase crop yield but the amount of fertilizer can be. An experiment is designed to study the effect of various amounts of fertilizer on crop yield. The soybean plants are randomly assigned to the different treatments.Treatment A: 20 soybean plants receive no fertilizerTreatment B: 20 soybean plants receive 2 teaspoons of fertilizer pergallon of water every 2 weeksTreatment C: 20 soybean plants receive 4 teaspoons of fertilizer pergallon of water every 2 weeksDiagram the experiment. Indicate the subjects of the experiment the explanatory variable and the response variable.