$5.$ Explore the chemical composition of Calcium Ammonium Nitrate $($CAN$),$ its use as a nitrogen fertilizer, the safety concerns associated with its storage and handling, and regulations to mitigate risks.

$6.$ Discuss the dual role of sulfur and nitrogen in plant growth and the circumstances under which ammonium sulfate is the preferred fertilizer choice, considering soil conditions and environmental factors.

$7.$ Compare the water solubility and agricultural implications of different phosphate fertilizers such as superphosphate, triple superphosphate, MAP, and DAP, and how these characteristics influence phosphorus availability.

$8.$ Examine the role of potassium fertilizers in improving crop yield and quality, the factors influencing the choice between potassium chloride and potassium sulfate, including crop sensitivity and soil conditions.