Which element is second most needed in order to sustain turfgrasses?

• A. Calcium
• B. Potassium
• C. Phosphorus
• D. Nitrogen

Answer: (B)

Understanding nutrient needs of turfgrass starts with recognizing which elements the plant must have in larger amounts. Nitrogen drives rapid green growth and overall vigor, making it the primary nutrient for lush turf. After nitrogen, potassium plays a central role because it supports many processes that keep the grass strong under stress. It helps regulate water balance in cells, activates a wide range of enzymes, promotes root development, and enhances tolerance to drought, heat, and cold while improving recovery after wear. These broad, stress-tolerance benefits mean turfgrass typically relies on a substantial amount of potassium, making it the next most-needed macronutrient after nitrogen. Calcium and phosphorus are important as well, but their day-to-day impact is usually less than potassium when soil levels are adequate. Potassium deficiency, for example, tends to show as poorer wear tolerance and reduced winter hardiness, which reinforces why potassium is prioritized after nitrogen in sustaining turfgrasses.