What are the signs of nitrogen deficiency in turfgrass?

Yellowing of older leaves and stunted growth are indeed classic signs of nitrogen deficiency in turfgrass. Nitrogen is a vital nutrient for plants, playing a crucial role in the formation of amino acids, proteins, and chlorophyll. When turfgrass lacks adequate nitrogen, it primarily affects the older leaves first because the plant reallocates its resources to sustain new growth. As a result, these older leaves turn yellow, a condition known as chlorosis. Additionally, stunted growth occurs because nitrogen is essential for overall plant vigor and development, leading to a less robust turf if deficient.

In contrast, the other options reflect symptoms more indicative of other issues. Wilting and browning leaf tips often signal water stress rather than nitrogen deficiency, while excessive root growth and poor color could result from an imbalance in nutrient availability or environmental factors. Increased pest activity and weed invasion are also less directly tied to nitrogen deficiency, as these issues often arise from a combination of factors including turf health, competitive strength of the grass, and overall soil health. Thus, recognizing the specific signs of nitrogen deficiency helps in accurately diagnosing and managing turfgrass health.