7/2/2013 - By Dr. Raymond Snyder

Role:

Nitrogen is the mineral element that plants require the most.  Nitrogen is used primarily for chlorophyll production.  Furthermore, Nitrogen serves as constituent of many plant cell components, including amino acids and nucleic acids.  Nitrogen is a mobile element within the plant.

Nitrogen influences many turfgrass plant responses.  Nitrogen generally increased color and shoot growth.  Proper Nitrogen levels have a positive influence on carbohydrate formation, recuperative ability, density, and disease tolerance.  Excessive Nitrogen levels negatively influence lateral shoot growth and density, root growth, and disease tolerance.  Excessive Nitrogen also decreases stress tolerance associated with heat, cold, drought, and traffic.

Requirement:

Turfgrass generally consists of 2 -6 % Nitrogen.  Table 1 provides specific Nitrogen sufficiency ranges from leaf analysis for turfgrass.

Table 1.  Sufficiency nitrogen ranges from leaf analysis for selected turfgrass types.

Uptake Sources:

Foliar – For foliar absorption, urea is absorbed more than nitrate and ammonium.

Roots – Nitrate and ammonium are the primary forms of N absorbed by roots.

Deficiency:

Nitrogen deficiency in turfgass is usually expressed as a pale yellow-green colored referred to as chlorosis.  Chlorosis indicates a reduction in chlorophyll production.  Nitrogen deficiency is usually first expressed in lower (older) leaves.  Severe Nitrogen deficiency results in reduced shoot growth and density resulting in weak turf that has difficulty recovering from damage and stress.

Nitrogen deficiencies are easily correctable.  Both foliar and root targeted Nitrogen applications can quickly correct Nitrogen deficiencies in turfgrass.  The proper use of foliar and granular Nitrogen sources significantly reduces the chance that a Nitrogen deficiency will occur in turfgrass.

Sources:

1. McCarty, L.B.  Best Golf Course Management Practices.  2001.
2. Taiz, L and Zeiger, E.  Plant Physiology.  1998
3. Photos provided by George H. Snyder, Ph.D.