Nutrient Deficiencies in Turf

Nitrogen

Nitrogen is required in the highest amount compared to the essential elements except for carbon, oxygen and hydrogen. Turfgrass contains nitrogen on a dry matter basis between 2.5 to 5 percent in most normal situations. It is important for color, growth rate, density, pest occurrence, and stress tolerance by serving as a vital constituent of the chlorophyll molecule, amino acids and proteins, nucleic acids, enzymes and vitamins.

Deficiency symptoms include yellowing and stunting of growth occurring in the older leaves first and are most common on sandy soils where clippings are collected. 

Phosphorus

Phosphorus is important for the carbohydrate transport system that moves energy to all parts of the plant for growth processes. Phosphorus is extremely important for root development and for increasing stored carbohydrates that help supply consistent energy for the plant throughout the year. 

Deficiency symptoms first appear on older leaves by showing a dark-green coloration with a reddish-purple pigmentation along the leaf-blade margins. Phosphorus is immobile in the soil; therefore, foliar applications are necessary for quickly delivering phosphorus directly to the plant.

Potassium

Potassium is important for the control and regulation of water; it balances water within the cells and loss through transpiration. Potassium helps increase heat, cold, drought, wear, and pest tolerance. Turfgrass requires potassium in large quantities, second only to nitrogen and is usually stored in larger quantities than required for normal plant growth.

Deficiency symptoms occur on older leaves by showing interveinal yellowing, rolling, and burning of the leaf tip, eventually forming necrotic spots on leaf margins.

Calcium

Calcium in turfgrass ranks third after nitrogen and potassium, and is relatively immobile and usually found in the older leaves. It is required for cell division and is important for cell membrane permeability, also present in the middle lamella acting as a glue to hold cell walls together.

Deficiencies occur most commonly in sandy soils with low cation exchange capacity, extremely acidic (<5.0 pH) soils, and soils saturated with sodium. Deficiency symptoms occur on younger leaves and may appear as distorted, twisted or deformed. These leaves turn reddish-brown along the margins then becoming rose-red, finally leading to leaf tips and margins that wither and die. Roots also suffer by becoming short and bunched, thus, decreasing the turf's nutrient uptake potential and ability to withstand abiotic and biotic stress factors.

Magnesium

Magnesium is an important constituent of chlorophyll, acts as a carrier of phosphorus, and activates plant enzymes for carbohydrate and phosphate metabolism.

Deficiency symptoms most commonly occur in acidic sandy soils with low CEC or soils with high pH. Symptoms begin with a slight discoloration of the lower leaves followed by interveinal chlorosis with green veins and eventually older leaves turn blotchy-red with yellowish streaks between the parallel veins.

Sulfur

Sulfur is required for protein synthesis and is used as a constituent of proteins and chlorophyll.

Deficiencies commonly occur on soils low in organic matter and where grass clippings are collected. Symptoms resemble nitrogen deficiency with pale, yellowish-green leaves and are more pronounced on newer leaves with scorched leaf-tips along the margins.  

Boron

Boron is important for auxin metabolism in root elongation, protein, and utilization of calcium and phosphate.

Deficiencies are most common in high pH and sandy soils. Boron is relatively immobile and higher concentrations are usually found in the leaf tips. Symptoms include thickening, curling and rosette appearance with interveinal chlorotic streaks occurring first on new growth.

Copper

Copper is important for the production of enzymes used as catalysts in plant metabolism and is connected with the light reaction during photosynthesis.

Deficiency occurs on sandy soils with high pH and where levels of nitrogen, phosphorus, iron and zinc are in excess. Symptoms include chlorosis of new leaf tissue with bluish tips becoming yellow to necrotic progressing from the leaf tips to the base.

Iron

Iron is typically the micronutrient that is most commonly deficient in turfgrass, and generally, deficiencies are a result of iron insolubility. It is important for chlorophyll and cytochrome production, and critical for the cellular respiratory system.

Deficiencies are common in soils with high pH, calcium, zinc, manganese, phosphorus, copper, and bicarbonate levels in irrigation water. Symptoms include interveinal chlorosis on newer leaves that eventually turn whitish; these symptoms typically appear more severe on closely mowed turf, therefore, iron directly affects turfgrass aesthetics.

Manganese

Manganese is an important component of photosynthesis, and is involved in carbohydrate (nitrogen) metabolism, chlorophyll synthesis, enzyme activation and oxidation-reduction process.

Deficiency symptoms commonly occur in alkaline soils high in calcium, iron, copper, zinc, potassium, and sodium with low CEC. Symptoms include interveinal chlorosis with veins remaining green on new growth, and distinct, necrotic leaf spots may develop on older leaves. A mottling effect with limited response to nitrogen may become noticeable on closely mowed turf.

Molybdenum

Molybdenum is utilized by turfgrass in small amounts and required for the reduction process of nitrogen to produce amino acids and proteins. Unlike other micronutrients, Molybdenum is more available under alkaline conditions.

Deficiencies results in reduced protein synthesis and are common in acid sands. Symptoms slightly resemble nitrogen deficiency with pale, yellow-green stunted plant tissue.

Zinc

Zinc is important in the synthesis of certain plant hormones and auxins for promoting growth.

Deficiencies commonly occur on alkaline soils with excessive copper, iron, manganese, nitrogen, phosphorus and soil moisture. Symptoms include mottled-chlorotic appearance with rolled leaves; on closely mowed turf, symptoms may appear as desiccation.