Dollar for dollar, fertilization does more to improve poor-quality turfgrass or to maintain good-quality turfgrass than any other management practice. Proper fertilization practices produce a dense, medium- to dark-green turf that resists pests and environmental stresses.
Careless application techniques or excessive amounts of fertilizer applied at the wrong time of year can result in serious turf damage and contamination of water resources. Successful turf maintenance fertilization requires that you assess your turf’s nutritional requirements, understand fertilizers, know how much to apply and when, and use proper application techniques.
Turfgrasses require at least 16 nutrients for normal growth and development. Some nutrients are needed in large amounts, other nutrients only in minute quantities. Regardless of the amount required, a deficiency of any of these nutrients will limit the growth and development of your turf. Thus, a calcium deficiency can be just as detrimental to the plant as a lack of nitrogen, even though turfgrasses use more nitrogen than calcium.
Nine of the sixteen required nutrients are needed in much larger quantities than the other seven. These nine nutrients—carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur—are called macronutrients. Carbon, hydrogen, and oxygen make up about 90 to 95 percent of the plant’s dry weight. They are never deficient in turfgrasses because they are derived from carbon dioxide (CO 2 ) and water (H 2 O).
Nitrogen, phosphorus, and potassium are referred to as primary nutrients and must be supplied periodically to turf through fertilizer applications. Calcium, magnesium, and sulfur, the secondary nutrients, are needed only occasionally in the form of fertilizer or lime.