Mineral Nutrition Requirements for Bermuda Grass Grown on a Professional Soccer Field H. Rodríguez-Fuentes 1 , K. Acuña-Askar 1 , J.A. Vidales-Contreras 1 , J. Rodríguez-Absi 1 , G. Jiménez-García 1 , M.A. López-Jiménez 2 and J.C. Rodríguez-Ortíz 3 1 Universidad Autónoma de Nuevo León, Mexico 2 Universidad Veracruzana, Mexico 3 Universidad Autónoma de San Luis Potosí, Mexico Keywords: Cynodon dactylon Rich, sports turf, hydroponics, growth modeling, fertilization, consumptive use Abstract The efficient use of irrigation water and turf nutrition in sports fields requires the development of a management program oriented to attain both, esthetics (plant density, color and height) and sustainability. The hydroponic system under study consisted in a professional soccer field made up of sand and Bermuda grass (Cynodon dactylon). A turf nutrition and irrigation program was developed from plant nutrient removal analysis, dry matter accumulation growth data and plant water use calculations. Turf growth, measured as dry matter accumulation was adjusted using a three parameter sigmoid model (R 2 =0.981). By deriving the growth equation the maximum daily rate of dry matter accumulation was 0.579 g m -2 day -1 . Calculation of daily water evapotranspiration rate was 4.29 mm day -1 . The developed hydroponics management protocol suggests that the amounts of macronutrients (g) that should be applied to the sport field per week per m 2 must be: N, 1.74; P, 0.184; K, 0.83; Ca, 0.576 and Mg, 0.266 Along with macronutrients, the quantities of micronutrients (in mg) should include Cu, 0.361; Fe, 1.87; Mn, 1.53 and Zn, 2.25. Split doses of macronutrient and micronutrient solutions into three equal fractions for the first three irrigations each week is recommended. INTRODUCTION Bermuda grass (Cynodon dactylon) is used in warm weather sports fields, and is a compact and dense turf with a uniform growth profile. In addition, Bermuda grass has high tolerance to water stress at high temperatures, endures walk over and resprouts after low-height mowing (Trenholm et al., 1998). The quality, uniformity and esthetic appearance of turf in sports fields rely on mineral nutrient management, irrigation conditions, degree of soil compaction, pest and disease control, among others (Merino and Ansorena-Miner, 1998; Cockerham and Riechers, 1999). Nutrient and water requirements for a soccer field turf are highly variable and need to be evaluated to manage the appropriate frequency of mowing. Ordinarily, prior to games, soccer field turf should be mowed to maintain the appropriate height (in spring and summer up to five times per week). Therefore, the nutrients that make up the leaves and stems would have to be eliminated every time mowing is conducted. Since the trend of the turf grass is to continue growing, more nutrients and water would be required in a continuous mode to support healthy growth. Therefore, the question concerns to the extent of nutrients and water that should be supplied to the turf grass as well as to the frequency. Nutrient requirements of a typical plant are defined as the quantity of nutrients to satisfy plant metabolic needs for a healthy growth cycle. Nutrient requirements are evaluated as a function of dry matter produced and based on plant internal requirements, namely optimal nutrient concentration (ONC) of biomass at the time of mowing. The ONC needed for a healthy plant biomass growth is a parameter not yet clearly defined for all plants. An appropriate methodology to evaluate ONC relies on the concept of mass balance, which is based on the number of mineral nutrients a plant needs to subsist. Plant dry matter is made up of 16 essential mineral nutrients, of which only 13 are absorbed directly from soil. Therefore, if total dry matter during the whole plant growth cycle is 129 Proc. IS on Soilless Culture and Hydroponics Eds.: A. Rodrìguez-Delfín and P.F. Martínez Acta Hort. 843, ISHS 2009