This study was carried out in the open Experimental Field of the Ornamental
Horticulture Department, Faculty of Agriculture, Cairo University, Giza, during the two
successive seasons of 1996/1997 and 1997/1998, with the aim of investigating the
effect of soil moisture content [irrigation when soil moisture content reached 30, 50 or
70% offield capacity (F_C_)], and N fertilization levels [0, 5,10 or 15 gm N/m2, applied
monthly using ammonium sulphate (20-5'% N)] on the vegetative growth and chemical
composition of Bermudagrass (Cynodon dacty/on L.) plants. At each irrigation, the
plants were watered with 251itres of tap water/m" The following results could be obtained: Irrigation when the soil moisture content reaches 70% F_C_, combined with
application of a relatively high N fertilization rate (15 g N/m²), resulted in the most
vigorous vegetative growth (in terms of plant height, as well as the fresh and dry
weight of clippinqs). However, turf.colour was more sensitive to the N rate than to the
soil moisture level (within the tested range of soil moisture levels), since the best
colour (l.e. the highest leaf pigments content) was obtained with fertilization using a
moderate N rate (10 g/m²), regardless of the soil moisture level. Increasing the soil
moisture content caused a steady reduction in the soluble sugars content, but
increased the insoluble ones in the clippings. Also, the contents of soluble sugars,
insoluble sugars and total carbohydrates were steadily increased by raising the N
fertilization rate, with the highest N rate (15 g/m2) giving the highest values. In most
cases, the highest contents of nutrients (N, P and K) were obtained from plants
fertilized with the medium N rate (10 g/m²). The effect of soil moisture on the nutrients
content differed from one nutrient to another, since the highest mean concentrations
of N, P and K were obtained with irrigation at 30%, 70% and 50% F.C., respectively.