Florida Agricultural Experiment Station


pet grass did not respond to heavy applications of superphos-
phate, potash and lime (Table 4). It is thus apparent that
carpet grass is stimulated primarily by nitrogen and that light
applications of lime, superphosphate and potash along with nitro-
gen are satisfactory.
 The effect of liming and fertilization on the mineral content
of carpet grass grown on a Bladen fine sand is shown in Fig. 16.
When it was treated with nitrogen alone, the phosphorus, cal-
cium and potassium contents were lower than in unfertilized
grass. The carpet grass treated with a mixture of minerals
(lime, nitrogen, phosphorus and potash) was 61 percent higher
in calcium, 75 percent higher in phosphorus and 24 percent
higher in potassium than unfertilized grass.
 Since nitrogen was found to be the most effective element for
increasing growth of established carpet grass on mineral soils,
an experiment with 4 sources of nitrogen was started on a carpet
grass sod near Gainesville in 1938. The sources of nitrogen-
nitrate of soda, sulfate of ammonia, uramon, and calcium cyana-
mide-were used with mixtures of lime, superphosphate and
potash and with superphosphate and potash (Table 5). This
test again shows that growth was increased primarily by nitro-
gen. All 4 sources of nitrogen increased growth greatly. High-

1100 2.
 000 2.0


 goo (1
 S 1.9
 1.7
 800 0 .6
 1.5





 i B 0.3
 2 00 0.4








 o Fertilizer. N i s0rc appI d aoally. 3b# N, 36# P20, 12# R20 "d


 Chart shows effect of fertilization on early season (April 17 to May 28)
 yield and chemical composition of carpet grass, 1940. Bladen fine sand in
 Duval County.
 Duval County.