A Cover Crop Program for Florida Pecan Orchards 41

and produce heavier quantities of green manure to be returned.
The hairy vetch in Fig. 18 made a good growth on Coxville soil
in Bradford County, and a
mixture of hairy vetch and
Austrian peas growing on
Bladen fine sandy loam in
a Duval County orchard is
shown in Fig. 19. Figure 20 i
20 shows Austrian peas I
growing on Norfolk soil in
the pecan variety orchard
on the Experiment Station
Farm at Gainesville. With
proper handling, therefore,
these winter legumes can
be successfully grown on
lands suited to pecans
throughout northern and
western Florida.
 The fertilizing program
could be one similar to that
practiced in this experiment
which would consist of 200 Fig. 18.-Hairy vetch growing on
to 300 pounds of 16% Coxville soils in a Bradford County
 to 300 ipoaunds of 16 pecan orchard.
superphosphate and 50 to
60 pounds of sulfate of potash per acre applied broadcast to the
soil just before the winter cover crop seed are planted. Some
suitable form of ammonia such as sulfate of ammonia or nitrate
of soda can be applied during June and July at the rate of 5 to
20 pounds per tree, depending upon size, or about 1/1 to 1/ pound
for each inch of circumference of the tree trunk. However, if
summer cover crops only are being grown, either with or with-
out inter-crops, then it is recommended that a general fertilizing
program be followed, such as outlined in Florida Experiment
Station Bul. 270, and supplemented with summer applications
of nitrogenous materials when advisable.
 Several important facts apparently have been emphasized by
the cover crop experiment reported on in this bulletin. First,
a soil condition suitable to pecan tree growth must be main-
tained, otherwise full benefit of commercial fertilizers will not
be obtained. Second, under conditions of soils and trees which
prevailed in the orchard worked with, appreciable increases in
nut production were obtained with sulfate of ammonia applied