IPM/A -9-

Periodic soil fertility tests should be used to deter-
mine whether or not Supplementary chemical fertilizers
are needed to augment compost.

In areas of turf with heavy weed growth, spring or fall
applications of soluable forms of nitrogen together with
grass seeds on a Spot-treatment basis May reduce weed
growth. This is due to the fact that grasses are better
able to grow in fertile soil than are most weed

spectes.

E. Allow turf to grow as “high” as possible to
maximize the ability of grasses to shade out weeds. It
is recommended that the city experiment Mowing some
Fields at 21 to 3 inches. The increased shading pro-
vided by grasses at these heights changes the microcli-
mate at the soil level and makes weed growth more
difficult. Raising the mowing ‘height also allows the
grass blades to develop increased area for photosynthe-~
sis. which in turn increases grass vigor and tolerance to

wear.

7 Fe. On fields with irrigation systems, it is recommended
that _a_tensiometer (moisture meter) be used as an aid in
determining when to irrigate and how much water to
apply. In general, turf should be irrigated sufficiently
to saturate the soil to a depth of six inches. The next
irrigation should occur when the top one-half inch of
soi? has dried out. Grasses grow most vigorousiy when
adequate soil moisture is available. Under conditions

TSN Na ate WE Een ace WE Mf beasarne eee