The Rural Voice, 1981-06, Page 29Sludge source
of nutrients
H.CLand
Soils and Crops Branch
O. M. A. F.
Stabilized sewage sludges, the black
liquid produced in municipal sewage
treatment plants, is a rich source of
nitrogen and phosphorus - two plant
nutrients often needed in agricultural
soils. Sewage sludge contains up to 11%
solids which are an excellent source of
soil -building organic matter. On the other
hand. many other nutrients found in
sewage sludge are needed in very small
amounts. or are not needed at all by
agricultural crops.
Joint guidelines are developed by the
Ministries of the Environment, Health
and Agriculture and Food to control the
spreading of sewage sludge on agricult-
ural soils and ensure that agriculture and
the environment are protected. In these
guidelines the Ministry of the Environ-
ment:
(a) licences haulers and spreading sites
(b) provides sewage sludge analysis
(c) and calculates and monitors the
spreading rate.
Not all soils are suitable for the
spreading of sewage sludge. It should be
spread on mineral soils only. Farmers can
apply to use sewage sludge at the
regional Ministry of the Environment
office. Detailed information on the field in
question including a recent soil test, must
be provided. Only fields with a pH higher
than 6.0 and a phosphorus soil test
reading lower than 60 will be considered.
The rate of application of sewage
sludge is based on the nitrogen need of
the crop and the available nitrogen to
metal ratio in the sludge. For example, no
more than 135 kg/ha of available nitrogen
can be applied to a corn field once in five
years. Lesser amounts should be applied
to cereal crop fields to avoid lodging
problems. If the ratio of available
nitrogen to metals is too low the rate of
application can be adjusted accordingly.
Unacceptable sludges must be disposed
of in land fill sites or incinerated.
Sludge should be handled in the field
the same way as manure. It should be
ADVICE ON FARMING
applied to field crops such as corn, mixed
hay or cereals because they can use the
nitrogen. The sludge should not be
spread on wet fields or during rain
because of soil compaction and runoff
problems. Sludge should be worked into
the soil immediately to conserve nitro-
gen.
Fuel meter
undergoes tests
A Kemptville College of Agricultural"
Technology engineer is working on a fuel
efficiency meter that may help farmers
get more for their fuel dollar.
Dr. John Clark, head of the college's
engineering section, developed the meter
a year ago and is ready to test it in the
field this summer.
"The tractor performance meter is a
pre-programmed control unit about 15
cubic centimetres (6 cubic inches) that
compares the amount of power output of
the tractor and the amount of fuel
consumed," he sayd. "By combining the
forward speed, implement load and fuel
consumption, the micro computer pre-
sents a fuel efficiency index."
The digital display fixed to the top of
the tractor looks like a digital clock
showing from 1 to 100. When the tractor
is operating efficiently, the number
shown ranges between 60 and 100. At
optimum efficiency, most tractors would
show a reading of 80.
Over the years, tractor operators learn
which speeds obtain maximum fuel
efficiency," says Dr. Clark, "but it takes
a lot of experience. Using this meter,
novice tractor operators could learn
quickly how to drive a tractor for best fuel
economy."
"There's nothing similar to this meter
available now," says Dr. Clark. "In light
of increasing energy costs, this meter
could be valuable to any farmer who
wants up to the minute information to
help achieve the best fuel economy."
The test fuel efficiency meter is
programmed only to provide a fuel
efficiency index, but with slight re-
programming the unit could provide
other valuable information. For example,
Dr. Clark says the unit could show the
farmer how many hectares have been
covered, how much fuel had been used,
and speed.
MAILBOX OF THE MONTH
This month's mailbox belongs to Bob and Mildred Ulch.
Located in Fullarton Twp. [Photo by Keith Butson]
THE RURAL VOICE/JUNE 1981 PG. 27