The Rural Voice, 2001-07, Page 48L
Research Scrap Book
Researchers explore E. coli and the soil
A team of University of Guelph
researchers are in the first year of a
three-year project to examine factors
that cause E. coli bacteria to penetrate
the soil and enter the drinking water
supply after manure applications.
The team, headed by Land
Resource Prof. Mike Goss and includ-
ing Prof. Hung Lee of Environmental
Biology, Prof. Gary Parkin of Land
Resource Science, Prof. Hugh Whitely
from Engineering, Prof. Jeff Wilson of
Population Medicine and graduate
student Adrian Unc, note that a third
of all wells in Ontario are contamin-
ated with E. coli, though not
necessarily the pathogenic strain E.
coli 0157:H7. Of chronically contam-
inated wells in Ontario, 20 per cent
are estimated to have been polluted by
farm and wild animal manure.
Various strains of E. coli are found
in all types of manure. Their presence
in drinking water has been shown to
be a good indicator that other
microbes, which can cause sickness,
may also be present. However, the
lethal strain of E. coli 0157:H7 is
found only in cattle, sheep and goat
feces and in some wild species such as
deer.
Soil characteristics such as texture
and pH, can influence bacterial
penetration in soil, while organic
material in manure can block pores
and halt the infiltration of rainwater.
Goss and his team are also
comparing solid and liquid manure
applications to determine which type
has a greater impact in promoting soil
penetration by bacteria.
Soil layers may give natural
protection to groundwater, or
conversely, promote the movement of
bacteria into the ground, where it can
lead to water contamination. The team
is now employing water partition
models to see how manure and soil
characteristics interact to affect the
dominant pathway of water flow over
the land surface or through the layers
of earth and rock.
Salt content in manure may also be
a significant factor influencing bact-
erial movement. One unusual charact-
eristic of bacterial cells is that they
can change the electrical charge on
their surface. The charge on E. coli is
determined by the electrolytic pro-
perties (i.e. the electrical effects of the
solution on objects, surrounded by it)
of the solution in which the bacteria is
located. This is dependent on the salt
concentration. Manure contains
enough ions to change the electrolytic
properties of the soil, and thus change
the charge on the E. coli as well.
If the net charges on the bacterium
and the soil are similar, the bacterium
is less likely to be retained on the soil,
thereby moving rapidly with the water
infiltrating into wells and ground-
water. If the net charges on the bact-
erium and soil are sufficiently
different, the bacterium will be held
back on soil particles and are more
likely to die before they can reach a
well.°
— Source: University of Guelph
Agrifood Research Magazine
Tractor autopilot unveiled at show
Want to catch up on some phone calls while riding down the field seeding,
spraying or cultivating with your tractor? The new Trimble AgGPS autopilot
system, unveiled at the Western Canada Farm Progress Show, will automatically
steer a tractor to within inches for all farming applications.
The system connects to the tractor's power steering hydraulic system to auto-
matically steer it in straight paths, pass after pass. A field computer inside the
cab allows the operator to select field patterns and display operating parameters.
A lightbar is used to guide the operator on path at the beginning of a pass. Once
on a swath, the driver engages the autopilot system to perform and oversee field
operations. For safety, the operator can disengage the system simply by moving
the steering wheel.
At the heart of the system is the high-performance Trimble AgGPS
Navigation controller. Attached to the controller is an AgGPS 214 Real -Time
Kinematic receiver, in -cab terminal, lightbar, and a remote display and logger. 0
— Source: Western Canada Farm Progress Show press release
44 THE RURAL VOICE
CD provides world
of info for hog
producers
A new software package called
Reproductive Management of Pigs
can bring pork producers 1,400
pages of advice from experts from
Australia, the United States, the
United Kingdom and Canada on a
series of CDs that run on either PC
or Macintosh computers.
The program lets the user
identify the problem and invest-
igate possible sources. The "Solv-
ing Known Problems" section
guides the user through a menu of
choices that provide possible
solutions and cross references with
more information in a step-by-step
process that is easy to navigate.
The software shines in the
"Identifying and Solving Known
Problems" section. The producer
may know that herd production is
down, but may not know why. The
software guides the producer
through a herd diagnosis process
that begins by asking questions.
The "decision tree" might work
something like this: if a problem
suspected in sows and weaning is
taking place at less than three
weeks of age; and less than 23.9
pigs are weaned by sows annually;
and the average litter size is 9.8
pigs; with a preweaning mortality
of 10 per cent or more; then eight
possible outcomes are presented
with 33 separate solutions.
There are also guides to herd
breeding management, which deals
with long-term development
issues. The guides provide inform-
ation for all stages of pig develop-
ment and information based on
clinical data in the databases.
Topics include: gilts from
selection to puberty and first
mating; mating, including estrus
detections, timing, frequency,
insemination and natural
techniques; boars from libido
issues to semen collection and
processing; pregnancy issues;
farrowing issues; lactation and
weaning; culling and more.0
— Source: Western Producer