The Rural Voice, 2003-12, Page 23root system will take up the ammonia
sooner before or during its
conversion to nitrates.
Nitrogen is susceptible to leaching
in its nitrate form while ammonia
doesn't because it is positively
charged and adheres to negatively -
charged soil colloids. Negatively -
charged nitrate molecules move
easily into ground water.
High levels of nitrate in water
have been shown to cause "blue
baby" syndrome and may cause
stomach cancer, Coelho said so
reduction of nitrogen loss through
leaching is an advantage of
implementing a high ammonia diet
for crops.
Leaching is generally greatest in
fall and spring when most
drainage occurs, especially if
more nitrogen has been applied than
the crop could take up. Planting a
cover crop like cereal rye in the fall
can improve nitrogen use with
leftover nitrogen sequestered in the
rye until the next growing season.
Winter rye works well because it
continues to absorb nitrogen even in
cold weather. Even a cover crop isn't
enough to absorb high amounts of
manure applied in fall on sandy soils,
Coelho said. Uptake of the plant is
limited under these circumstances
and the nitrate leaches rapidly
through the sand to the groundwater.
In heavy textured soil nitrogen that is
applied late will be conserved in the
soil if the winter is cold, but if there
is a wet, mild winter some of the
nitrogen is lost. If liquid manure is
applied pre -crop on light soils it can
leach during the growing season so a
split application — a lighter
application preplant and a side -
dressing later — will help avoid
leaching.
There are problems with run-off
(across the surface of the soil) and
run -under through drainage tiles. In
porous soils where there is a high
application rate or in swelling clay
soils that are dry and cracked at the
time of application, there can be
direct movement of nitrogen into the
tile drains.
While leaching is a problem for
nitrogen, it's rare in phosphurus
which is tied up with other soil
minerals and organic matter.
Phosphorus in liquid hog manure is
mostly inorganic phosphate with 40-
60 per cent available to the plant in
May Christmas Fill
Your Home With Joy
Warm Holiday Greetings
from Mark Harding & Staff
rtta .c BUILDERS LTD.
Harriston, Ontario 519-338-2111
DECEMBER 2003 19
Holiday Greetings
/i
rt A $
.1:‘4N`1 ' `te �r :: t. .." ' /> Y!_1.
1A A.&d� •� ,VI ---
May you enjoy the richness of our heritage with friends and
family this special season and throughout the coming year
GERMANIA FARMER'S
MUTUAL FIRE INSURANCE
rirliA Ayton Ont. NOG 100 519-665-7715
May Christmas Fill
Your Home With Joy
Warm Holiday Greetings
from Mark Harding & Staff
rtta .c BUILDERS LTD.
Harriston, Ontario 519-338-2111
DECEMBER 2003 19