-: Okay, your calculations, hopefully you're done.
You've had some help if you've needed it
and now we'll go through what the answers are.
So, what is the value
for that first year without incorporation?
We need to calculate both the ammonia and the organic.
We do that separately
and this is a very easy one
'cause you have to multiply it by zero.
If you don't incorporate, you lose all that ammonia,
it goes up in the air.
So, we really need to only be concerned
with the organic N
and here we had 16.4 pounds
and we had availability factor of .25,
so that works out to 82 pounds.
Since there's no ammonia N,
the total available this year is 82 pounds.
Now, if we incorporated immediately,
we have a different situation.
We have almost 100% of that is conserved, 95%,
so we get 91 more pounds
by incorporating right away.
The organic N is the same.
We get the same 82 pounds
regardless of whether it's incorporated or not.
So, if you add those together,
these two examples, there's 90 pounds difference
at 50 cents a pound of nitrogen,
that's a $45 per acre difference in value
of that manure.
So, if you can incorporate it,
it saves you some money.
Now, if you're in a highly erodible situation
and you can't do the tillage,
you have to take that into account.
So, what's the answer to the following year?
The first part of the question might be
if we don't incorporate it in the first year
and again, it doesn't really matter
in the second year, all the ammonia is gone,
so it doesn't matter whether we incorporate or not
in the first year
and so, we use that .15 figure
and we come up with 49 pounds available,
almost 50 pounds.
Again, if you don't take this into account,
at 50 cents a pound of nitrogen,
you're losing $25 an acre in lost nitrogen.
It's still there
but you're probably putting on fertilizer and nitrogen
that you didn't need.
If you incorporated it the first year,
you get the same exact answer
'cause again, ammonia N doesn't make any difference
going into the second year.
Now, before we finish this section,
we just want to make one little warning
or a couple of warnings about his.
When we do the calculations pre-season,
it's just an estimate, we're guessing.
We could be off in either direction.
We think that our availability factors are conservative.
In other words, we are saying that the availability is lower
than what it actually is, so if we say 25%,
it's probably 30 or 35%.
So, you don't have to build in anything for safety
because our figures already have that in.
It depends on the moisture and the temperature
during the season.
During hot, dry years,
you probably not gonna get as much
as during years where the temperatures are normal
and we get good rainfall once a week
or something like that.
The best way to handle this
is to do some kind of in-season testing
with a chloroform eater or a sensor
or some way to assess
if the crop needs more nitrogen or not.