How much money can I make harvesting with selective mechanical asparagus
harvesting equipment?
WARNING! I am
not an accountant nor an asparagus grower... just an inventor.
This is just kind of a ballpark estimate...
Individual results may vary...
To get a rough idea of what it will cost you for
mechanical harvesting and to keep it simple, I am not messing with tax
implications, financing, etc. I will assume the machine is
purchased in cash and amortized over 10 years. The labor costs in $/hour
should include all labor costs. You know... the part you pay the
government. Figuring the Cost of
Mechanical Harvesting
I've put together a spreadsheet in Excel
that calculates the cost of harvest and the profit when using the
asparagus harvester. Scroll to the bottom of the page to see the
sample spreadsheets. If you would
like a copy of the excel spreadsheet to play with just send me a request
on the form at the bottom of my home page and I will email you one.
Be sure to put in your correct email address...
First I'll run through how the spreadsheet works and
provide more information about the inputs.
These are the inputs to the spreadsheet:
-
How many "cutting" days make up your
season.
-
How much you pay the tractor driver
in dollars per hour.
-
How much you pay the man sorting the
asparagus on the back of the machine in dollars per hour.
-
What the row spacing is... center to
center distance in inches.
-
How many hours per day you will be
running the machine.
-
How fast in mph you will run the
machine.
-
Your cost of fuel for the tractor
-
Your mpg while harvesting
The effects of the less obvious inputs
are:
-
Decreasing the number of cutting days
decreases the cost of harvest.
-
Increasing the center to center row
spacing reduces the cost of harvest.
-
Increasing the hours per day reduces
the cost of harvest.
-
Increasing the speed of the machine
reduces the cost of harvest.
Step 1. Determine the number of acres per
hour and acres per day the machine will harvest.
1 Acre = 43,560 sq. ft. = 208.7 ft. x 208.7 ft.
Divide 208.7 by the
center distance in feet to get the number of rows.
Multiply the number
of rows by 208.7 ft. and then divide by 5280 ft/mile to get miles/acre
Now divide the
speed in miles per hour by the miles per acre and multiply by 4 (rows)
to get the acres
per hour.
Multiply the number of hours per day you run the machine times the acres
per hour
to obtain the acres
per day that will be harvested.
Step 2. Labor costs.
Add the dollars per hour of the driver and the sorter/packer and
multiply by the number of
hours per day of
machine usage and then multiply by the number of cutting days in the
season. This gives
you the cost per cutting day.
Multiply the cost
per day times the number of cutting days per season and divide by the
total acres per day
to get the labor costs per acre.
Step 3. Fuel & Maintenance
Multiply the mpg (miles per gallon) times the acres/mile.
Divide 1 by the
result.
Multiply that
result times the acres per day, then multiply by the $ per gallon fuel
cost.
This gives you the
fuel costs per day. Multiply by the number of cutting days and
divide
by the acres/day to
obtain the fuel cost per acre per season.
For maintenance lets use $2,500 per season. Divide that by the number of
cutting days and
then divide by the
number of acres per day to obtain a per acre per season cost.
Step 4. Machine cost
Divide $125,000 dollars by 10 years then divide by the number of acres
per day. The result
is your $ per
acre to purchase the machine amortized with no interest over 10 years.
Step 5. Add them all up
Add the Labor costs per acre, Fuel & maintenance costs per acre, and the
machine cost
per acre to
get your total per acre harvesting costs.
Now you have a pretty good idea of what
your harvesting costs will be on a per acre basis and we can
select a recovery %.
Interesting Note: The crop
yield has no affect on the cost of harvesting per acre. Harvesting
costs are the same if you are recovering 100 pounds per acre or if you
are recovering 4,000 pound per acre. You are paying on a per acre basis
for the machine costs, fuel and maintenance, and you are paying the
labor hourly. However, the cost per pound would obviously change
dramatically, but for this exercise we are looking at costs per acre.
Selecting a % recovery figure
We do not know what the % recovery figure
will turn out to be with this machine. We were quite close to 60%
with our last prototype, but we've made dramatic improvements with the
design of the new machine building on what we learned in the last field
trials. We hope we end up between
75% and 80% but there are no guarantees. We have dramatically
reduced our spear sensing width from around 4 inches to about 2 inches
effectively doubling our sensing resolution. We've reduced the
blade width from 2-3/4 inches wide to 2 inches wide which will reduce
collateral damage to nearby spears.
Another much improved area is the air
cylinder operation when multiple cylinders are firing at once. On
previous models when several cylinders were moving at once there would
be a pressure drop in the supply lines and manifold that corresponded to
how many cylinders were operating. A change in pressure across the
cylinder ports causes a change in cylinder speed which affects the cut
timing. Our new machine utilizes
the large tool bar as the manifold for the cylinders. This
completely eliminates those pressure drops since every cylinder in
effect is connected directly to a tank. The tool bar is large enough to
consider it a tank for the amount of air we will be using. This will
improve the cut timing and should improve the % recovery yield.
The new cylinder design provides a reduced moving mass,
and with much better breathing the new cylinders will be a little faster
than the previous ones. Faster cylinders translate into being able
to harvest spears that are closer together when lined up in the same
sensing/cutting channel. In other words, you can go faster and/or reduce
collateral damage I believe that
over 70% is a solid prediction for the new model SP-2010 selective
asparagus harvester.
Keep in mind that there are a number of
factors that will affect the performance of the harvesting equipment
such as the variety of asparagus. Different varieties of asparagus
produce different densities of the crop (spacing between spears), spread
out at different rates, produce different sizes of spears etc.
Many of these factors can influence the machine percentage.
Soil conditions can also affect the percentage of
recovery as well as the weather. The spears can be more brittle
when cold and right after being rained on. The spears can grow at
dramatically different rates depending on the temperature. Wind
can cause the spears to lean and hook. Weeds can raise havoc with the
machine. Cost of Growing Asparagus
To be honest I'm not really clear on how
much it costs to grow asparagus. It seems to vary quite a bit.
I recently read somewhere that it costs about $1,000 an
acre for the costs not associated with harvesting.
I also have a copy of a U.C.
Cooperative Extension Circular 104-V 2002-03 that puts the non
harvesting expenses at $728.50/acre/year for years 2 and up. After
amortizing the first years expenses the figure comes to about
$1,000/acre.
The costs include fertilizer, herbicides,
irrigation, fungicides, insecticides etc. It looks pretty
comprehensive. I will use $1,000 per acre for my examples.
Market Price
I've seen prices all the way from around
$17 per crate to over $55 a crate (28 or 30 pound crate... not sure
which).
So now we simply take the market price in
$/pound and subtract from it the harvesting costs and the growing costs
which will leave the profit.
Calculating Your Profit
Multiply your expected yield in pounds/acre times the recovery
percentage to obtain your machine yield
in pounds/acre. Multiply that result
times the market price to get your gross revenue.
Next divide
the harvesting cost per acre figure by the number of acres per day to
get harvesting costs
per pound. Do the same for the
growing costs.
Now subtract the growing costs and harvesting costs from the market
price to get a profit per pound.
Multiply your profit per pound times
the machine yield in pounds per acre to obtain your profit per acre.
Scroll down to see the sample spreadsheets.
Supplemental Information
Machine Speed
The number of acres per day your machine
can harvest depends on the row spacing and the forward machine speed.
The model SP-2010 is technically capable of correct cut timing from less
than 1/4 mph to about 3-1/2 mph. We don't know what the top
harvesting speed is. The speed at which the harvester will be run
is determined by the spear density of the crop, field conditions, soil
conditions. Most of the harvesting
we did with our prototype was at about 1-1/2 mph, so we are very
confident that the machine will work fine at 1-1/2 mph to 1-3/4 mph, and
we are pretty sure it will run fine at 2mph -1-2/4 mph. Above that
who knows.
The stroke time for the air cylinders is
about 0.18 seconds. With the machine moving forward at 1mph the machine
moves forward about 3 inches. At 2mph the harvester moves forward 6
inches. The faster you go the more space you need between spears
that are lined up in the same channel on the bed. If you run the machine
too fast you will begin to miss spears because the cylinders won't be
able to cycle quickly enough. If
the furrows are not smooth the machine will bounce more and this will
cause depth of cut problems and increased potential for spear damage.
Row Spacing
The row spacing makes a big difference in
how many acres a day the machine will cover. A 4 row machine
traveling at 1.5 mph with a row center-to-center distance of 36 inches
will do about 2.18 acres per hour while the same machine at the same
speed with a 70 inch center-to-center distance will do 4.25 acres per
hour.
Working Hours
The number of hours per day has a
substantial impact. The more hours you run the machine per day the
more acres per day you cover and the lower the harvesting costs. The
Geiger Lund SP-2010 was designed to run 24 hours a day.
Labor Costs
I don't know what the actual costs are
these days, but I will use $15 per hour for the driver and $10 an hour
for the sorter.
Percentage Recovery
Obviously the percentage of the crop that
the machine is able to harvest is one of the more important numbers.
We know the machine will do 60%, but since we don't really know how
effective our improvements will be it's tough to make predictions.
Personally I think the machines will end up doing 70% to 75%. I
don't think 80% is out of the question.
Miscellaneous expenses
I have no idea what kind of mileage one
gets on a tractor pulling a 8,000 pound harvester over soil I know
nothing about and with the machine pulling about 10 - 15 horsepower off
the PTO shaft. My wild guess will
be 5 miles per gallon. Another
expense is paying for the fuel... diesel I would imagine. I have
no idea what farmers pay for fuel, so my wild guess for this will be
$3.00 per gallon. |