Cultivating New Ideas For Your Growing Business
     
Home  
About Us  
 Scouting Notes  
Variable Rate Technology  
Crop Nutrients  
Seed  
Nutrient Management Plans  
Community Lawn Care  
 AgVentures Employees  

Links

 
 
Variable Rate Technology Information
Variable Rate Technology (VRT) is a new tool in the toolbox to help producers put fertilizer and lime where it belongs. 

How does VRT work?

      1.  Soil samples must be taken of a field using a GPS receiver to mark the points of the sample.       Samples are taken in 2.5 or 5 acre grid samples.

  2.  Soil samples are sent to the lab. Once the results come back, the soil samples are reviewed.  If there is a lot of variance in the field,  the field is eligible to spread using our Variable Rate Spreader.

3.  Once the go ahead has been given to spread variable rate, spreading maps are made.  Spreading maps are a colorful picture of what the field looks like.  It combines the information from the soil test results and the points of where the soil samples were taken to create a map of how to spread the field.

4.  Once the maps have been made, an agronomist checks the information to make sure it is correct and the material is loaded in to the computer on the spreading machine.

5. The spreader truck has a GPS receiver on it, and as the truck drives through the field the information on the card is being read and telling the truck how much fertilizer or lime to put out in an area.

Currently, phosphorus, potassium, and lime are being spread using the variable rate technology.

Below is an example of the Variable Rate Technology.

Potassium Soil Test Results

Red<100ppm, Yellow 100-130ppm, Green 130-165ppm, Blue 165-215ppm, Purple >215ppm

From the maps above we can then make spread recommendations maps.  After reviewing the recommendations we then can create a spreading file that our spreader trucks can read. 

Application Zone Acres lbs/Acre
Zone 1 - White 5.3 0
Zone 2 - White/Gray 1.5 265
Zone 3 -  Gray 9.7 514
Zone 4 - Dark Gray 6.9 655
Zone 5 - Black 9.4 741

After downloading the spreading file onto a little disk, we insert it into one of our spreader truck GPS system.  The spreader truck reads the file and GPS coordinates as it goes through the field.  As the truck travels the computer automatically changes the spreading rate according to the spreading recommendation file that was inserted into the system.  

 


Photo of the Viper System in our GVM Truck Spreader  

VRT can save you the producer money in many different forms.  VRT has the potential to apply fertilizer and lime in the exact amounts needed by the soil, thus this could lower your input bill.  Also by placing the amounts in proper amounts in the right spot on your fields you increase your yield potential, thus adding more to your bottom line.  Below are examples of a lime and phosphate situation. 

VRT Lime Application

Cost comparison:

VRT is a great technology to have, but it may not always save you money.  VRT does put fertilizer and lime where it is needed the following is an example of blanket speading (normal spreading) vs. VRT spreading a field.

Field Acres 65              
Field pH 6.2              
Fertilizer     Cost/ton $377.00              
               
Blanket Spreading Cost     Total Cost   Variable Rate Application Cost   Total Cost
  $/Acre         $/Acre    
Soil Samples (1sample/5ac) $2.50   $162.50   Grid-Soil Sampled (5 ac grid) $2.50   $162.50
($12.50/sample-if we sample)         Spread Files $50.00/file   $50
Spreading Application/ac $3.50   $227.50   Spreading Application-Fert. $5.00   $325.00
                 
          Fert      
Fert. rate/acre 200 lbs     Total Pounds Recommended 6300 lbs  
          From Spread File      
Total Cost of Fertilizer     $2450.50   Total Cost of Fert     $1187.55
                 
Total Cost of Fert. & Spreading   $2,678.00   Total Cost of Fert. & Spreading   $1,512.55
(Total cost of fertilizer+ spreading)       (Total cost of fertilizer + spreading)    
                 
Lime         Lime      
Lime and spreading $27.00 ac     Total Tons Recommended 142.4    
Tons of Lime applied/acre 2.5       From Spread File      
Total Cost per acre to lime $67.50       Spreading Cost $8 / ac $520.00
          Lime $20.00 /ton $2,848.00
Total Cost to Spread Lime   $4,387.50   Total Cost to Spread Lime   $3,368.00
(total cost per acre x acres)         (Spreading cost x acres) + (Lime cost x amount of lime)  
                 
Overall Cost     $7228.00   Overall Cost     $5,093.05
(Total of lime + total of fertilizer + soil sampling)       (Total of lime +total of fertilizer + grid sampling + spread files)
               
               
Difference $2134.95              
(Blanket spreading - VRT)                
               
Conclusion:                
In both cases (lime and fertilizer) the grower saved money by grid-sampling, because the soil samples showed 
that they did not need any fertilizer added to the field, the one year.  One thing we do need to remember,   
is that we do need to take in account for crop removal of potash and phosphorus.  In the follow year,   
the grower my have to replenish the soil with what they removed from it.        

 

Contact your agronomist for more information on how VRT can be an added tool to your crop growing needs. 

Hit Counter