How To Calculate Fertilizer Application Rates Per Acre

Whether you have a home garden or land for hay and forage crops, the expense of fertilizer is often undermined. People are most likely to focus on the planting and watering expenses and don’t think much about the compost.

fertilizer application rates

Sadly, it doesn’t bring any goodness to the plants and crops. On the contrary, using the proper amount of fertilizer per acre will not only keep the plants healthy but also yield more crops. Also, it reduces unnecessary expenses.

So, you must know how to calculate fertilizer application rates per acre.

Since the calculation is a complex one and needs the involvement of some mathematics, you might find it a bit challenging. So, we have compiled the simplest method to calculate the fertilizer application rate.

So, shall we start?

How To Calculate Fertilizer Application Rates Per Acre

When it comes to applying fertilizer for the lawns or gardens, the underlying problem lies with the determination of fertilizer needed per acre. It is crucial since it will control the amount of different nutrients for the pants, such as Nitrogen, phosphorous, and so on.

The process of fertilizer application rates is somewhat like this:

Step 1: Understanding the Labels on the Bag.

Before you can use the fertilizer calculation formula to determine how much fertilizer you will need to purchase, you should understand the percentage (%) rating written on the fertilizer bag.

It means you need to divide the total amount of fertilizer with 100 and then multiply the result with the total weight of the bag. This way, you can find the exact amount of the nutrients in the fertilizer bag.

For instance, suppose a bag is labeled 46% N and 15% P and 39% others. Also, the fertilizer weight is 50 pounds.

So, to know how much Nitrogen, phosphorus, and other nutrients it has, divide each number with 100. So, we get the following results.

For Nitrogen, 44/100=0.44.

And for phosphorus, 15/100=0.15 and other nutrients 39/100=0.39.

Now, multiply the number with the fertilizer weight. For this bag, it is 50 pounds. So, the amount of Nitrogen the particular fertilizer has is:

0.44X50=22 pounds

For phosphorus, 0.15X50=7.5 pounds, and lastly…

For other nutrients, 0.39X50=19.5 pounds.

Once you know how much of what nutrient bag has, we might move to the next step.

Step 2: Finding the Recommendation for Essential Fertilizer Per Acre

At this moment, you will have to find the recommended amount of fertilizer for each acre for various plants and crops. As you know it, you can quickly determine how much fertilizer you would need for each acre.

Step 3: Determining the Area You Will Need to Fertilize

As part of your lawn fertilizer calculator, now you should calculate the total land area of the lawn. Then you can convert it to acre measurement and step to the last step of calculating the fertilizer cost for the yard or garden.

The land calculation is straightforward. Use a measuring tape to find the length and width of the space. Multiple them and then divide the result by 4840 square yards to get the numbers in an acre.

For instance, if you have a garden with a maximum length of 200 yards and a width of 300 yards, the garden area will be:

200X300=60000 square yards.

Then, divide it with the 1 acre (4840 square yards). The result will be:

60000/4840=12.396 acre.

However, sometimes you might measure the area in foot and meter units. In this case, the acre measurement is slightly different.  For this, the per acre land measurement is:

One acre = 4840 square yards.

1 acre = 43560 square feet.

1 acre = 4046.8564 square meters.

Step 4: Fertilizer Calculator Per Acre

Now, it’s time to find the exact amount of fertilizer you will need for each acre. Let’s proceed with an ingenious example.

We have already taken a fertilizer bag that consists of 22 pounds of Nitrogen and 7.5 pounds of phosphorus. Also, it has other essential elements, such as phosphate of around 19.5 pounds.

Supposes, the fertilizer manufacturer recommends using 7 pounds of Nitrogen for the garden. So, the total amount of fertilizer you will need:

7X12.396=86.772 pounds of Nitrogen.

However, each bag consists of 22 pounds of Nitrogen, right?

Now, divide the total required amount of Nitrogen for the garden by the amount it comes in a bag.

The formula will be:

The total amount of required fertilizer/ Weight of Nitrogen per bag= Exact number of fertilizer bags you will need.

The result will be somewhat like this-

86.772 pounds/ 22 pounds= 3.94 bags of fertilizer.

It speaks that you will need approximately four bags of fertilizer bags if the container has 22 pounds of Nitrogen in it.

So, the total costing formulation will be like the following-

Fertilizer pounds per acre calculator= (Total area X Required fertilizer recommendation)/ Amount of fertilizer per bag.

You can determine the amount of phosphorus, phosphate, or other nutrients required for the garden or lawn with a similar formula.

The Bottom Line

Determining the required amount of different nutrients for each acre of land in the garden or lawn is no easy task. You will need to go through extensive calculating and a lengthy process.

However, the process described here should facilitate you with the meticulous calculation.

Here’s a quick recap of each step:

  • Calculating the amount of fertilizer weight in each bag
  • Calculating the total acre land of the lawn
  • Finding the fertilizer recommendation
  • Calculating the amount of fertilizer bag you will need
  • Calculating the final cost.

You can also choose for the online fertilizer pounds per acre calculator.

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