How Much Fertilizer Per Acre for Hay?

How much fertilizer per acre of hay? My friend who is about to fertilize hayfield wants to know about the quantity and has literally been asking everyone. As he has purchased a pair of Mustangs for which he is developing a pasture. I, a proud owner of a lush hayfield of 10 acres, decided to help him with his grazing area.

Many farmers do not know the ideal quantity or when to stop, they either get stuck between too little or too much. I have seen many farmers fertilizing the soil with no defined quantity which has resulted in adverse outcomes. In my earlier years of fertilizing hay fields, I, too, got the quantity wrong many times. However, as they say, you learn from the mistakes, I took a lesson from it and researched thoroughly on the subject.

Hay and pasture do not receive the same level of care as some other crops. A low level of fertilizer management affects forage production and quantity. The productivity of hay and pasture fields can be boosted with good fertilizing techniques. 

Since most farmers were seen asking expert opinions online, I took it upon myself to write a comprehensive guide to put all the questions to rest, once and for all. You will leave from here with all your questions answered and ready to improve pasture and hay production for the feed. 

How Much Fertilizer Per Acre Of Hay?

Hayland grass and pasture need a good fertilization program for optimal economic production. Just as fertilizer stimulates the growth of other crops, it works magic for hay as well. 

Forages need essential nutrients to maximize the productivity and quality of the final products. Treating hayfields with the same fertilizer amount as other crops would not be wise as the amount of fertilizer used depends on the type of grass and soil fertility conditions.

Learn more about how you can choose best grass seed for pasture?

The essential macronutrients like Nitrogen, Phosphorus, and Potassium and some micronutrients like Boron and Sulfur play a vital role in dry matter production.

Make sure the fertilizer has the growth-stimulating macro and micronutrients to maximize yield.

According to research, One of the reasons for fertilizing hayfields is to increase the density and vigor of grasses to facilitate more livestock. 


For Nitrogen-deficient land, it would be foolish to expect tons of growth without applying the fertilizer. Just with the addition of Nitrogen fertilizer, see the yield multiply of a low-productive field. 

When the hay loses color and becomes light green, it is an indicator that the soil lacks Nitrogen. Apply a Nitrogen-rich fertilizer to treat Nitrogen deficiency.

If you expect a 2 or 3 tons yield, apply 60 lbs and 90 lbs Nitrogen fertilizer per acre of hay, respectively. 

If you want an expected yield of 4 and 5 tons, increase the amount of Nitrogen fertilizer to 120 lbs and 150 lbs per acre, respectively. (source)

It’s just not the fertilizer that affects productivity, to get an impressive yield of over 4 tons, the soil must have good water holding capabilities intensive management practices, like rotational grazing.


The second essential ingredient is Phosphorus. It helps with the growth and plant health in a different way than Nitrogen. Holds an important place in the NPK fertilizer, the soil should be given a dose if it’s phosphorus-deficient.

12 to 15 pounds of phosphorus is removed when cutting or grazing each ton of ton hayland, therefore, the soil needs a constant Phosphorus supply to make up for the amount lost.

The recommended amount of Phosphorus is 60 lbs per acre, increase the amount if you want a greater expected yield. 



Each time the field is cut or grazed, around 55 to 60 pounds of potassium gets removed along with it. Therefore, fertilize the land with Potassium to keep a balanced nutrients profile.

For 2 or 3 tons, apply 40 lbs and 50 lbs of P2O5 respectively. For 4 tons of dry matter production per acre, spread 60 lbs of Potash fertilizer over the land. For over 5 tons yield, increase the fertilizer application to 70 lbs of P2O5 per acre. 

Sulfur & Boron

Some crops can do without Sulfur and Boron but pasture and hay need a sufficient supply of these two micro-nutrients to optimize yield. 

Around 5 lbs of Sulfur is removed annually when a single ton of hayfield is grazed. Just apply about the same fertilizer as the amount was lost during grazing.

If the soil test for boron deficiency comes positive, apply about 2 pounds of Boron fertilizer per acre every three years. For sandy soils, around 0.5 to 1 lbs would be sufficient.

To fertilize hay, pick an NPK fertilizer with a good amount of all the essential three macro-nutrient. It will save you the trouble of buying each essential nutrients fertilizer separately.

Soil Test

Soil testing will spare you the guesswork. It should not be overlooked as it is the only way to know the fertility status of the soil and what kind of fertilizer you should be applying. Farmers often do not conduct soil testing for hayfields as it is deemed a 

low-value crop

Soil testing done with proper kits informs about the soil condition, texture, and deficiency of any essential ingredients. It also clarifies the availability of phosphorus, potassium, nitrogen, and other micro-nutrients in the soil.

Soil tests help identify the area with low or high fertility and nutrients levels. So, once the results come, apply the nutrients accordingly. Do not overdo it as excessive nutrients levels can also be a problem. The amount of fertilizer given above may not be relevant anymore considering the current status of nutrients.

When To Apply Fertilizer?

Hayfields should be fertilized at a certain time, not when you want to. Cool-season grasses respond well when fertilized in the late spring. 

Warm-season grasses thrive in mid-summer, so, the ideal timing for fertilizer application would be late spring.

In brief, expected hay yield does not ride on just fertilizer alone, count factors like intended use, soil texture, fertility, and management intensity to contribute to the desired outcome. However, fertilizing the right amount at the right time does make a world of difference. 

Read more about Why are Hay Bales Left in Fields? 

Hi, I am Waqar and active in the horse world since 2012. I have MSc (Hons) in Agriculture from the University of Agriculture Faisalabad. I love to solve equine health care issues and note down in the form of research papers. I have written hundreds of equine health care, accessories, names, and history-related blogs. My equine related work is watering a lot of horse-related magazines and blogs.

Leave a Comment