Trends in Fertilizer Use and Efficiency in the U.S.

By Henrique Monaco, Nick Paulson, and Gary Schnitkey

Fertilizer is one of the main inputs for crop production in the U.S., particularly for corn, wheat, and soybeans. While application rates per acre are increasing for some crops, yields are outgrowing application rates, resulting in increasing efficiency of use. This article examines long-term trends in fertilizer application rates and crop yields, discussing how fertilizer efficiency per unit of output has evolved for the three major crops in the U.S. with implications for demand.

Total Use Shares by Crop

According to the International Fertilizer Association the U.S. utilized about 14,900 thousand metric tons of nitrogen (ammonia), 4,600 thousand metric tons of Potassium Chloride and 6,500 thousand metric tons of phosphate for fertilizer in 2022 (International Fertilizer Association, TEAD Analysis). The majority of fertilizers used for crop production in the U.S. are applied to corn, wheat, and soybeans. USDA survey data suggests that fertilizers used for these crops have accounted for 92%, 94% and 95% of total applications of nitrogen (N), phosphate (P), and potassium (K), respectively, since 2002[1] (National Agriculture Statistics Service (NASS) Agricultural Chemical Use Program).

Figure 1 shows estimated shares of fertilizer use by crop for each major nutrient. Corn, given its large U.S. acreage, is the largest user of all three nutrients (78% of nitrogen fertilizer, 54% of P, and 53% of K). Wheat is the second largest user of nitrogen fertilizers. Soybean, as a legume, is able to fix the majority of their nitrogen needs which limits the amount of N fertilizers applied reflecting the lower share of use. Soybean acres use the second largest shares of total P and K.

Trends in Applications per Acre

Total demand for fertilizers are impacted by planted acres to crops. Planted acreage to major crops has stabilized in recent years, though some substitution between crops has occurred (Farmdoc Daily, April 2, 2025).

Application rates per acre are illustrated in Figure 2 for the major crops and nutrient types. The dots represent observed USDA survey responses while the dashed lines are simple linear trend lines fit to the survey data.

Over time, nitrogen application rates (panel A) per acre have increased for corn and wheat. In 2024 estimated trend values are 151.8 pounds per acre for corn, a 10.8% increase from the average surveyed rate in 2002. The 2024 trend estimate for wheat is 77.15 pounds per acre, a 16.7% increase from the average surveyed application rate in 2002. Nitrogen applied per acre of soybeans has trended down, estimated at 18.5% lower in 2024 than in 2002.

Panel B shows that application rates per acre for phosphate have increased for corn (+11.2%) and soybeans (+10%) and declined for wheat (-8.9%). Panel C shows that application rates per acre for potassium have declined for all three major row crops: -6.6% for corn, -5.8% for soybeans, and -16.9% for wheat.

Trends in Applications per Bushel (Efficiency of Use)

Changes in application rates per acre have coincided with increasing crop yields over time. Yield or productivity increases have been larger than any of the increases in fertilizer application rates (Farmdoc Daily April 29, 2025 and June 6, 2023). As a result, application rates of N, P, and K per bushel produced have been declining for corn, soybeans, and wheat.

Efficiency of use is defined as pounds of fertilizer applied per unit of crop output (fertilizer applied per acre divided by crop yield). As shown in Figure 3, application rates per bushel for all crops are trending down, meaning less fertilizer is being used to produce each bushel.

Table 1 shows the comparison between observed USDA survey results from 2002 and trend estimates for 2024. The annual change in the last column of the table represents the compounded annual percent change in efficiency. A negative number means use has become more efficient. For example, corn used 1.06 pounds of nitrogen fertilizer to produce one bushel in 2002, and 0.85 pounds in 2024. This implies a 1.01% reduction in the use of nitrogen fertilizer per bushel of corn produced each year since 2002.

Discussion

The observed gains in fertilizer use efficiency are significant. For nitrogen, for instance, the efficiency of use for corn has increased 20% from 2002–2024. Considering the estimated production of 15.8 billion bushels of corn for 2025/2026 (WASDE 2025), the improvement represents approximately 1,500 thousand fewer metric tons of N fertilizer than would have been used to produce the same crop in 2002.

These improvements are the result of a combination of several factors, including genetic advancements, improved management practices, better timing of applications, better products, better access to information etc. In addition, yields and applications rates will vary a great deal depending on location, soil, target output and varieties (Farmdoc Daily, Oct. 25, 2023). However, this shows that fertilizer use is trending in the right direction.

Economically, from 2000–2024 fertilizer costs represented approximately 45% and 30% of total direct costs for corn and soybeans, respectively (Farmdoc Daily, April 30, 2024). Improved efficiency lowers the cost of production per bushel, which is especially important in years such as 2022 when fertilizer prices spike (Farmdoc Daily, Sept. 27, 2022, and June 18, 2024).

From the demand perspective, understanding trends in application rates is important since it impacts demand for fertilizer and, thus, prices and the management decisions made by farmers.

Improved fertilizer efficiency is also environmentally beneficial, contributing to sustainability goals by reducing nutrient runoff and lowering emissions per unit of output.

Conclusion

Fertilizer application rates per acre have increased for some nutrients and crops over time, while others have declined. Yields for the major row crops that account for the majority of N, P, and K fertilizer use in the U.S. have all increased over time. For the cases where application rates per acre have increased (N for corn and wheat; P for corn and soybeans), the yield increases have been relatively larger.

As a result, U.S. agriculture is applying less fertilizer per unit of output for major crops like corn, wheat, and soybeans. From an aggregate use perspective, there is little evidence of sharp changes in total fertilizer use due to trends in application rates and efficiency. Future trends in aggregate use will continue to be impacted to a greater extent by planted acreage and crop rotation decisions of farmers.

Note

[1] The NASS Agricultural Chemical Use Program does not survey crops consistently across years. Program states may also vary. This is an approximation based on the sum of reported total applications from 2002–2023 for the program states.

Trends in Fertilizer Use and Efficiency in the U.S. was originally published by Farmdoc.