Money, Energy and Nitrogen

By Stuart A. Lee
State Public Affairs Specialist
North Carolina - Natural Resources Conservation Service (NRCS)

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Nitrogen fertilizer requires massive amounts of energy to produce, and it is expensive to use. For the farmer, finding ways to reduce the amount of nitrogen needed, and by using it more efficiently in agricultural production, can save money and help our nation reduce its dependency on nonrenewable energy resources. Yet the important question is – why? Why is nitrogen fertilizer expensive for the farmer, and why does it consume so much energy?

Nitrogen is absolutely everywhere. In fact, this vital element makes-up 80 percent of our atmosphere. Though it is abundant it isn’t particularly cheap to produce in a “plant-friendly” form, which is hard on the farmer’s wallet. Lightning strikes, blue-green algae, bacteria in legumes, and rainfall that washes pollutants from the air can all return nitrogen to the soil for plant consumption.  Of these, only legume plants can deliver sufficient amounts of nitrogen, naturally, for high-yield cultivation. 

Manufacturing nitrogen requires extremely high temperatures and pressure.  Herein lies the problem.  To produce the high temperatures needed to create nitrogen, natural gas is used. One-ton of nitrogen fertilizer (anhydrous ammonia) demands the use of 33,500 cubic-feet of natural gas. Natural gas accounts for 90 percent of the cost of producing nitrogen fertilizer. Consequently, the more nitrogen fertilizer produced, the more gas needed; the higher the price of natural gas, the higher the cost nitrogen based fertilizers.

For the farmer, reducing the amount of nitrogen fertilizer can be cost efficient and help decrease natural gas consumption.   Choices of fertilizers with lesser amounts of nitrogen (N) are: urea (45-46% N); solutions (28- 32% N); ammonium sulfate (21% N); and ammonium nitrate (34% N).  More cost-efficient and energy saving alternatives to nitrogen fertilizers are, using animal manure, and planting nitrogen producing legumes as cover crops.   Additionally, when farmers consider the time, place, source and amount of nitrogen to meet the nutrient needs of the plant, they can also improve efficiency.

To help farmers identify potential ways of reducing energy used and to help them find ways to save money, the USDA’s Natural Resources Conservation Service (NRCS) created a Web-based tool called the Energy Estimator for Nitrogen. This NRCS energy consumption estimation tool enables the farmer to calculate the cost of nitrogen product used on their farm. NRCS agronomists have developed these cost estimates based on nitrogen fertilizer management methods for the predominant crops for each state. It also provides possible options based on the user’s input.  NRCS encourages users to discuss options suggested by the estimator with their local NRCS office and to learn about technical and financial assistance for implementing energy efficient conservation management practices.

The Energy Estimator for Nitrogen is available on the Web at www.nc.nrcs.usda.gov by selecting the “Save Energy Save Money” icon on the North Carolina NRCS homepage. The estimator should not be a sole source of decision-making on nitrogen fertilizer application, but rather a source of guidance. The estimator will provide the user with contact information for their local USDA Service Center, and provides Web-links to state and university soil and nitrogen information. NRCS recommends that farmers take their nitrogen fertilizer estimates to their local NRCS Field Office, Extension Office or the crop consultant.

By looking at alternatives to nitrogen fertilizers and improving application practices, cost and energy savings are achievable. The first step in saving money, energy and conserving natural resources is to be proactive in researching alternatives to typical fertilization practices, and by developing a well developed conservation plan.

 The USDA is an equal opportunity provider and employer.

Last Modified 10/27/2009

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