New Natural Nitrogen Sources

Farmers pay a lot of money for nitrogen (N) fertilizer, especially on corn and wheat but also vegetable crops like tomatoes, pickles, melons, sweet corn, etc. Most N fertilizer is produced from 200 plants world wide using the Haber-Bosch process. Natural gas or coal is used with atmospheric N using high pressure and high temperatures. The coal or natural gas is a source of hydrogen while the atmosphere supplies the N to produce ammonia (NH3). About 96% of the N fertilizer is produced this way but it also has high greenhouse gas emissions, methane and carbon dioxide. The need for N fertilizer is currently about 100 billion tons per year.

The atmosphere is a natural source of N at 78%. Worldwide, there may be 4,000 trillion tons of total N atmospheric worldwide or about 34,000 tons of N/acre. Almost all of this N is in in the wrong form for plants. However, lightning can fertilize our crops adding 1 to 50 pounds (lb) of natural N per acre. Lightning converts nitrogen molecules with high temperature by nitrogen fixation into nitrites and nitrates which are called nitrogen oxides. When it rains, the nitrates are a common source of N fertilizer. Every single day, almost 10,000 tons of N fertilizer are produced by lightning.

In 2018, researchers from Stanford University began experimenting with plasma to mimic lightning to form N fertilizer. They formed a company called Nitricity, Inc. The advantage of producing N fertilizer this way is that it can be produced on farm using solar panels, atmospheric N, and water. The good news is that greenhouse gasses emissions are much less but it costs more than regular fertilizer. Most common nitrogen fertilizer costs are around 48 cents/lb for anhydrous ammonia, 67 cents/lb for urea, while liquid forms of N cost 72 cents up to a dollar per pound. For a small one-acre systems using Nitricity technology, the cost is $3-4/lb of N but as the size increases to 25 acres, the cost goes down to about $1.50 per acre. It really depends on how much N is needed per acre. The system can also produce calcium nitrates and potassium nitrate which are common fertilizers. Currently, most of this N is applied in irrigation systems as a low-rate continuous source of N which is good for efficient use of N fertilizer.
 
Several companies are looking to use this technology. Green Lightning is another company that uses the lightning process to make N fertilizer by creating lightning in the form of plasma in a controlled environment under the same premise. Air and water is combined in a static electric field for the nitrogen molecule to go through the rearrangement process. It attaches itself to the water, flows through the machine, and drips out the bottom of this machine as nitrite (NO2) and nitrate (NO3).

USA researchers are also incorporating genes from Mexican corn into USA corn varieties to make N naturally on brace roots. A certain variety of Mexican corn has a gene that allows plant acquire nitrogen from the air through a process called nitrogen fixation. It similar to the process that soybean nodules make N. Mexican corn brace roots secrete a gel-like substance called mucilage. The mucilage creates a low-oxygen, sugar-rich environment that attracts nitrogen- fixing bacteria. The bacteria convert the atmospheric N into a form the corn plant can use. In the future, corn may not need much N, may only starter N to get a good corn crop.

All these new discoveries and innovations may soon help lower the cost of N fertilizer for crop production. However, they may still be a few years away. With low corn prices (around $3.50 per bushel), farmers are reluctant to plant corn because of the high N fertilizer costs. For farmers that have wheat and have not planted double crop soybeans, now is an excellent time to plant legumes and clovers as a cover crop into the wheat stubble to generate natural N fertilizer.

Cowpeas, hairy or common vetch, and Austrian Winter Peas are excellent legumes that may produce up to 150 pounds of N per acre or more if you get a solid stand. For clovers, Balansa, crimson and red clover can also produce large amounts of natural N fertilizer. All these crops grow better if planted early (August-September) to get a good stand. All legume and clover cover crops should be inoculated with the proper rhizobium bacteria to maximize N nodule production. Building soil organic matter is still a great source of natural N and it keeps the soil and nutrients in place.