The Legacy Of Nitrogen

Image credit: Blue-green algae bloom Kisumu bay, Lake Victoria Kenya

"The greatest catastrophe that the human race could face this century is not global warming but a global conversion to ‘organic farming'-an estimated 2 billion people would perish.” - words of respected Cambridge chemist John Emsley

In late 2004, Kisumu bay, Lake Victoria, was covered in a blue-green hue.  Pretty to look at but with deadly connotations. The algal bloom  - a proliferation of cyanobacteria – demarcated an area of low oxygen and eventually decomposing algae, causing fish to suffocate or flee - a dead zone. It contaminated the primary drinking water source for a population of nearly 500,000 at the time. It has been documented in various studies around the world, that since 2004, algal blooms like these have shut down the water supply of more than 3 million people on three different continents. A result, in large part, of agricultural waste in the form of nitrogen-based fertilizers finding its way into lakes, rivers, and oceans around the globe. Adapt-N, a software programme developed by researchers at Cornell University seeks to solve this problem.

The problem with Nitrogen

Nitrogen is a nutrient essential to the growth of the plants we eat. In its inert form, it is harmless, making up 78% of the earth’s atmosphere. But as a result, in large part, to the mass production of nitrogen-based fertilizers massive amounts of reactive nitrogen compounds have been introduced into the environment, posing a danger to the ecosystem.

Because of the inefficient uptake of nitrogen by plants and animals, only 10 – 15% of nitrogen makes it to our tables as food. Microorganisms in the soil take advantage of the excess to thrive, releasing nitrous oxide – a greenhouse gas 300 times more potent than carbon dioxide - into the atmosphere. The rest is lost through surface run off and leaches through waterways creating dead zones and contaminating drinking water.

Reactive nitrogen cycles endlessly through the environment; something that University of Virginia environmental sciences professor James Galloway refers to as the ‘nitrogen cascade’. 

The Nitrogen Cascade

A nitrogen atom that starts out as part of a smog-forming compound may be deposited in lakes and forests as nitric acid, which can kill fish and insects. Carried out to the coast, the same nitrogen atom may contribute to red tides and dead zones. Finally, the nitrogen will be put back into the atmosphere as part of the greenhouse gas nitrous oxide, which destroys the atmospheric ozone.

"A unique and troublesome aspect of nitrogen is that a single atom released to the environment can cause a cascading sequence of events, resulting ultimately in harm to the natural balance of our ecosystems and to our very health," says Dr. Galloway.

Precision Nitrogen Application

Adapt-N is a web-based nitrogen recommendation tool for corn crops that was developed over 10 years. An effort led by Professor Harold van-Es. 

“Any time you put nitrogen in a reactive form in the soil, you can lose a lot of it within a matter of a couple days,” Dr. van Es told the Guardian

“With greenhouse gases, most people think about carbon dioxide and maybe methane, but people don’t think about nitrous oxide and it’s a very big concern,” says Dr van Es. “If you were to say within the aviation industry we can reduce our carbon footprint by 25%, people would be saying well that’s fantastic, that is big news. We think we can do that with nitrous oxide.”

Using high-resolution climate data, the tool provides agronomists and farmers valuable real-time information about the nitrogen needs in their fields. Allowing farmers to adapt the application of fertilizers based on need. Hence the name Adapt-N. This precision in the use of nitrogen-based fertilizers thus mitigates their environmental impact.

How it works

Farmers input field-specific information including soil composition, field history, as well as the amount of fertilizer they apply to their fields and when. The program combines this information with real-time weather monitoring to track the nitrogen’s likely fate. It sends farmers and agronomists daily email updates and allows them to retroactively explore field histories.

As a web-enabled technology it can be used by anyone with a computer, smartphone or tablet and access to the Internet. No specialized field equipment is required – making it potentially accessible to many farmers across the world.

At present, Adapt-N is in use in the U.S. monitoring cornfields, however, versions of the software to cover other crops such as wheat are currently under development.

In Kenya, maize growing is very popular among farmers as it is a crop in high demand. Both for local consumption (it is a staple in many households in the form of ugali and a popular dish mixed with beans) and for export. In the Western part, one of the main maize growing regions in the country, however, the long-term use of nitrogen-based fertilizers has led to high acidity in the soils resulting in reduced yields.

The fear of scarcity

Nobel Prize-winning plant breeder Norman Borlaug at a 2002 agricultural policy conference said, “We aren't going to feed 6 billion people with organic fertilizer” and added “If we tried to do it, we would level most of our forest and many of those lands would be productive only for a short period of time.”    

Sentiments such as these have been the impetus behind fertilizer-laden conventional farming practices. So much so that a major preoccupation of the Kenyan government has been to provide subsidized fertilizers to smallholder farmers across the country. To ensure crop yields. 

In Uasin Gishu – in the Rift Valley, an area considered Kenya’s breadbasket, the government has partnered with Toyota to set up a chemical fertilizer plant to ensure a constant supply to farmers around the country. Plans to set up a similar plant in Nakuru are said to be underway.

But all this focus on fertilizer may be misinformed. Studies such as those by the Research Institute for Organic Agriculture in Switzerland have shown that organic farming is not only capable of feeding the worlds’ billions, but when well managed, its yields can surpass even those of conventional agriculture.

It will however take a lot more than a few studies to cause the total abandonment of synthetic fertilizer in favor of organic alternatives. That will require years of education and a shift in the mind-sets of conventional agriculture proponents as well as a change in the strategies of Big Ag corporations, which rake in tidy profits from the manufacture and sale of these fertilizers. Until such a utopia is reached, solutions like Adapt-N may just be what we need to change the legacy of Nitrogen.