Over the years, the nitrate content in the world's multi-source water has increased year by year due to the application of large amounts of nitrogen fertilizer. Since the mid-1920s, the amount of nitrogen deposited on land has more than doubled, resulting in the increase of nitrate content in the source water. Researchers at Purdue University have developed a new type of urea that can be used to solve such problems.

"I believe we can use our technology to help cropping reduce environmental pollution," said Kingsly Ambrose, associate professor of agriculture and bioengineering and head of the research team. "We have developed a surface agglomeration controlled release granular urea, which consists of two layers and dissolves slower than existing urea granules on the market."

Ambrose said that one of the major challenges of urea use is its relatively low nutrient use efficiency and its inability to withstand the erosion of large amounts of running water or rainwater. Water will wash away most of the urea, causing economic losses and serious pollution.

"The urea granules we developed released slowly at the initial stage," explains Ambrose. "When the outer layer is completely saturated, the second layer of nutrients will be released. This slow dissolution method can reduce the nutrient loss caused by water erosion. Another advantage of this fertilizer is that its structural composition can improve the efficiency of nitrogen use and help to reduce the cost of fertilizer use.

The new fertilizer developed by Purdue researchers can be produced by the current granulation system in the fertilizer industry with simple installation.