Much of the nitrogen fertilizer used in the developing world never makes it into a plant. A lot of it evaporates or leaches away from the root zone, and so increases the cost while decreasing production. The losses to air and water are environmental problems since some are GHGs and some cause eutrophication of water.

Better nitrogen compounds and smarter application methods can make a big difference.

UDP [urea deep placement] is the insertion of large urea briquettes into the rice root zone after transplanting. UDP cuts nitrogen losses significantly. Farmers who use UDP can increase yields by 25% while using less than 50% as much urea as before. . .

broadcasting is a highly inefficient application method because most of the nitrogen is lost to the air and water. Only one bag of urea in three is used by the plants. . .

UDP technology was introduced in Bangladesh in the late 1990s; by 2006 more than half a million farmers had adopted UDP. Average paddy yields had increased 20% to 25%, and income from paddy sales increased by 10%, while urea expenditures decreased 32%.

The switch from ammonium bicarbonate to urea in China in recent years has had a similar effect. Ammonium bicarbonate literally evaporates. Stored loose in open containers or piles the loss can be 5% per day. Once broadcast on fields the rate increases. Very little actually benefits plants. That means that a great deal is used and that a great deal of unintended environmental impact occurs.

Both China and India need to get very good at agriculture. They need to be highly productive and keep costs low in order to feed their large populations and reduce environmental impacts. A great deal can be done by using better materials and methods.