b"Plant Breeding for Climate ChangeNitrogen Management About half of the fertilizer used in the United States goes to grow corn crops. A team of 27 labs across the country are working to find ways to create a more nitrogen-efficient corn production system that would be good for farmers and for the environment. Kristi CoxNITROGEN APPLICATIONplays a vital role in modern agriculture, bring-ing positive impacts on production from enhanced crop growth to increased crop productivity, to improved crop quality and balanced crop nutrition. However, it also carries negative impacts. In addition to its financial cost to farmers, nitrogen can cause significant environmental impact through run-off and greenhouse gas emissions.Edward Buckler, a research geneticist with the U.S. Department of Agricultures Agricultural Research Service (USDA ARS) and an adjunct professor at the Cornell University School of Integrative Plant Science, is studying how agriculture can mitigate nitrogen uses environmen-tal impact. He is leading a collaborative effort across the United States to create a more nitrogen-efficient corn produc-tion system. The teams strategies include adjusting planting schedules, optimizing nitrogen use and incorporating geneticSoil and root samples are collected from the field post-harvest in Chile. These samples traits from wild relatives of corn. Thesedetermine the depth achieved by roots of different soybean varieties, a trait critical for innovations aim to not only enhance sus- lengthening the amount of time carbon can be sequestered in the soil. Field trials started in tainability but also potentially boost crop2020 and span six states and two countries.PHOTO: BRYAN MILESyields: a win-win for all.Traditionally, nitrogen enters the crop- emissions, Buckler explains. The sameIn fact, whether a legume fixes nitro-ping system through the application of atype of thing is happening with the runoffgen from the atmosphere or has access significant amount of fertilizer, resultingof nitrogen into our waterways. We moveto nitrogen industrially produced as ferti-in large amounts of nitrate production.some to the atmosphere, and we loselizer, about 87% of nitrogen is lost before While a portion of nitrates are used tosome in our water. reaching the consumer, says Buckler.grow the crop, nitrate is highly mobile soWhile management practices canHes committed to finding a better can move within the soil profile and leachaccount for some of the losses, the chal- way. into waterways. It can also undergo reac- lenge is bigger than how farmers farm.Currently, about half of the fertilizer tions that lead to the emission of nitrousWe're just not very efficient at movingused in the United States is applied to oxide, a greenhouse gas. that nitrogen into protein that we can eat,corn crops. Buckler is leading a team of Agriculture as a whole, through theand that results in water pollution issues27 labs across the country to find ways flow of nitrogen into protein, is responsi- and greenhouse gas emissions that areto create a more nitrogen-efficient corn ble for about 11% of U.S. greenhouse gassubstantial, Buckler says. production system. 64/ SEEDWORLD.COMINTERNATIONAL EDITION 2024"