Leakages of nutrients necessary for food production – especially nitrogen and phosphorus – cause severe eutrophication to the Earth's aquatic ecosystems and promote climate change. However, this threat also hides an opportunity.
When exposed to nitrogen fertilizer over a period of years, nitrogen-fixing bacteria called rhizobia evolve to become less beneficial to legumes - the plants they normally serve, researchers report in a new study.
By Molly Hamilton, Extension Assistant, Crop Science, North Carolina State University
Properly timed spring nitrogen applications are essential to the growth and development of wheat. Assessing nitrogen needs now will optimize yield later and is especially important for organic grain growers.
By Jim Camberato and R.L. (Bob) Nielsen, Purdue University
Applying “more than enough N” is no longer cheap “insurance” as it once was many years ago. Applying “more than enough N” is also not environmentally friendly. High N fertilizer costs and environmental impacts should encourage growers to critically evaluate their N management program, including application rate, fertilizer material, and timing.
By Tim Harrigan, Michigan State University Extension
Nitrogen and phosphorus are nutrients that are essential for crop growth and profitability, but crop nutrients that escape from the field are potential pollutants. Cropland tends to be nutrient-rich and runoff from the farmstead, pastures and fields can transport sediment, organic solids, nutrients and other contaminants to surface waters.
Upriver in Iowa, Agricultural Research Service scientists Rob Malone, Tom Kaspar, and Dan Jaynes are using the Root Zone Water Quality Model (RZWQM) to assess how using winter rye cover crops in corn-soybean rotations could mitigate nitrate loads in field drainage water.
New technologies are being developed to keep nitrogen in place and available to crops. But will farmers adopt these technologies? A new study by McCann in the Journal of Environmental Quality aimed to answer that question.