Farm Talk


December 10, 2013

Keeping nitrates on the field

Parsons, Kansas — Keeping nitrogen fertilizer on farm fields, to support optimum crop growth, and out of streams and rivers is no simple formula. It’s complex.

 “Think ‘writing a novel’ versus ‘writing a recipe,’ ” said Matthew Helmers, an associate professor of agricultural and biosystems engineering at Iowa State University, where he is working with teams of scientists who are field-testing promising strategies, using a systems approach.

 Whether present naturally in the soil or added during chemical fertilizer application, nitrogen not taken up by crops can move with water flowing through soil during rains and snow melt, and into streams and rivers where excess nitrogen can cause adverse health and ecological effects. To address the issue of nitrogen and other farm nutrients leaving farm fields, ISU scientists, including Helmers, worked with scientists from the USDA-ARS, USDA-NRCS, the Iowa Department of Agriculture and Land Stewardship, and the Iowa Department of Natural Resources on the Iowa Nutrient Reduction Strategy Science Assessment, which was finalized in May.

 The Science Assessment highlighted that the state’s nonpoint source nitrate reduction goal of 41 percent becomes attainable only when the problem and the solutions are seen through a wide lens of interconnected ecological and social systems, which present a multitude of opportunities to minimize loss, said Helmers.

 “When we look at in-field and edge of field opportunities, for example, we can start by doing the best job we can, putting the right amount of nitrogen on as close as possible to when the crop needs it,” said Helmers.

 Helmers is a principal investigator on the field research team of the Climate and Corn-based Cropping Systems Coordinated Agricultural Project, also known as the Sustainable Corn Project. It’s a 10-university research project in the Midwest, funded by the USDA and led by Iowa State. Team members are gathering and analyzing field trial data from 35 field sites and thousands of farmers in eight Midwestern states in an effort to create a suite of practices that make corn-based cropping systems more resilient in response to climate change. The project includes field trials of practices, such as cover crops, which have the potential to reduce soil and nutrient losses under saturated soil conditions.

 Some of his colleagues on the Sustainable Corn team are testing fertilizer application done with equipment that senses the nitrogen needs of each plant and adjusts the rate of application accordingly.

 Applying nitrogen fertilizer in the “right amount and at the right time” is an essential step, but not enough, said Helmers, who sees opportunities for reduction “with every input and output of the cropping system.” Results from field trials have made him a staunch supporter of cover crops, which can hold nitrogen in the soil.

 “The Science Assessment showed that cover crops can reduce nitrate transport by approximately 31 percent. They are going to have to be a major player, if we want to reduce nutrient loading to water bodies downstream of row crops,” said Helmers.

 Other opportunities to reduce nitrate transport can be seen when studying what happens when water flows through and out of a cropping system.

 “In some areas we may be able to manage or treat the outflow from the subsurface drained landscape with practices like drainage water management, subsurface drainage bioreactors, wetlands or the emerging practice of saturated buffers,” said Helmers.

 To be successful and reduce unintended consequences, Helmers says related social and economic systems also need to be included. The Sustainable Corn research teams include social scientists, rural economists, extension specialists, farmers and farm advisors in addition to crop, soil and climate scientists.

 “We need to understand the agronomic side, the impacts of climate change, pests and pathogens and all of the economics of the practices we’re testing,” Helmers said. “The cropping system has to be profitable and we have to help farmers understand how to manage it and work with them to implement and figure out what works on their farm. Only this broad systems approach is going to be effective in helping us solve our water quality problems.” £

Text Only
  • cornplantlatemay2.jpg WASDE report eases low crop price fears

    USDA’s April 9 World Agricultural Supply and Demand Estimates continued a series of recent reports that have offered corn and soybean producers a more optimistic grain-price outlook than what was expected for most of the winter, Purdue Extension agricultural economist Chris Hurt says.

    April 15, 2014 1 Photo

  • USDA: Corn acres expected to drop 4%

    The amount of American cropland devoted to corn is expected to shrink about 4 percent this year as farmers devote more acres to soybeans, the U.S. Department of Agriculture said last week.

    April 8, 2014

  • Bt-resistant rootworms ID’d in five states

    Researchers say bugs are developing resistance to the widely popular genetically engineered corn plants that make their own insecticide, so farmers may have to make changes.

    April 1, 2014

  • MU economist: Corn, bean price volatility next 5 years

    Expect volatility in the soybean and corn markets over the next five years, said Pat Westhoff, director of the University of Missouri Food and Agricultural Policy Research Institute (MU FAPRI).
    Look for corn prices to drop to $4 per bushel and soybean to $10 per bushel on average for the next five years, he said.

    March 25, 2014

  • marestail.jpg Plan now to control marestail in soybeans

    Controlling marestail in soybeans has been a big challenge for Kansas no-till producers in recent years.
    Because soybeans are generally planted later in the season, and marestail generally germinates in the fall or early spring, application timing and weed size are critical factors to successful control.

    March 18, 2014 1 Photo

  • Checking alfalfa for winter injury

    In the last couple of weeks, I’ve heard many concerns about alfalfa production for this spring.
    Cold temperatures and lack of snow cover are the two main issues producers are worried about for next season’s crop production, as certainly the alfalfa plant could die if exposed to extremely cold temperatures. In general, alfalfa plants can tolerate up to three weeks of winter injury before the plants are killed.

    March 11, 2014

  • soypods.jpg USDA reports on status of GE crops

    Genetically engineered (GE) varieties with pest management traits became commercially available for major crops in 1996.
    More than 15 years later, adoption of these varieties by U.S. farmers is widespread and U.S. consumers eat many products derived from GE crops — including corn-meal, oils, and sugars — largely unaware that these products were derived from GE crops.

    March 4, 2014 1 Photo

  • wheat-head.jpg Everest still leads Kan. wheat acres

    For the second year in a row, a variety of wheat developed by Kansas State University, is the leading variety in Kansas.

    February 25, 2014 1 Photo

  • RickReimer.jpg Innovation, exports fuel soybean demand

    Brent Hayek is revved up about potential new uses for soybeans, and he is piling up the miles to share his enthusiasm.

    February 18, 2014 2 Photos

  • red_clover.jpg Seed legumes on snowy fields

    Winter seeding clover over grass pastures works best in February. Frozen fields are ideal and a snow cover makes seeding easier.

    February 11, 2014 1 Photo

Hyperlocal Search
Premier Guide
Find a business

Walking Fingers
Maps, Menus, Store hours, Coupons, and more...
Premier Guide
Seasonal Content