Iron deficiency in soil threatens soybean production

December 6, 2010

An expansion of soybean production into areas where soybean has seldom, if ever, been grown can be problematic for some farmers. Soils having high pH values and large amounts of calcium and/or magnesium carbonate are notoriously iron deficient. Iron deficient soils in the North Central United States are estimated to reduce soy bean production by 12.5 million bushels every year.

John Wiersma, a researcher at the University of Minnesota Northwest Research and Outreach Center at Crookston, concluded a study examining the effect of nitrogen based on soybean crops grown in iron deficient soil. Because soybeans require more nitrogen than most commercial crops, Wiersma hypothesized that adding nitrogen fertilizer could help increase yields in nutrient poor .

Several soybean varieties along with were tested from 2003-2005 on soils where soybean has historically exhibited mild to severe iron deficiency. Seed was inoculated at twice the recommended rate, and the amount of extractable iron in soils of the experimental areas was measured each year. Growing season temperature and rain also were recorded each year and compared with each other and with the 30-year average for Crookston.

According to Wiersma's study, plant height, seed number, and grain yield all decreased linearly in response to increasing nitrogen rates for iron inefficient varieties, whereas these responses in iron efficient and moderately efficient varieties changed little as nitrogen rates increased.

"Additional nitrogen definitely should not be applied when iron-inefficient varieties are grown on chlorosis-prone (iron deficient) soils, and there is little support for adding nitrogen to iron efficient or moderately efficient varieties," states Wiersma.

Research is ongoing at Crookston to compare the accuracy and consistency of different measures of in soybean crops. Wiersma's study can be found in the 2010 November/December issue of .

Explore further: How much nitrogen is too much for corn?

More information: View the abstract at www.agronomy.org/publications/aj/abstracts/102/6/1738

Related Stories

How much nitrogen is too much for corn?

April 23, 2007

North Carolina State researchers recently discovered a test that quickly predicts nitrogen levels in the humid soil conditions of the southeastern United States. These scientists report that the Illinois Soil Nitrogen Test ...

Nitrogen applied

October 1, 2008

Combating soil erosion is a primary concern for agricultural producers in the United States, and many have incorporated conservation tillage systems in their effort to maintain a profitable crop output.

Recommended for you

What would a tsunami in the Mediterranean look like?

August 27, 2015

A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal ...

Intensity of desert storms may affect ocean phytoplankton

August 27, 2015

Each spring, powerful dust storms in the deserts of Mongolia and northern China send thick clouds of particles into the atmosphere. Eastward winds sweep these particles as far as the Pacific, where dust ultimately settles ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.