Iron deficiency in soil threatens soybean production

Dec 06, 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: Idaho aquifer decline could hinder radioactive monitoring

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

Related Stories

Nitrogen applied

Oct 01, 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.

How much nitrogen is too much for corn?

Apr 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 ...

Recommended for you

Pace of climate talks far too slow: UN chief

9 hours ago

UN Secretary-General Ban Ki-moon said Monday that negotiations on climate change were moving too slowly and urged governments to quicken the pace ahead of the December conference on reaching a new global ...

Justices rule against EPA power plant mercury limits

12 hours ago

The Supreme Court ruled Monday against the Obama administration's attempt to limit power plant emissions of mercury and other hazardous air pollutants, but it may only be a temporary setback for regulators.

Food for thought: Use more forages in livestock farming

12 hours ago

Small-scale livestock farming in the tropics can become more intensive yet sustainable if more and better forage is used to feed the animals being reared. This could benefit farming endeavours in rural South ...

User comments : 0

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.