Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A Little Nitrogen Can Go a Long Way

05.09.2008
With recent increases in grain and fertilizer prices, even small changes in management may significantly impact profit as reported in Agronomy Journal.

Varying the rate of crop production inputs such as fertilizer and seed makes intuitive sense, as farmers have long observed differences in crop yield in various areas of a single field. The availability of spatial yield information from combines equipped with yield monitors has provided a good resource for improved management.

So, optimizing inputs to match yield potential of different areas within fields may increase profit and reduce the environmental impact associated with over-application of fertilizer or pesticides. With recent substantial increases in grain and fertilizer prices, even small changes in management may have the potential to significantly impact profit from a field.

Scientists with the University of Nebraska-Lincoln (UNL) compared an approach to site-specific nitrogen and seed density management for irrigated maize, based on soil properties and yield potential zones, to whole field uniform management based on current University of Nebraska best management practices (BMPs).

The researchers wanted to know if the site-specific approach could increase yield or nitrogen-use efficiency (the amount of grain produced per kilogram of nitrogen applied), and the effect of site-specific management on profitability. The study was conducted on two irrigated maize fields in Nebraska in 2003 and 2004 -- a total of four site-years.

Four treatments were then compared each year in field length strips, evaluating uniform management of nitrogen and seed density (current BMP), variable nitrogen rate plus uniform seed density, uniform nitrogen rate plus variable seed density, or both variable nitrogen rate and seed density. The variable nitrogen rate was based on yield potential within each zone, spatial patterns of soil organic matter within each zone, and zone-average residual soil nitrate-nitrogen values, using the University of Nebraska recommendation algorithm for maize.

Yield levels in both years generally followed the order of historical yield zones, though at Site 1 in 2003 average grain yields were not different among yield zones. Uniform nitrogen and seed density management resulted in high yields for all four site years, and site-specific management strategies resulted in no or small yield increases. Only at Site 1 in 2003 were there small but statistically significant yield increases with variable rate nitrogen management. There were no significant effects of seed density on yield, nor any interactions between seed density and nitrogen rate.

Fertilizer nitrogen use efficiency (NUE) was high in all site-years and well above national averages. NUE was particularly influenced by the amount of residual nitrate-nitrogen present in the soil profile prior to planting. At Site 1, NUE tended to be highest with the strategy that combined variable rate nitrogen with uniform seed density. At Site 2 in 2003, there was no advantage to variable rate nitrogen in NUE, while in 2004 a variable rate strategy which applied more nitrogen in high-yielding areas of the field resulted in the highest NUE.

At Site 1 in 2003, variable rate nitrogen management increased the gross economic return above fertilizer costs. However, for the other three site-years, there were no significant effects of site-specific management on profitability.

The conclusion of the study was that, using the strategies the researchers selected, they could not demonstrate consistent significant economic benefits to site-specific management. One site-year did indicate an economic benefit to site-specific management, but this was before costs associated with collecting and analyzing site-specific information were included. However, this economic analysis was conducted using 2004 values of grain and fertilizer.

With significant increases in the price of fertilizer and the value of grain in 2007 and 2008, the value of using site-specific management is likely to have increased for those locations where site-specific management has a significant impact on yield, NUE, or both.

The researchers believe variable rate nitrogen application will be most profitable in situations with relatively wide maize to nitrogen fertilizer price ratios, and where a significant yield increase over uniform management is likely. They found little benefit to variable seed density, likely due to plasticity in yield components in response to different plant populations. Site-specific adjustment of seed density in irrigated environments is probably best applied to areas of known low yield potential in order to reduce seed cost.

A peer-reviewed international journal of agriculture and natural resource sciences, Agronomy Journal is published six times a year by the American Society of Agronomy, with articles relating to original research in soil science, crop science, agroclimatology and agronomic modeling, production agriculture, and software. For more information visit: http://agron.scijournals.org.

The American Society of Agronomy (ASA) www.agronomy.org, is a scientific society helping its 8,000+ members advance the disciplines and practices of agronomy by supporting professional growth and science policy initiatives, and by providing quality, research-based publications and a variety of member services.

Sara Uttech | EurekAlert!
Further information:
http://www.agronomy.org
http://agron.scijournals.org

Further reports about: Agronomy crop crop production farmer fertilizer maize nitrate-nitrogen nitrogen pesticides

More articles from Agricultural and Forestry Science:

nachricht New gene for atrazine resistance identified in waterhemp
24.02.2017 | University of Illinois College of Agricultural, Consumer and Environmental Sciences

nachricht Researchers discover a new link to fight billion-dollar threat to soybean production
14.02.2017 | University of Missouri-Columbia

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>