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A Little Nitrogen Can Go a Long Way
September 04, 2008Varying 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.
The American Society of Agronomy (ASA)
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.
The American Society of Agronomy (ASA)
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Study of agricultural watersheds and carbon losses
Dissolved organic carbon (DOC) losses from tile drains are an underquantified portion of the terrestrial carbon cycle.
U-M researcher and colleagues predict large 2009 Gulf of Mexico 'dead zone'; Chesapeake Bay's oxygen-starved zone likely to shrink
University of Michigan aquatic ecologist Donald Scavia and his colleagues say this year's Gulf of Mexico "dead zone" could be one of the largest on record, continuing a decades-long trend that threatens the health of a half-billion-dollar fishery.
NOAA Forecast Predicts Large
A team of NOAA-supported scientists from the Louisiana Universities Marine Consortium, Louisiana State University, and the University of Michigan is forecasting that the "dead zone" off the coast of Louisiana and Texas in the Gulf of Mexico this summer could be one of the largest on record.
Scientists sequence genome of the N2-fixing, soil-living bacterium Azotobacter vinelandii
A collaboration of researchers, which includes scientists at the Virginia Bioinformatics Institute (VBI) and Virginia Tech, have completed the genome sequence of Azotobacter vinelandii, uncovering important genetic information that will contribute to a more complete understanding of the biology of this versatile, soil-living bacterium.
Extreme makeover chemistry style
In revisiting a chemical reaction that's been in the literature for several decades and adding a new wrinkle of their own, researchers with Berkeley Lab and the University of California (UC) Berkeley have discovered a mild and relatively inexpensive procedure for removing oxygen from biomass.
Caltech scientists predict greater longevity for planets with life
Roughly a billion years from now, the ever-increasing radiation from the sun will have heated Earth into inhabitability; the carbon dioxide in the atmosphere that serves as food for plant life will disappear, pulled out by the weathering of rocks; the oceans will evaporate; and all living things will disappear.
Ethanol Production Could Jeopardize Soil Productivity
There is growing interest in using crop residues as the feedstock of choice for the production of cellulosic-based ethanol because of the more favorable energy output relative to grain-based ethanol.
Studies shed light on collapse of coral reefs
An explosion of knowledge has been made in the last few years about the basic biology of corals, researchers say in a new report, helping to explain why coral reefs around the world are collapsing and what it will take for them to survive a gauntlet of climate change and ocean acidification.
New rotors could help develop nanoscale generators
In collaboration with the Chinese Academy of Sciences in Beijing, scientists have investigated the rotation of molecules on a fixed surface to understand how they may help in the development of future rotor-based machinery at nanoscale level.
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The World's Greatest Fix: A History of Nitrogen and Agriculture by G. J. Leigh (Author) In the tradition of Jared Diamond's Guns, Germs, and Steel, this gives the very early history of how human ingenuity overcame the risk of famine through productive agriculture. Starting with a layman's guide to the chemistry of nitrogen fixation, the book goes on to show how humans emerged from nomadic lifestyles and began developing towns and settlements. When they for the first time began planting the same fields year after year, they noticed quickly the need to ensure soil fertility. But how? The method they came up with is still in use to this day. |
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Nitrogen Air Tank 10lb Aluminum by KegWorks This tank is perfect for Guinness! This is a mixed gas tank featuring a siphon tube that extends 3/4 down the tank. This siphon tube ensures that gas is maintains the correct mixture needed for a perfect pint of Guinness. This Nitrogen cylinder is produced from high strength aluminum alloy. Enjoy the benefits of aluminum tanks - lighter than steel tanks, and do not rust! A nitrogen gas regulator is required. In stock and ready to ship. Features: Made of high quality aluminum. For serving Guinness. . . . . Specs: Dimensions: 20"H x 7"D. Weight: 14.25 ib. 20-Cubic foot capacity. Dispense 3 - 4 half kegs. 1800 service rating. |
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Pure Energy Fixed - 5 Year N2 Tank - 48ci 3000psi by Pure Energy Get ready to play year round with no troubles, it's time to put the C02 away and go with nitrogen. Features: Consistent Flow Technology piston Mil-spec Belleville springs Dual safety rupture plugs for both bottle and downstream safety Mechanical gauge Nickel plated brass bonnet Certified fill nipple and dual locking set screws Preset at 850 psi Approximately 500 shots per fill 5 year hydro test date Note: This tank DOES have a TC Stamp |
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Nitrogen in the Environment, Second Edition by Academic Press Nitrogen is one of the most critical elements for all life forms. In agricultural systems it is essential for the production of crops for feed, food, and fiber. The ever-increasing world population requires increasing use of nitrogen in agriculture to supply human needs for dietary protein. Worldwide demand for nitrogen will increase as a direct response to increasing population. Nitrogen in the Environment provides a wholistic perspective and comprehensive treatment of nitrogen. The scope of this book is diverse covering a range of topics and issues related to furthering our understanding of nitrogen in the environment at farm and national levels. Issues of nitrogen from its effects on crops and human nutrition to nitrogen in ground water, watersheds, streams, rivers, and coastal... |
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30 Lbs. Barley - Certified Organic - 30 Lb Nitrogen Packed Re-sealable Bucket - Barley Grain Seeds for Sprouting, Planting, Ornamental Grass, Growing & Juicing Barley Grass for Barleygrass Juice, Beer Making, Food Storage, Hydroponics, Grinding for Bread Flour & More. Long Shelf Life Seed. by Living Whole Foods 30 Lb Nitro-Packed Bucket of Certified Organic Unhulled Barley Seed. |
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RACE TECH TOOL NITROGEN HOSE TSNH48 by RACE TECH High quality at low cost Nitrogen gauge pro is a 0-300 psi gauge that does not require a wrench and reaches hard-to-get valve stems Nitrogen hose is a special 800 psi hose with finger-tight 1/4`` flare nut quick couplings Photo`s are for reference only. Please read item title carefully. |
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