Global Warming Issues

From the rockets’ red glare to bombs bursting in air, researchers are developing more environmentally friendly fireworks and flares to light up the night sky while minimizing potential health risks, according to an article scheduled for the June 30 issue of Chemical & Engineering News. Some eco-friendly fireworks may soon appear at a Fourth of July display or rock concert near you.

In the C&EN cover story, Associate Editor Bethany Halford points out that fireworks, flares and other so-called pyrotechnics commonly include potassium perchlorate to speed up the fuel-burning process. But some studies have linked perchlorate, which can accumulate in the soil, air and water, to thyroid damage. Pyrotechnics also contain color-producing heavy metals, such as barium and copper, which have also been linked to toxic effects.

Researchers recently developed new pyrotechnic formulas that replace perchlorate with nitrogen-rich materials or nitrocellulose that burn cleaner and produce less smoke. At the same time, these nitrogen-rich formulas also use fewer color-producing chemicals, dramatically cutting down on the amount of heavy metals used and lowering their potentially toxic effects. Some of these fireworks are already being used at circuses, rock concerts, and other events.

The big challenge in developing these “eco-friendly” pyrotechnics is making them as cost-effective as conventional fireworks while maintaining their dazzle and glow, the article states.

Crop yield is highly dependent on soil plant-available water, the portion of soil water that can be taken up by plant roots. Quantitative determination of the maximum amount of plant-available water in soil using traditional methods on soil samples remains challenging, especially at the scale of an entire field.

However, a map of plant-available water capacity for a field would be instrumental in yield potential assessment and site-specific soil and water management, making the search for improved methods of soil plant-available water quantification an important step towards improved crop productivity and management.

One of the alternative methods designed to rapidly and economically estimate plant-available water capacity for a field is the Simple Inverse Yield Model (SIYM). The SIYM first simulates crop yield using a water-budgeting algorithm and growing season weather conditions such as radiation, temperature, and rainfall. As such, yield values can be simulated for a range of levels of soil plant-available water. In the following model step, plant-available water values can subsequently be obtained by matching measured crop yield with the closest simulated yield on a yield map.

A group of researchers at the University of Missouri and the USDA-ARS (Cropping Systems and Water Quality Research Unit) investigated the applicability and performance of the SIYM for poorly-drained claypan soils in Central Missouri, and compared them to well-drained soils where the model was first developed and tested. For the study, a total of nine corn yield maps were generated using data collected from two fields in Central Missouri during 1993 to 2005. Soil samples were taken to determine plant-available water capacity using traditional laboratory methods.

Results showed that measured plant-available water capacity correlated with corn yield better in dry years than in normal or wet years. Agreement between measured plant-available water and SIYM estimates was weaker in the claypan soils than well-drained soils, especially at locations where the claypan layer was shallow or exposed at the surface. At these locations, plants cannot utilize all the plant-available water in the soil, due to slow water transport in clay-rich soils. As a result, yields simulated by SIYM tended to be higher than measured yields, and thus SIYM-estimated plant available water capacity tended to be lower than measured plant-available water capacity.

The lead author, Pingping Jiang, stated “Compared to the measured plant-available water using traditional methods, the SIYM estimates may be more useful in assessing soil productivity and making site-specific management decisions. SIYM is based on actual yield measurements, and less strongly on conventional soil measurement techniques, which do not take crop-soil-water interactions into account.”

This research was a part of continuing research at the USDA-ARS Cropping Systems and Water Quality Research Unit to assess field variability for site-specific management.

By Jeff Huggins

There was an eruption of assertions in recent days that the increasing summer retreats and thinning of Arctic Ocean sea ice might be a result not of atmospheric warming but instead all the heat from the recent discovered volcanoes peppering the Gakkel Ridge, one of the seams in the deep seabed at the top of the world.

Several experts said it was not plausible from the get-go, but for the sake of due diligence, I queried a heap of the Arctic oceanographers and climate and ice experts I’ve gotten to know since my North Pole journey in 2003. They uniformly reject the idea that heat from the bottom — either from the general geothermal activity beneath the seabed or the occasional outbursts of lava or vents — could have a significant impact on the veneer of floating, drifting ice on the surface.

The deep saltier, warmer water is largely isolated from the cold, fresher waters near the surface, they say. I’ve listed some responses below, with more to come. I’m in transit and can’t transliterate some of the techno-speak at the moment, but wanted to get this post up while the issue is still burbling in the blogosphere.

DENVER — Under increasing public pressure over its decision to temporarily halt all new solar development on public land, the Bureau of Land Management said Wednesday that it was lifting the freeze, barely a month after it was put into effect.

The bureau had announced on May 29 that it was no longer processing new applications to build solar power plants on land it oversees in six Western states after federal officials said they needed first to study the environmental effects of solar energy, a process that would take two years.

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