Scientists develop 'interactive' crop system that signals water, fertilizer needs of individual plants
Along with continuous breakthroughs in biotechnology and nanotechnology, it is this type of inventions with major implications for global agriculture that may make the most optimistic long-term biofuel scenarios more realistic.
Interactive agriculture
According to research associate Hans-Dieter Seelig from CU-Boulder's BioServe Space Technology Center, which develops products based on space life science research, the interactive technology includes a tiny sensor that can be clipped to plant leaves charting their thickness, a key measure of water deficiency and accompanying stress, Data from the leaves could be sent wirelessly over the Internet to computers linked to irrigation equipment, ensuring timely watering, cutting down on excessive water and energy use and potentially saving farmers millions of dollars per year.
Based in large part on Seelig's 2005 CU-Boulder doctoral thesis in aerospace engineering sciences, the technology was further developed at BioServe, a NASA Research Partnership Center for the commercialization of space. It was originally designed for use in conserving water for plant growth during long-term space flight. The new system was optioned to AgriHouse Inc., a high tech company from Colorado, in March by the University of Colorado Technology Transfer Office, giving AgriHouse the exclusive right to negotiate a license with CU within 12 months. "We think this is an exciting technology, and the implications for the agriculture industry are enormous," said Seelig.
Existing technology like soil moisture sensors used to assess a crop's water needs do not always provide an accurate picture of existing plant and field conditions.
"What we are developing is a non-intrusive device that gently rests on the plants and lets them interface with the digital world. Basically, this is a device that will allow plants to talk to humans and communicate their needs, like when to water and apply fertilizer." - Richard Stoner, AgriHouse founder and president.Less than one-tenth the size of a postage stamp, the sensor consists of an integrated-circuit chip that clips to individual plant leaves and collects and stores information, said Seelig. When the leaves lose enough water to contract to a critical width, the sensor can wirelessly signal computers:
biomass :: bioenergy :: biofuels :: energy :: sustainability :: agriculture :: fertilizer :: water :: irrigation :: water-stress :: sensors ::
The computers, for example, could instruct individual pivot irrigation systems used widely on Colorado's eastern plains to dispense set amounts of water to particular crops, automatically turning the motors that drive them on-and-off and conserving water and energy in the process, he said.
"Farmers today rely on standard practices that include a good eye and a green thumb," said Stoner. "But this new system can tell a farmer precisely when a plant's water uptake potential is at its peak, which could conceivably decrease the number of watering days for certain crops by up to a day or two each week."
Economists estimate that agricultural activity accounts for about 40 percent of the total freshwater use in the United States. About 60 percent of all crops in the United States are irrigated using water from lakes, reservoirs, wells and rivers.
Stoner likened the plant communication aspect of the invention to a scene in the 1986 comedy musical film, "Little Shop of Horrors," when a giant carnivorous plant tells humans to "feed me." "This technology allows plants to say, 'water me,' " he said.
High eastern plains water-use has led to lawsuits against Colorado for violations of interstate water compacts, including a recent $30 million payment to Kansas for overuse of the Arkansas River, said Seelig. A recent U.S. Supreme Court lawsuit against Colorado and Nebraska for overuse of Republican River water threatened to shut down all Colorado wells impacting the river if solutions for reducing irrigation water are not found. Farmers irrigate nearly one-half million acres on the eastern plains from the Ogallala Aquifer that directly impacts the Republican River, he said.
The researchers have been experimenting with cowpea, a legume, but believe the new leaf-sensor technology would be transferable to a variety of crops, including corn, wheat, potatoes, sugar beets and pinto beans. In the future, it might also be applicable to monitoring large swaths of urban grass like city parks, Stoner said.
"This device is very precise, and will allow a plant to receive just the right amount of water," said Seelig. "If a plant can tell a water valve when to open and when to close, farmers are going to save a lot of money."
Background
In 1997, Stoner and AgriHouse teamed up with BioServe and NASA on plant-growth experiments and hardware shipped to Russia's Mir Station, experiments which led to the development by AgriHouse of a commercial, all natural crop-boosting product known as "Beyond." AgriHouse has received two NASA Small Business Innovation Research contracts in recent years to develop and manufacture high performance food production systems for Earth and space, said Stoner.
Stoner is the principal investigator on a US$150,000 Small Business Technology Transfer research grant awarded in May by the National Science Foundation to AgriHouse to develop the new technology. Seelig is an institutional investigator on the effort. In 2006, Seelig was awarded a US$10,000 proof-of-concept grant for his research from CU's Technology Transfer Office.
Image: The new technology invented at the University of Colorado at Boulder involves tiny sensors clipped to plant leaves to wirelessly monitor the water needs of crops. It has been optioned to AgriHouse Inc. of Berthoud, Colo. Courtesy: AgriHouse Inc.
More information:
University of Colorado: CU-Boulder Invention May Allow Thirsty Crops To Signal Farmers - June 14, 2007
Seelig, Hans-Dieter, "The assessment of water deficit stress in plants using optical measurement methods", University of Colorado, Phd. Thesis, 2005.
Hans-Dieter Seelig, et. al, "Non-Contact Measurement Methods of Detecting Plant Water Deficit Stress for Space Flight Growth Chamber Application"[*abstract], SAE Technical Papers, Document Number: 2004-01-2455, January 2004.
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Thursday, June 14, 2007
Breakthrough in biorefining: scientists obtain high yields of HMF from sugar
Scientists from the Pacific Northwest National Laboratory (PNNL) took a giant step closer to efficient biorefining this week, reporting in the June 15 issue of the journal Science that they have directly converted sugars ubiquitous in nature to an alternative source for those products that make oil so valuable, with very little of the residual impurities that have made the quest so daunting.
No one else has been able to convert glucose directly in high yields to a primary building block for fuel and polyesters. Using a novel non-acidic catalytic system containing metal chloride catalysts in a solvent capable of dissolving cellulose, the scientists succeeded in extracting HMF, obtaining yields of 70% for glucose and almost 90% for fructose.
The building block HMF, which stands for hydroxymethylfurfural, is a chemical derived from carbohydrates such as glucose and fructose and is viewed as a promising surrogate for petroleum-based chemicals to make biobased polyesters, biofuels and many other products typical of the bioeconmy (image, click to enlarge).
Glucose, in plant starch and cellulose, is nature's most abundant sugar. But getting a commercially viable yield of HMF from glucose has been very challenging. In addition to low yield until now, the conversion process always generates many different byproducts, including levulinic acid, making product purification expensive and uncompetitive with petroleum-based chemicals.
Z. Conrad Zhang, senior author who led the research and a scientist with the PNNL-based Institute for Interfacial Catalysis (IIC), together with former post-doc Haibo Zhao, and colleagues John Holladay and Heather Brown, all from PNNL, were able to coax HMF yields upward of 70 percent from glucose and nearly 90 percent from fructose while leaving only traces of acid impurities.
To achieve this, they experimented with a novel non-acidic catalytic system containing metal chloride catalysts in a solvent capable of dissolving cellulose. The solvent, called an ionic liquid, enabled the metal chlorides to convert the sugars to HMF. Ionic liquids provide an additional benefit: it is reusable, thus produces none of the wastewater in other methods that convert fructose to HMF:
bioenergy :: biofuels :: energy :: sustainability :: biomass :: cellulose :: starch :: sugar :: glucose :: fructose :: polyester :: biopolymers :: renewable ::green chemistry :: biorefining :: bioeconomy ::
Metal chlorides belong to a class of ionic-liquid-soluble materials called halides, which in general work well for converting fructose to HMF but not so well when glucose is the initial stock. In fact, attempts at direct glucose conversion created so many impurities that it was simpler to start with the fructose, less common in nature than glucose.
Zhang and his team, working with a high-throughput reactor capable of testing 96 metal halide catalysts at various temperatures, discovered that a particular metal - chromium chloride - was by far the most effective at converting glucose to HMF with few impurities and, as such reactions go, at low temperature, 100 degrees centigrade.
The chemistry at work remains largely a mystery, Zhang said, but he suspects that metal chloride catalysts work during an atom-swapping phase that sugar molecules go through called mutarotation, in which an H (hydrogen) and OH (hydroxyl group) trade places.
The hydrogen-hydroxyl position-switch that allows the catalytic conversion was verified by nuclear magnetic resonance performed at the William R. Wiley Environmental Molecular Sciences Laboratory, a DOE national scientific user facility located at PNNL. During the swap, the molecule opens, Zhang said.
"The key is to take advantage of the open form to perform a hydride transfer through which glucose is converted to fructose."
Zhang's next step is to tinker with ionic solvents and metal halides combinations to see if he can increase HMF yield from glucose while reducing separation and purification cost.
"The opportunities are endless," Zhang said, "and the chemistry is starting to get interesting."
Image: Scientists have discovered the most effective method yet to convert glucose, found in plants worldwide and nature's most abundant sugar, to HFM, a chemical that can be broken into components for products now made from petroleum. Credit: Pacific Northwest National Laboratory
More information:
Eurekalert: Plastic that grows on trees - Fuel, polyester and other chemicals from biomass get a giant boost, PNNL team reports in the journal Science - June 14, 2007.
At the time of this release, the abstract for the article in Science was not yet available.
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