Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Growstones ideal alternative to perlite, parboiled rice hulls

15.12.2011
Substrate made from waste glass performs well in greenhouse applications

In the greenhouse business, organic and inorganic growing substrates are chosen for the physical and chemical properties necessary to support specific crops and growing conditions. One important physical property in substrates is air-filled pore space, a particularly important characteristic that allows for gas exchange between plants' roots and the outside atmosphere.

Perlite and parboiled rice hulls are the two of the most common components used to increase air-filled pore space (AFP) in substrates. A study compared these popular components to Growstones, an aggregate produced from finely ground waste glass.

Although they are widely used in horticulture applications, both perlite and parboiled rice hulls have disadvantages and limitations. Perlite, a natural glass of volcanic origin that expands when quickly heated, has become increasingly expensive due to costs of mining, transportation, and production. In addition to its rising price tag, perlite produces a siliceous dust that is an eye and lung irritant. Parboiled rice hulls (PBH) are produced only in specific areas of the United States, making high shipping costs an issue for end-users. And, because it is a plant-based component, PBH may also have limitations with respect to its use in long-term crops because of softening and decomposition.

Michael R. Evans, Professor in the Department of Horticulture at the University of Arkansas, created experiments to compare perlite and PBH with Growstones. Evans' results were published in HortTechnology. According to Evans, aggregates such as Growstones (produced by Earthstone Corp., Santa Fe, NM) have been proposed as alternatives to perlite and PBH to adjust the physical properties of peat-based substrates.

Growstones, which have been successfully used as a hydroponic substrate, are produced from finely ground waste glass. The ground glass powder is combined with calcium carbonate and heated in a kiln. Carbon dioxide is produced as the glass particles are heated and fused together, trapping air spaces inside the glass. The result is an expanded, lightweight product that is cooled before being ground to the desired size.

Evans' experiments showed that Growstones had an AFP higher than that of both peat and perlite. Additionally, when added to peat at a concentration of at least 15%, Growstones increased the AFP of the resulting peat-based substrate.

"Growstones can be used in a similar manner to perlite and PBH as an aggregate to increase AFP of peat based substrates", Evans said. "The primary differences were that, at concentrations of 25% or more, GS resulted in a higher AFP than equivalent perlite-containing substrates. Also, substrates containing 20% or more GS had a higher water-holding capacity than equivalent perlite- and PBH-containing substrates, and GS-containing substrates had a higher bulk density than equivalent perlite- and PBH-containing substrates."

All GS-containing substrates had physical properties within recommended ranges. Vinca, impatiens, and geranium plugs grown in GS-containing substrates were comparable to plants grown in equivalent perlite- and PBH-containing substrates.

Evans said that the experiments showed that Growstones can be successfully used as a component for substrates used in greenhouse crop production.

The complete study and abstract are available on the ASHS HortTechnology electronic journal web site: http://horttech.ashspublications.org/cgi/content/abstract/21/1/30

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education, and application.

Michael W. Neff | EurekAlert!
Further information:
http://www.ashs.org

More articles from Agricultural and Forestry Science:

nachricht New parsley virus discovered by Braunschweig researchers
17.05.2019 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH

nachricht Franco-German research initiative on low-pesticide agriculture in Europe
16.05.2019 | Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V.

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: The geometry of an electron determined for the first time

Physicists at the University of Basel are able to show for the first time how a single electron looks in an artificial atom. A newly developed method enables them to show the probability of an electron being present in a space. This allows improved control of electron spins, which could serve as the smallest information unit in a future quantum computer. The experiments were published in Physical Review Letters and the related theory in Physical Review B.

The spin of an electron is a promising candidate for use as the smallest information unit (qubit) of a quantum computer. Controlling and switching this spin or...

Im Focus: Self-repairing batteries

UTokyo engineers develop a way to create high-capacity long-life batteries

Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...

Im Focus: Quantum Cloud Computing with Self-Check

With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.

Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...

Im Focus: Accelerating quantum technologies with materials processing at the atomic scale

'Quantum technologies' utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing.

However a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been...

Im Focus: A step towards probabilistic computing

Working group led by physicist Professor Ulrich Nowak at the University of Konstanz, in collaboration with a team of physicists from Johannes Gutenberg University Mainz, demonstrates how skyrmions can be used for the computer concepts of the future

When it comes to performing a calculation destined to arrive at an exact result, humans are hopelessly inferior to the computer. In other areas, humans are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Plumbene, graphene's latest cousin, realized on the 'nano water cube'

23.05.2019 | Materials Sciences

New flatland material: Physicists obtain quasi-2D gold

23.05.2019 | Materials Sciences

New Boost for ToCoTronics

23.05.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>