New preparations are a mixture of pesticides with biodegradable polymers. Polymers gradually degrade in the soil, and pesticides get slowly released and get exactly in the place where they were deposited.
Pesticides are hundreds of active substances and dozens of thousands of preparations. Contemporary pesticides are used in the form of powder and emulsions; under the influence of precipitations and wind they do not only get to their destination but also disperse at large areas thus contaminating environment.
Unfortunately, it is sometimes rather difficult to identify their presence in water, soil and air, besides little is known about toxic properties of multiple preparations and about consequences of their longstanding influence on the environment. For this reason contemporary pesticides are dangerous for people and environment. At that, they do not perform their immediate task – they do not protect plants from vermin, a lot of which have developed resistance to pesticides. Therefore, agriculture needs fundamentally new protection, which could enable address delivery of chemicals.
To this end, the pesticide is enclosed into a matrix made of biodegradable materials. The pesticide enclosed in such a matrix will not get into water or air, it will remain where it was deposited (“packed”) and will gradually release from the polymer carrier. In some countries, ethyl-cellulose, polyurethane and sodium alginate are already used for this purpose. The researchers from Krasnoyarsk suggest to use for pesticide depositing the polymer of microbiological origin actively degradable in the soil (copolymer of hydroxybutyrate and hydroxyvalerianate), which was synthesized at the Institute of Biophysics of the Earth (Russian Academy of Sciences). This polymer fully degrades under the influence of soil microorganisms, therefore it is not accumulated either in soil or in water and does not contaminate outskirts like plastic bottles do. Destruction takes place within several months, which allows to develop preparations of lasting action.
The researchers have tested two preparations. One of them, a complex action insecticide – a- hexachlorocyclohexane – is used to fight harmful insects and utilized for seed sterilization to protect sprouts from soil vermin. The other chemical – Lindane – is an efficient insecticide with a wide action spectrum. The preparations were mixed with well-milled powdery polymer, and tablets (which are 3 millimeters in diameter, their weight making 20-22 grams) were pressed out of obtained mixture. Preliminary weighed samples were deposited into the lawn-and-garden soil and kept there for 12 weeks at a definite temperature and humidity, periodically taking samples to determine remaining mass of the polymer and pesticide concentration in the soil.
Soil microorganisms perceived the polymer as a nutritious product and actively destroyed it. The bulk of the polymer was destroyed in the soil within 40 to 50 days since the begging of the experiment, by that time, there remained no more than 5% of head grade in the tablet. Pesticides got out of the tablets into the soil unhurriedly. During the first 30 to 40 days, no more than 2% to 3% of a-hexachlorocyclohexane was released, and in 70 to 80 days, the tablet was released of 10% to 12% of the preparation. The Lindane output, the content of which was higher in the polymer matrix, was about 30% by the end of the experiment.
By the example of two pesticides the researchers have proved that the preparations enclosed into a biodagragable polymer matrix are leaving it gradually, without abrupt discharges. By varying the polymer/preparation ratio, the researchers can regulate the rate of pesticide release into the soil.
Olga Myznikova | alfa
Filling intercropping info gap
16.11.2017 | American Society of Agronomy
Climate change, population growth may lead to open ocean aquaculture
05.10.2017 | Oregon State University
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses