Scientific staff:
Susanne E lm holt: T he effect of pesticides on the m icroflora G itte Felding: D eterm ination of leaching of pesticides A rn e Helweg: D egradation of pesticides, etc. in soil E rik Kirknel: Fungicides and insecticides in plants P e d er O dgaard: H erbicides in plants
T he laboratory supports the experim ental w ork at different departm ents at the research centre with chemical analysis of pesticides. F urtherm ore, the d ep artm en t is using increasing resources on terrestrial environm ental research. The m ain objective is determ ination of the fate of pesticides in the terrestrial environment and the environm ental consequences of the use o f pesticides. T he experiments are carried out by m eans of advanced chemical and biological m ethods an d the main tasks a re the following:
1. C arry out residue analysis of pesticides in crops and soils in cooperation with the experim ental work at the centre.
2. D eterm ine degradation, adsorption and transport of pesticides in soil.
3. Analyse infiltrated w ater to determ ine the risk of leaching of pesticides out of the root zone.
4. D eterm ine the influence of pesticide treatm ent on soil microorganisms.
5. Participate in determ ination of pesticide tran sp o rt and deposition during spraying and determ ine exposure o f spraying personnel to pesticides.
The laboratory is equipped with analytical instrum ents: gaschrom atographs w ith EC, NP, H W and F P D -detectors and gaschrom atograph w ith m assspectrom eter. To determ ine drift o f pesticides fluorescent com pounds are used, these are determ ined by fluorom etry, and to determ ine adsorption and degradation C-labelled com pounds are mostly used. T hese are determ ined by scintillation counter.
T he staff consists of 5 scientists, 6 technicians and 2 to 4 MSc-students.
FIELD AND LABORATORY INVESTIGATIONS
The effect of fungicides on the fungal flora and on the decomposition of straw in soil (S u sa n n e Elmhnltl
In 1987, a determ ination to species has been m ade o f a large num ber of isolates of Penicillium and an identification of residue concentrations o f fungicides in soil (E.
Kirknel). In 1987, a sm all field experim ent with Tilt and subsequent investigations of the biomass, m icrobial activity, decom position o f organic "model" substance (gelatine) and straw was conducted. A degradation of straw will b e carried out in a "litter-bag"
experim ent. T herefore, it has been necessary to conduct prelim inary experim ents to adjust the qualitative m ethods to the "litter-bag" m ethod. F urtherm ore, the influence of various fungicides on the decom position of ^ C -la b e lle d straw was m easured.
Determination of pesticides in groundwater and drain water (Gitte FeMinp)
In collaboration w ith the T he D anish Geological Survey and local extension officers we have selected hom ogeneous coarse sandy soils with a high level of groundw ater.
Samples were taken n ear Ølgod and Løgum kloster. G oundw ater sam ples w ere taken below 2 maize fields, one o f which has been sprayed with atrazine for th ree successive years, the other for about 10 years. The content o f atrazine, desethylatrazine and desisopropylatrazine was analyzed in the groundw ater. Soil samples, about 10, were taken from the soil surface down to the groundw ater level and analyzed for possible content of atrazine to study w hether a "front" is passing down through the soil to the groundwater.
Pesticide learhinp (Gitte Felding and Arne Helweg')
In collaboration w ith T he D anish Geological Survey and local extension officers we have selected som e heavy clay soils grown with beet and w inter barley and some clayish forest soils w ith conifers. In order to m easure pesticide leaching from the root zone perforated tu b es - 3 per locality - were placed to collect the w ater leaving the root zone. T he tu b es w ere em ptied during winter, and hexazinon, atrazine, phenoxyherbicides and carbofuron occurrence was determ ined by the G C /M S m ethod.
Degradation and effect of pesticdes in soil (Arne Helwegl
A series of experim ents m easuring the degradation and adsorption of M CPA, dichlorprop, 2.4-dichlorophenol, TC A and parathion in soil sam ples taken below the root zone have b een finished. T he results showed a degradation rate o f about 1/10 of the rate in surface soil. D eterm ination of the com position o f the soil air to the depth of 2 m has also b ee n finished. A lso the influence of soil tem p eratu re and w ater content on the degradation of M C PA was analyzed in soil from the plough layer.
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Insecticides, fungicides and growth regulators in plants (Erik Kirknel-)
In collaboration with the N ational Institute of A nim al Science the effect o f growth regulators (C erone) on residues in anim al products and on reproduction was determ ined. M ethods o f analysis w ere prepared.
In collaboration with the G overnm ent Bee R esearch Service investigations w ere m ade to study w hether insecticides are brought into the hives. Bees, honey, larvae, wax and pollen was analyzed for pesticide residues.
M etam -N a in soil was analyzed.
Spray technical experim ents with fluorescent tracer com pounds were perform ed in clim ate cham bers and in the field.
W inter crops w ere analyzed from autum n to spring for residues of prochloraz to support an evaluation of the im portance of tim ing o f application.
Herbicides, etc. in plants, soil and water fPeder Odgaard)
Analyses w ere m ade o f grow th regulators in nutrient solutions from irrigation systems.
T he purpose was to reveal w hether the grow th regulators remain in the nutrient solutions making it possible to give advice about their re-use, even in o ther cultures.
U p to now ancymidol (Reducym ol) has been analyzed.
In spray technical experim ents perform ed in the field (deposition on plants and wind drift) a considerable num ber of m easurem ents have been carried out with fluorescent tracer. In this connection a com parison was perform ed o f objects used to collect spray liquid to control the applied quantity per area unit.
To b e able to m ake routine analyses of residual herbicide on the plant surface in a large num ber of experim ental plots (pot experim ents) it is necessary to have fast m ethods o f analysis. O n e of the herbicides currently being investigated is the wild oat difenzoquat (Avenge). A n operative m ethod has been found for this com pound.