1

National University of Life and Environmental Sciences of UkraineDepartment of Ecology and Sustainable Development

MASTER’S WORKabout:

“Ecotoxicological assessment of environmental quality for the mathematical models in the system “soil-plant””

Made by _______________________________________О.S. BilobrovaSupervisors : канд.с.-г.наук____________________________Т. С. Кіщак

д.с.-г.н.,проф.__________________________В.М. Кавецький

Kiev – 2012

Primary goal :

Summary of major existing mathematical models that describe the processes of

circulation and behavior of pollutants in biocenose and demonstrate their use with

examples of experimental results.

2

3

Main tasks:

•Summarize the modern principles of modeling the behavior of pollutants in the system "soil-plant" and get a system of mathematical relationships describing the behavior of pollutants in the environment.•To investigate the possibility of using mathematical models to assess the quality of the environment.•To demonstrate the practical use of these models by the example of the original experiments.

4

Materials and Methods:

Field experiments were conducted at the Chernihiv Institute APV UAAS;sampling was conducted in accordance with generally accepted techniques;determination of glyphosate in the grain of winter wheat were carried out by thin layer chromatography;•agricultural technology common to the conditions of soil and climate zone;•used winter wheat varieties Myronivska;•phosphorus fertilizer Ahrofoska;•herbicide (as desiccant) glyphosate.

5

Basic mathematical models that describe the processes in open systems biocenosis:

•Kinetics of degradation of substances in the system "soil-plant“;•Probit Analysis;•Michaelis-Menten equation;•Calculation Agro-Ecotoxicological Index of applying hazard of pesticide.

6

Kinetics of destruction substances in system "soil-plant"

Half Life - T50, the time during which the pesticide content in the object that is studied, reduced by 50%.To calculate the T50 used a model that reflects the processes of degradation of toxic substances in any medium, provided constant rate of decay.Constant (k) is calculated by the formula:

                                   K =

where t - time (day)Co and Ct - pesticides in the initial moment of time interval t (mg / kg).Knowing constant (k), half-life (T50) is determined by the formula:

                                      T50 =

Kinetics of detoxification glyphosate in winter wheat

7

8

Kinetics of detoxification glyphosate in winter wheat

9

Evaluation of hazard substances by the method of "dose-effect“

Probit Analysis

10

Determination of toxicity of pesticides by the statistical method of "dose-effect" (for example research influence the toxicity of pesticides on Daphnia

(Daphnia magna))

Michaelis-Menten equation:

11

12

Agro Ecotoxicological Index:

13

Calculation AETI an example application of glyphosate in winter wheat

According to the references, glyphosate has hazard class - 3 in category A and hazard class - 4 in category B. Using an integrated

classification of pesticides, it was found that glyphosate has a degree of danger - 6.

Average degree of hazard was calculated by the formula:Q = Co1m1 / M = 6 * 3/3 = 6,where Co = 6, m and M = 3,

  because glyphosate was applied 3 kg / ha.

Ecotoxicological dose was calculated by the formula   Dekm = M / S = 3/1 = 3,

where S - the total arable area equal to one hectare.

14

Index purification land, Polissya zone sodpodzolic typical and gleyed soils is  Iso= 0.5 according to the handbooks of literature.Integral indicator pesticide agricultural landscape was calculated by the formula: 

V = Dekt / Q * Ico = 3/6 * 0.5 = 1

Then AETI = 10V (1 + V) 3 / (1 + V) 4 + 5000 =

= 10 * 8/5016 = 0.02

We can conclude that Glyphosate is a little dangerous substance.

15

CONCLUSIONS:

Assessment of environmental quality is to use methods of physico-chemical monitoring, a comprehensive assessment of the quality of the ecosystem through mathematical modeling, which are based on the laws toxicodynamics, toxicokinetics and statistics and conduct search integrated methods for assessing the quality of ecosystems as a whole on the basis of most living organisms and their communities. In the thesis work the synthesis of modern principles of modeling behavior of pollutants in the soil plant.

1. It is shown that the inhibition of peroxidase different potato varieties to pathogens is well described by Michaelis-Menten equation. In applying the pathogen, Michaelis constants in both potato varieties changed (in resistant varieties Km decreased from 8.9 to 3.1 in the sensitive variety Km decreased from 21.3 to 2.1). This makes it possible to predict the aggressiveness of the pathogen.

16

3. Kinetics detoxify glyphosate used to desication winter wheat and influence on the rate of detoxification of modern phosphate fertilizers. In the experiment, the rate constant k (day-1) collapse of glyphosate for the control was 0.19, for version with superphosphate - 0.25, the version with ahrofoskoyu - 0.32, and the half-life (T50 = 0,693 / k) respectively is : 3.6, 2.7, 2.2 days. That glyphosate fastest splits into variants were introduced where phosphate fertilizers (ahrofoska and superphosphate).4. Defined Agro Ecotoxicological Index risk of use glyphosate when growing winter wheat, which is 0.02 mg / kg and thus there is little danger.5. It is shown that the use of mathematical modeling facilitates risk assessment of pollutants in biocenosis components and their effect on the metabolism of living organisms and the environment.6. Further study and generalization of mathematical modeling of the behavior of pollutants in the environment can be used as a development and writing handbook for laboratory studies of Ecotoxicology to facilitate their application in practice environmental experts.

Thank you for your attention

17