N.Yu. Konovalov, P.P. Gonchar-Zaikin, O.S. Zhuravlev
The paper deals with some theoretical and applied aspects of the mathematical modelling while studying the ecological mechanisms of organic matter transformation in the organomineral root medium, ORM, of the natural and technogeneous agroecosystems. The wide interpretation of the agroecological factor used within the scope of this paper is based on the knowledge that a decomposition and a synthesis of organic matter in ORM are almost completely carried out by the activity of rhizobiota. Therefore all factors determining the microbial activity are included in the conception of the agroecological factor in this case, i.e. biotic, abiotic (temperature, humidity, acidity, salt contents etc.) and environmental.

At different hierarchic levels there are complicated interactions among the elements of the agroecosystem in question. The organic matter transforming in ORM has a heterogeneous composition and different availability for the various groups of microorganisms. The system is not isolated and has an exchange with an environment. The external effects of abiotic, biotic and anthropogenic nature influence the rates of intrasystem processes. There are regulated or inspected effects: a type, quantites and a time of application of organic materials, a variety and yield of cultivated plants, a type of soil (substrate) cultivation. The dynamics of the organic matter content and its fractions in ORM may be treated as the inspected responses of the agroecosystem. Thus, we face a complex system according to the rigorous definition from system analysis.

We have considered all possible elements of the agroecosystem taking part in the transformation of the organic matter in ORM, then we shall deal with the II functional groups as the most significant: 4 groups of organic compounds with different complexity of composition, 5 groups of microorganisms (autotrophs, 3 groups of heterotrophs - 2 of them secrete different enzymes catalyzing the splitting of high molecular organic substrates, and Protozoa predating on the other groups), 2 above mentioned groups of enzymes.

In order to describe the dynamic of the simulated system components in the mathematical form we use the well-known equations for the microbial growth on the given substrate, for the choosing of the favourite substrate, for the consideration of the competition and the prev-predator interactions, for the kinetics of the enzymatic splitting of the high molecular substrates. The equations were combined into the general model.

It is possible to observe the evolution of all system components knowing initial conditions and exchange flows of carbon.

The analysis of the model has given us the following results.

  1. The dynamics of the activity, numbers and composition of the microbial populations are mainly determined by the quantity and contents of the organic substrates.
  2. The ratio and the levels of the organic matter components in ORM depend on the total concentration of saprophytes, and the part
Konovalov, N.Yu., Gonchar-Zaikin, P.P. and Zhuravlev, O.S. (1988). THE BIOPHYSICAL ASPECTS OF THE ORGANOMINERAL ROOT MEDIUM AGROECOLOGY. Acta Hortic. 229, 271-272
DOI: 10.17660/ActaHortic.1988.229.28

Acta Horticulturae