Possibility of water and nutrient retention increase in agricultural landscape on example of Třeboňsko area is subject of PhD thesis presented here by Mgr. Richard Lhotský. PhD thesis is divided into three main chapters that try to answer three basic questions: 1. How far is possible to increase landscape water retention using fishponds? 2. Large amount of nutrient and soil leach arable land, both causing surface water euthrophication and a bigger sedimentation in fishponds. Is it possible to moderate these harmful effects? 3. If wetlands became a part of landscape features how to utilize plant biomass from these areas. Fishponds or even whole fishpond system is a specific component of czech rural landscape and fulfill several important functions. Water accumulation and retention are the most important considering the thesis ? fishponds collect water from a catchment area and also collect floodwaves. Current agriculture based on originally steppe crop needs amelioration. In spite lot of positive features we have to bear in mind that water drainage systems increase mineralization of an organic matter in soil and nutrient loss which might be economically important as well as decrease of surface water quality due to the euthphication. Wetlands and small water bodies (fishponds) may play important role as a nutrient trap in agricultural catchment areas, reuse them and prevent their loss from a landscape and whole Czech Republic. It is necessary to solve a utilization of plant biomass from nutrient and water retention areas and use that in biogas plants seems to be one of the most promising.

This diploma theses focuses on comparison of natural and intentionally inducated supressiveness of environment induced by application of entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, Isaria fumosorosea a Lecanicillium muscarium. In tests were evaluated the in vitro parameters as well as the effectiveness in vivo biotests on insect host larva Tenebrio molitor. The species of entomopatoghenic fungi were applied in suspensions, single strains and also in combination of two strains. In the in vitro conditions the possibilities of objective evaluation of the supresivity level were tested by using the CFU test (Colony Forming Units) on three different nutrient media (PDA, PDA + A , PDA + D), as one of the basic evaluation parameters. Further the germination tests were evaluated according to GI (Germination Index), determination of radial growth (comparison of median cultures) and interaction of strain suspensions on nutrient media PDA. In the in vivo biotests were watched the epizooties from suspensions of these entomopathogenic fungi on insect larva Tenebrio molitor in competitive test of strains according to FDI (Fungl development index) evaluation scala. Chosen larva covered by fully sporulating mycelium from epizootie were further evaluated in CFU test. The result were dominant strain/s on the larva from applied suspensions.

This thesis deals with assessment of two small water courses Leskava and Troubsky brook. Streams are evaluated from two aspects: content of three forms of phosphorus TP, Panorg and Porg and hydromorphological assessment. Total phosphorus was determined by sample mineralization by H2SO4+H2O2. Pinorg and Porg were determined by a method published by Pardo. Hydromorphological assessment was done by methodology Králová at al.