| Summary: | Since their discovery to the present day, pesticides have been an inevitable segment of agricultural production and efforts have been made to synthesize compounds that would share a required efficacy along with selectivity, sufficient persistence on the object of protection and favourable toxicological and ecotoxicological characteristics so as to minimize their effect on the environment. When a pesticide gets into soil after application, it takes part in a number of physical, chemical and biological processes that depend not only on the compound itself, but a number of other factors as well, such as: physical, chemical and biological characteristics of soil; climatic factors, equipment used, method of application, method of storage, handling and disposal of waste, site characteristics (proximity of ground and underground waters, biodiversity and sensitivity of the environment). Microorganisms play an important role in pesticide degradation as they are able to utilize the biogenic elements from those compounds, as well as energy for their physiological processes. On the other hand, pesticides are more or less toxic substances that can have adverse effect on populations of microorganisms and prevent their development, reduce their abundance, deplete their taxonomic complexity and create communities with a lower level of diversity and reduced physiological activity. The article discusses complex interactions between pesticides and microorganisms in soil immediately after application and over the ensuing period. Data on changes in the abundance of some systematic and physiological groups of microorganisms, their microbial biomass and enzymatic activity caused under pesticide activity are discussed as indicators of these processes. Od otkrivanja pa do danas, pesticidi su ezaobilazni segment poljoprivredne proizvodnje, a u njihovom razvoju teži se ka sintezi jedinjenja koja će imati potrebnu efikasnost i selektivnost, dovoljnu dužinu zadržavanja na objektu i povoljne toksikološke i ekotoksikološke karakteristike, kako bi imali što manji neželjeni uticaj na životnu sredinu u celini. Kad se nakon primene nađe u zemljištu, pesticidno jedinjenje biva izloženo brojnim fizičkim, hemijskim i biološkim procesima razgradnje koji zavise ne samo od osobina jedinjenja, već i od čitavog niza drugih faktora, kao što su: fizičke, hemijske i biološke karakteristika zemljišta i klimatski faktori. U procesima razgradnje pesticida u zemljištu značajnu ulogu imaju mikroorganizmi, imajući u vidu da su sposobni da iz njihovih molekula koriste biogene elemente i energiju za svoje fiziološke procese. S druge strane, pesticidi koji su sami po sebi manje ili više toksične supstance, mogu štetno da deluju na populacije mikroorganizma i da dovedu do zaustavljanja njihovog razvoja, smanjenja brojnosti, osiromašenja taksonomskog sastava, stvaranja zajednica sa nižim stepenom raznovrsnosti i smanjenom fiziološkom aktivnošću. U ovom radu razmatraju se uzajamni procesi i odnosi koji se uspostavljaju u zemljištu između pesticida i mikroorganizama neposredno, kao i u periodu posle primene. Kao pokazatelji ovih procesa dati su podaci o promeni brojnosti pojedinih sistematskih i fizioloških grupa mikroorganizama, mikrobiološke biomase i aktivnosti enzima koji su nastali pod uticajem pesticida.
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