Nitrates in plants and soil after fertilization of grass-legume mixtures

Abstract

Nitrates are one of the most frequent utilized forms of N from soil. Through root they reach stem and leaf where in photosynthetic processes they convert into proteins. Due to exposure to stress situations, and excessive nitrogen fertilization, nitrate accumulation in plant tissues and organs occurs. Also, nitrates can accumulate in harmful concentrations in soil. Nitrates accumulated in plants have harmful effect on animals which consume plants since they cause various health disorders. In variance analysis in both investigation years it was established that fertilization as well as interaction of factors mixture/fertilization had very significant effect on investigated quality parameter, contrary to mixture as single factor. In both investigation years, treatments with 210 kgN ha-1 had the highest nitrate concentration. Content of nitrate nitrogen in soil is increased by fertilization. Objective of the research was to determine nitrate quantities which are accumulated in plants subsequent to n fertilization and growing in mixtures with other species, as well as to determine nitrate quantities which remain in the soil unutilized, which are potential causes of environment pollution.

Nitrati su jedan od najčešće usvajanih oblika N iz zemljišta. Preko korena oni dospevaju do stabla i lista gde se fotosintetičkim procesima konvertuju u proteine. Usled izloženosti stresnim situacijama, kao i preteranim đubrenjem azotnim đubrivima, dolazi do nagomilavanja nitrata u tkivima i organima biljaka. Pored toga oni se mogu nakupljati u štetnim koncentracijama i u zemljištu. U biljkama nagomilani nitrati imaju štetnog uticaja na životinje, jer ishranom, izazivaju različite zdravstvene poremećaje. Analizom varijanse u obe godine ispitivanja utvrđeno je da su đubrenje kao i interakcija faktora smeša/đubrenje imali vrlo značajnog uticaja na ispitivani parametar kvaliteta, za razliku od smeše kao pojedinačnog faktora. U obe ispitivane godine tretmani sa 210 kgN ha-1 imali su najveću koncentraciju nitrata. Sadržaj nitratnog azota u zemljištu povećava se đubrenjem.Cilj istraživanja je da se utvrdi koje su to količine nitrata koje biljka akumulira nakon đubrenja N đubrivom i gajenjem u smeši sa drugim vrstama, kao i koje su to količine nitrata koje ostaju u zemljištu ne iskorišćenje, a koje mogu biti potencijalni zagađivači životne sredine.