Agricultural Impact on Groundwater Vulnerability to Nitrate in Northern Croatia

There is noticeable negative impact on soil and water quality caused by nutrient leaching, especially nitrate. Five regions in Croatia are preliminary delineated as nitrate vulnerable zones, including potentially vulnerable zones (PVZ) and vulnerable zones (VZ), one of them being Varaždin County. Agricultural land spreads on 59% of its total area. The survey was carried out to analyze two available land use databases, ARKOD and CLC 2006, to determine relation between land use and vulnerability to nitrate. Results of on-going groundwater, soil and percolate research (nitrate concentrations) in the same area are used for more precise nitrate vulnerability determination. Database analysis revealed no significant difference in land use within VZ and PVZ. Groundwater monitoring shows no consistency between nitrate concentrations and PVZ/VZ designation. Furthermore, the difference in the amount of residual soil nitrogen in two years of research was determined. Results of lysimeter study show that up to 32% of applied nitrogen is percolated to deeper soil layers indicating high agricultural impact on groundwater vulnerability to nitrate

Analysis of Climate Elements in Central and Western Istria for the Purpose of Determining Irrigation Requirements of Agricultural Crops

A consequence of climate changes is an increasing frequency of drought, which on average occurs in Croatia every third to fifth year and during the vegetation period it can reduce crop yield significantly. The aim of the research is both to determine crop water requirements in an average and in a dry year and to determine the decline in crop yields in an average and in a dry year. The multi-annual climate data series for a 30-year period, 1981-2010 from station Pazin in central Istria and 1981-2010 from Poreč in western Istria was used. Based on these data, a reference evapotranspiration was calculated for an average and a dry year using the Penman-Monteith method through "Cropwat" software. The crop water requirement for five different crops is determined by soil water balance using the Palmer method (Palmer, 1965), corrected according to Širić and Vidaček (1988), using "Hidrokalk" software. Crop response to the lack of soil water and yield decline were determined according to the method published by Doorenbos and Kassam (1979). Correlation test was used to determine correlation between precipitation and crop yields. In central Istria, water shortage in an average year ranged from 3.4 mm (olives) to 110.7 mm (alfalfa) and yield decline ranged from 1.1% (olives) to 18.6% (alfalfa), while in a dry year water shortage ranged from 43.2 mm (olives) to 229.5 mm (alfalfa) and ranged from 10.3% (olives) to 37.7% (alfalfa). In western Istria, in an average year water shortage ranged from 35.5 mm (olives) to 239.7 mm (alfalfa) and yield decline ranged from 7% (olives) to 40.2% (tomatoes), and in a dry year water shortage ranged from 74.4 mm (olives) to 288.9 mm (alfalfa) and yield decline ranged from 14.4% (olives) to 40.7% (alfalfa). The determined water shortage and reduced yields are sufficient indicators of irrigation requirements in Istria

Analysis of Climate Elements in Central and Western Istria for the Purpose of Determining Irrigation Requirements of Agricultural Crops

A consequence of climate changes is an increasing frequency of drought, which on average occurs in Croatia every third to fifth year and during the vegetation period it can reduce crop yield significantly. The aim of the research is both to determine crop water requirements in an average and in a dry year and to determine the decline in crop yields in an average and in a dry year. The multi-annual climate data series for a 30-year period, 1981-2010 from station Pazin in central Istria and 1981-2010 from Poreč in western Istria was used. Based on these data, a reference evapotranspiration was calculated for an average and a dry year using the Penman-Monteith method through "Cropwat" software. The crop water requirement for five different crops is determined by soil water balance using the Palmer method (Palmer, 1965), corrected according to Širić and Vidaček (1988), using "Hidrokalk" software. Crop response to the lack of soil water and yield decline were determined according to the method published by Doorenbos and Kassam (1979). Correlation test was used to determine correlation between precipitation and crop yields. In central Istria, water shortage in an average year ranged from 3.4 mm (olives) to 110.7 mm (alfalfa) and yield decline ranged from 1.1% (olives) to 18.6% (alfalfa), while in a dry year water shortage ranged from 43.2 mm (olives) to 229.5 mm (alfalfa) and ranged from 10.3% (olives) to 37.7% (alfalfa). In western Istria, in an average year water shortage ranged from 35.5 mm (olives) to 239.7 mm (alfalfa) and yield decline ranged from 7% (olives) to 40.2% (tomatoes), and in a dry year water shortage ranged from 74.4 mm (olives) to 288.9 mm (alfalfa) and yield decline ranged from 14.4% (olives) to 40.7% (alfalfa). The determined water shortage and reduced yields are sufficient indicators of irrigation requirements in Istria

Mehanizmi toksičnosti ionskih kapljevina

Over the past three decades a growing awareness of environmental protection prompted the development of so-called green and sustainable technologies. Therefore, academic and wider community intensively explores new chemicals and safer, more energy efficient processes based on a rational compromise between economic, social, and environmental requirements. Due to low volatility and stability, ionic liquids emerged as a potential replacement for traditional volatile and harmful organic solvents. Various studies have been carried out to validate the green character of ionic liquids, whereby data published suggest that these compounds, due to their relatively high toxicity and poor biodegradability, could have an extremely negative impact on the environment. This paper presents the current knowledge on the toxicity of ionic liquids, with a special emphasis on the mechanisms by which this group of compounds causes changes in the morphology and physiology of organisms at different organisational levels of the ecosystem.U protekla tri desetljeća sve više raste svijest ljudi o potrebi zaštite okoliša, pa se velika pozornost pridaje tzv. zelenim i održivim tehnologijama. Stoga se u akademskim sredinama, a i u široj zajednici, intenzivno istražuju nove kemikalije te sigurniji i energetski učinkovitiji procesi koji se zasnivaju na prihvatljivom kompromisu između ekonomskih, socijalnih i ekoloških zahtjeva. Ionske se kapljevine zbog neznatne hlapljivosti i stabilnosti smatraju potencijalnom zelenom zamjenom za tradicionalna i škodljiva organska otapala. Kako bi se potvrdio zeleni karakter ionskih kapljevina, posljednjih godina provode se različita istraživanja njihova učinka na okoliš. Do sada objavljeni podaci upućuju na to da bi ova skupina spojeva, zbog relativno visoke toksičnosti i slabe biorazgradljivosti, ipak mogla imati izrazito negativan utjecaj na okoliš. U ovom radu prikazana su dosadašnja saznanja o toksičnosti ionskih kapljevina, s naglaskom na mehanizme kojima ova skupina spojeva uzrokuje promjene u morfologiji i fiziologiji organizama koji se nalaze na različitim organizacijskim razinama ekosustava

Primjena kultura stanica za određivanje biološke aktivnosti spojeva iz biljaka

Prirodni proizvodi poput žitarica, orašastih plodova, voća, povrća i ljekovitog bilja sadrže brojne biološki aktivne tvari (fenolne spojeve, glukozinolate, karotenoide, alkaloide i dr.) koje mogu imati različite povoljne, ali i nepovoljne učinke na organizam. Povoljni učinci na zdravlje ljudi povezuju se s antitumorskim, antialergijskim, antibiotičkim, antioksidacijskim i drugim svojstvima koje mogu posjedovati biološki aktivne tvari iz biljaka. Utvrđeno je da djelovanje navedenih tvari ima zaštitni učinak kod širokog raspona tumorskih oboljenja, smanjuje mogućnost pojave koronarnih bolesti, srčanog udara te štiti organizam od oksidativnog stresa uzrokovanog slobodnim radikalima. Stoga se sve više ispituje primjena biološki aktivnih tvari iz biljaka kao izvora novih lijekova, pri čemu se u istraživanjima često koriste in vitro testovi koji uključuju uporabu različitih humanih staničnih linija. Stanične linije koriste se u procjeni toksičnosti kemikalija i uzoraka iz okoliša te predstavljaju vrlo koristan alternativni pristup u (eko)toksikološkim istraživanjima. Također, često se koriste pri ispitivanju biološke aktivnosti spojeva prisutnih u biljkama, osobito voću i povrću, te raznih proizvoda koji se baziraju na tim sirovinama. Interakcija ispitivane tvari i bioloških sustava odvija se ponaprije na staničnoj razini, na čemu se temelji primjena in vitro staničnih kultura, koje omogućuju brže i ekonomičnije studije u odnosu na in vivo istraživanja. Kod in vitro testova najčešće se određuje tzv. bazalna citotoksičnost, kojom se određuje učinak ispitivane tvari na preživljenje stanica u kulturi, a tako dobiveni rezultati mogu poslužiti kao smjernice za daljnja in vivo istraživanja

Glucosinolates potential role in plant defence

Glukozinolati su složena klasa spojeva tioglukozidne strukture svojstvena biljkama porodice Cruciferae, u koju ubrajamo značajne kulture kao što su uljana repica, kupus, cvjetača, brokula, koraba, kelj, hren, gorušica. Sve biljke koje sadrže glukozinolate sadrže i endogeni enzim hidrolize - mirozinazu (β-tioglukozid-glukohidrolaza, EC 3.2.1.1) u odijeljenim dijelovima biljke. Oštećenjem tkiva oni dolaze u kontakt s enzimom mirozinazom te ovisno o strukturi glukozinolata nastaju različiti biološki aktivni produkti razgradnje, koji imaju čitav niz bioloških svojstava, od toksičnih do antikarcinogenih. Udio i sastav glukozinolata razlikuje se između biljnih vrsta te izmedu sorata istih vrsta te se mogu razlikovati unutar biljne jedinke ovisno o stupnju razvoja i vrsti organa. Različiti uvjeti okoliša u kojima se biljka nalazi, kao što su svjetlo, nutritivni status biljke, mehaničko oštećenje, infekcija fitopatogenima i oštećenja uzrokovana napadom insekata, mogu uzrokovati značajne promjene u sastavu i udjelu glukozinolata. Stoga postoji niz teorija o potencijalonoj ulozi glukozinolata u biljci, iako se njihova uloga u obrani biljke od insekata i fitopatogena smatra primarnom.Glucosinolates are sulfur- and nitrogen-containing plant secondary metabolites common in the Brassicaceae and related plant families. In the plant, they coexist with an endogenous β-thioglucosidase (EC 3.2.3.1) called myrosinase and upon plant tissue disruption, glucosinolates are released at the damage site and become hydrolyzed by myrosinase. The chemical nature of the hydrolysis products depends on the structure of the glucosinolate side chain, plant species and reaction conditions. Glucosinolate pattern differs between species and ecotype as well as between and even within individual plants, depending on developmental stage, tissue and photoperiod. A number of environmental conditions such as light plant, nutritional status, fungal infection, wounding and insect damage can alter the glucosinolate pattern significantly. The change of the glucosinolate profile by several environmental factors has brought forward different theories regarding their potential roles in the plant. However, the most accepted theory is that the glucosinolate-myrosinase system is involved in defense against herbivores and pathogens

Bioactive compounds glucosinolates and polyphenols in florets, leaves and stems of broccoli (Brassica oleracea var. italica L.)

Brokula (Brassica oleracea var. italica L.) je povrće koje se smatra izvornim oblikom cvjetače, a uzgaja se zbog zelenih cvjetnih izdanaka smještenih na razgranatoj mekanoj stabljici. Brokula je bogata bioaktivnim spojevima, glukozinolatima i polifenolima te se uvelike istražuje radi njihova korisnog djelovanja na ljudsko zdravlje. U literaturi je mnogo više radova o sastavu i udjelima bioaktivnih spojeva u cvatu nego u listovima i stabljici biljke. U ovom radu analizirani su ukupni i pojedinačni glukozinolati, ukupni polifenolni spojevi te njihov antioksidacijski kapacitet u svim jestivim dijelovima brokule (cvat, listovi, stabiljka). Utvrđeno je da je količina glukozinolata najveća u listu brokule pri čemu udio indolnih prevladava nad alifatskim spojevima što vrijedi i za cvat. U stabljici je veći udio alifatskih spojeva. Udio polifenolnih spojeva u uzorcima u rasponu je od 9,70-16,11 mg GE g-1 s. tv. u stabljici, od 17,65-31,08 mg GE g-1 s. tv. u cvatu i od 22,27-34,02 mg GE g-1 s.tv. u listu brokule. Veću antioksidacijsku aktivnost pokazuju uzorci s većom koncentracijom polifenola. Ti rezultati upućuju da ne samo cvat brokule već i ostali dijelovi biljke mogu biti vrijedan izvor bioaktivnih spojeva te ih se preporuča također koristiti u prehrani. Nadalje, nusproizvodi nakon berbe, stabiljke i listovi mogli bi se koristiti kao sirovina za njihovu izolaciju te eventualnu uporabu kao dodataka prehrani.Broccoli is rich in bioactive compounds, polyphenols and glucosinolates, and as such considered as functional food and great experimental material. Previous scientific attention had mostly been focussed on composition and amounts of phytochemicals in florets rather than leaves and stem. In this research, content of total and individual glucosinolates, total polyphenols and antioxidative capacity were studied in broccoli florets, leaves and stems. Leaves showed to be the most abundant in glucosinolates with indolyl predominating aliphatic as was also the case in florets. In contrast, stem contained more aliphatic than indolyl glucosinolates. Polyphenol quantity ranged from 9.70-16.11 mg GE g-1 DW in stems, from 17.65-31.08 mg GE g-1 DW in florets and from 22.27-34.02 mg GE g-1 DW in leaves and was the highest in leaves irrespective of extraction method. It was determined that samples containing the highest amounts of polyphenols also had the highest antioxidant activity