| Sažetak | Salata (Lactuca sativa L.) je jednogodišnja biljka iz porodice Asteraceae koja se uzgaja kao lisnato povrće. Uzgaja se diljem svijeta uglavnom na tlu. Za razvoj su salati kroz vegetaciju potrebni esencijalni makro- i mikroelementi koje većinom usvaja kroz korjenov sustav. Mikroelementi su zastupljeni u salati u manjim količinama od makroelemenata, ali su ključni za njezin razvoj jer doprinose brojnim fiziološkim procesima. Mnogo čimbenika utječe na količinu mikroelemenata, a jedan od najznačajnijih je gnojidba. Cilj ovog istraživanja bio je utvrditi utjecaj gnojidbe različitim oblicima fosfora na količinu mikroelemenata u salati. Gnojidbeni pokus je proveden u Velikoj Kosnici u Zagrebačkoj županiji na salati sorte 'Aquarel', a postavljen je po metodi latinskog kvadrata s tri tretmana gnojidbe: T1 (kontrola, bez gnojidbe), T2 (500 kg/ha YaraMila Complex; fosfor u obliku polifosfata) i T3 (370 kg/ha Petrokemija NPK 15-15-15; fosfor u obliku ortofosfata). Prosječni uzorci listova salate usitnjeni su i osušeni na temperaturi od 105°C, te homogenizirani. Uzorci su razgrađeni dušičnom (HNO3) i perklornom kiselinom (HClO4) u mikrovalnoj peći. Željezo, cink, mangan i bakar određeni su atomskom apsorpcijskom spektormetrijom AAS. Suha tvar određena je gravimetrijski sušenjem do konstantne mase. Najveća količina suhe tvari (ST) je utvrđena je u T3 tretmanu (8,85 %). Količina mikroelemenata u suhoj tvari lista salate (mg/kg suhe tvari) iznosila je Fe 1280-2373, Zn 36,0-48,5, Mn 54,1-87,6 i Cu 9,4-10,7, dok je u svježoj tvari (mg/100 g svježe tvari) iznosila Fe 10,5-20,6, Zn 0,30-0,41, Mn 0,45-0,76 i Cu 0,078-0,091. Najviše vrijednosti mikroelemenata utvrđene su u tretmanu bez gnojidbe (T1) jer je kalij, primijenjen u gnojidbenim tretmanima, vjerojatno djelovao antagonistički na njihovo usvajanje. |
| Sažetak (engleski) | Lettuce (Lactuca sativa L.) is an annual plant of the Asteraceae family, which is grown as a leafy vegetable. Worldwide lettuce is mostly produced on soil. For its development during vegetation, lettuce requires essential macro- and microelements, which uptake by root system. Microelements are present in lettuce in lower content than macroelements, but are essential for its development, as they contribute many physiological processes in the plant. There are many factors which effect content of microelements and one of the most important ones is fertilization. The goal of this research was to determine the effect of fertilization by different phosphorus forms on microelements content in lettuce. The field fertilization experiment was set up in Velika Kosnica (Zagreb County, Croatia) with lettuce cultivar 'Aquarel' according to the Latin square method with three fertilization treatments: T1 (control, without fertilization), T2 (500 kg/ha YaraMila Complex; phosphorus in polyphosphate form) and T3 (370 kg/ha Petrokemija NPK 15-15-15; phosphorus in orthophosphate form). Average lettuce leaves samples were cut up, dried at 105°C and homogenized. The samples were digested by nitric acid (HNO3) and perchloric acid (HClO4) in microwave owen. Iron, zinc, manganese and copper were determined by atomic absorption spectrometry-AAS. Dry matter was determined gravimetrically by drying until constant mass. The highest dry weight (DW) content was determined in T3 treatment (8.85 % DW). Microelements content in dry matter of lettuce leaves (mg/kg dry matter) ranged: Fe 1280-2373, Zn 36.0-48.5, Mn 54.1-87.6 and Cu 9.4-10.7, while in fresh matter (mg/100 g fresh matter) it ranged: Fe 10.5-20.6, Zn 0.30-0.41, Mn 0.45-0.76 and Cu 0.078-0.091. The highest values of microelements were determined in the treatment without fertilization (T1) because potassium, applied in fertilization treatments, probably had an antagonistic effect on their uptake. |
