| Abstract | Salata (Lactuca sativa L.) je jednogodišnja zeljasta povrtna kultura koja pripada porodici glavočika (Asteraceae). Tijekom vegetacijskog razdoblja za njezin kvalitetan rast i razvoj potrebni su svi biogeni makroelementi koje biljka usvaja putem korijena iz otopine tla. Tla u Hrvatskoj općenito su siromašna fosforom pa je gnojidba fosforom od izuzetnog značaja. Cilj ovog rada je utvrditi utjecaj gnojidbe različitim fosfornim gnojivima na status makroelemenata u salati. Poljski gnojidbeni pokus postavljen je u Velikoj Kosnici u Zagrebačkoj županiji na salati po metodi latinskog kvadrata s tri tretmana gnojidbe: T1 (kontrola, bez gnojidbe), T2 (fosfor u obliku polifosfata) i T3 (fosfor u obliku ortofosfata). Dušik je određen prilagođenom Kjeldahlovom metodom, fosfor spektrofotometrijski, kalij plamenfotometrijski, te kalciji i magnezij atomskom apsorpcijskom spektrometrijom. Najveća količina suhe tvari (ST) utvrđena je u T3 tretmanu (8,85 % ST). U tretmanu T1 utvrđena je najveća količina fosfora (0,34 % P), kalija (2,24 % K), kalcija (1,42 % Ca) i magnezija (0,57 % Mg) u suhoj tvari, a u tretmanu T2 utvrđena je najveća količina dušika (2,38 % N) i kalija (2,24 % K) u suhoj tvari. U tretmanu T1 utvrđena je najveća količina fosfora (28,24 mg P/100 g) i magnezija (48,54 mg Mg/100 g) u 100 g svježe tvari salate, a u tretmanu T3 utvrđena je najveća količina dušika (204,34 mg N/100 g), kalija (189,63 mg K/100 g) i kalcija (122,85 mg Ca/100 g) u 100 g svježe tvari salate. |
| Abstract (english) | Lettuce (Lactuca sativa L.) is a annual vegetable part of the family of Asteraceae. During the vegetation period for its quality growth and development lettuce all biogenic macroelements are needeed, that uptake through roots from the soil solution, Soils in Croatia are generally poor in phosphorus, so phosphorus fertilization is of great significance. The aim of this study was to determine the effect of fertilization by different phosphorus fertilizers on the status of macroelements in lettuce. The field fertilization experiment was set up in Velika Kosnica, Zagreb County, with lettuce according to the Latin square method with three fertilization treatments: T1 (control, without fertilization), T2 (phosphorus in polyphosphate form) and T3 (phosphorus in orthophosphate form). Nitrogen was determined by the Modified Kjeldahl method, phosphorus spectrophotometricaly, potassium flamephotometricaly, calcium, and magnesium atomic absorption spectrometricaly. The highest dry weight (DW) content was determined in T3 treatment (8.85 % DW). The highest content in dry weight of phosphorus (0.34 % P), potassium (2.24 % K), calcium (1.42 % Ca) and magnesium (0.57 % Mg) were determined in T1 treatment, while the highest content in dry weight of nitrogen (2.38% N) and potassium (2.24 % K) were determined in T2 treatment. The highest content in 100 g of fresh lettuce of phosphorus (28.24 mg P/100 g) and magnesium (48.54 mg Mg/100 g) were determined in the T1 treatment, while the highest content in 100 g of fresh lettuce of nitrogen (204.34 mg N/100 g), potassium (189.63 mg K/100 g) and calcium (122.85 mg Ca/100 g) were determined in the T3 treatment. |
