The effect of nitrogen fertilizers on the changes of photosynthetic pigments in winter wheat

Abstract

The paper deals with the effect of nitrogen fertilizers on photosynthetic pigments in winter wheat. The investigation was carried out at the Experimental Station of Aleksandras Stulginskis University during the period of 2009–2010. The soil: carbonate shallow gleyic leached (Idg8-k), Calc(ar)i-Epihypogleyic Luvisols (LVg-n-w-cc). The objects of investigation: wheat cultivars ‘Ada’ and ‘Tauras DS’. During the sowing time complex fertilizer (N32P80K120) was used, and calcium ammonium nitrate (N60) was used at the stage of spring tillering. In addition, foliar fertilizer urea solution (N30, N40) was given during the booting stage and (N15, N30) was given at the milk ripening stage. It was established that nitrogen fertilizers stimulated an overall increase in pigment content in plants before flowering. Additional fertilization with nitrogen (N30 and N40) during the late stages of plant development encouraged the accumulation of pigments and prolonged the period of active photosynthesis. The ‘Ada’ plants fertilized with a rate of N30 had an overall content of pigments of 4.60 mg g-1, and those fertilized with N40 accumulated 4.45 mg g-1, whereas in the ‘Tauras DS’ plants fertilized with N40 the overall content of pigments was 3.71 mg g-1. After flowering, when the ageing process started, the total pigment content began to decrease