A. ILIEVA. I. PACHEV and T. KERTIKOV
Institute of Forage Crops, BG - 5800 Pleven, Bulgaria
ILIEVA, A,. I. PACHEV and T. KERTIKOV, 2007. Influence of different soil cultivation and fertilizing on the content of plastid pigments and nitrate reductase activity in lucerne for forage. Bulg. J. Agric. Sci., 13: 45-50
In a field trial carried out in the Second experimental field of the Institute of Forage Crops in Pleven the influence of mineral fertilizing (N6P10K8, N2.3P10K3.5, N3.5P8K5.0 and Amophos) and different soil cultivations (12-15 cm loosening and ploughing at 12-15 cm, 22-24 cm, 18-22 cm, 30-35 cm) on the nitrate reductase activity (NR) and content of plastid pigments was studied. It was found that the NR activity in leaves exceeded 4 to 8 times the activity in stems and roots of lucerne. The different rates of mineral fertilizing and soil cultivation exerted a different influence on the NR activity and total content of plastid pigments. The application of N6P10K8 by approved technology increased the NR activity and total content of plastid pigments to the greatest degree under ploughing at 22-24 cm.
The maximum value of NR activity (15.08 µmol NO2-/g fr.w./h and high content of plastid pigments (313.6 mg/100 g fresh mass) were observed for Amophos application under 18-22 cm ploughing. A medium positive correlation was found between NR activity and content of plastid pigments (r=0.40).
The two-factor variance analysis of the results showed the strong influence of mineral fertilizing - 54.6 % on the NR activity and the slighter influence
of the soil cultivation on the content of plastid pigments.