A. Stoyanova1*, G. Ganchev2, V. Kuneva3

1Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Morphology, Physiology and Animal nutrition, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria 3Department of Mathematics and Informatics, Faculty of Economics, Agricultural University, 4000 Plovdiv, Bulgaria

(Manuscript received 29 June 2018; accepted for publication 3 September 2018)

Abstract. . Two years of polls from the field trials of the Faculty of Agriculture, Trakia University, Stara Zagora, Bulgaria were used for the purpose of the survey. In the period 2015-2016, two varieties of common wheat (Apolon and Bolonga), treated by leaf liquid fertilizers, imported alone and in combinations were tested under field conditions. Main fertilization with ammonium nitrate was done. The variants of the experiments were as follows: 1) Without fertilization (Control); 2) Ammonium nitrate (N140); 3) Lactifrost – l0.0 L/ha; 4) Lactifros + Lactofol base – 10.0 L/ha + 5.0 L/ha; 5) Lactofol base – 5.0 L/ha; 6) Wuxal Grano – 4.0 L/ha; 7) Wuxal Grano – 4.0 L/ha + 2.0 L/ha. It was found that crude protein content ranged from 136.90 to 144.63g/kg DM in the Apolon variety and from 129.98 to 145.12 g/kg DM in the Bologna variety. An increase in CP content was seen as a result of feeding with Lactifrost and Lactofol base, respectively, by 5.6% and 11.7% relative to the control. Treatment of common wheat with liquid leaf fertilizers, however, does not lead to improvements in energy (metabolizable energy, digestible energy, feed unit for milk, feed unit for growth) and protein digestible in (small) intestine nutrition. In both varieties there were many positive and negative correlations between the investigated parameters: CP, CFAT, CF, DEE, FUM, FUG, PDI, Dep, MEp, DEpg and MEpg; in ruminants the same positive correlations for both varieties are between CP and PDI (p<0.01) and negative – between CP and FUM (p<0.05), and between CFAT and PDI (p<0.05); in nonruminants negative correlations exist between CF and the energy values (DEp, MEp, DEpg and MEpg) only in Apolon variety.