Vladia Subkova 1* ,  Evlogy Markov 2  1 Institute for Land Reclamation and Mechanization, Sofia, Bulgaria  2 “N. Pushkarov” Institute of Soil Science, Sofia, Bulgaria vlpsubkova@mail.bg   Abstract Essential for obtaining high yields of fruits depends on the proper quantity of nitrogen fertilizers, as well as timing and manner of its submission. The effect is […]