THE ENERGY EFFICIENCY OF SPRING WHEAT DEPENDING ON THE BACKGROUND OF MINERAL NUTRITION AND PREDECESSOR IN CONDITIONS OF FOREST-STEPPE OF THE URAL
The article reflects the results of a study of seed production, energy efficiency of cultivation of new varieties of spring soft named Ecatherina, included into State register of breeding achievements with 2015 on the Volga-Vyatka and West-Siberian regions of the Russian Federation, in comparison with Iren and Gornouralskаyа. A reaction is studied on the background of mineral nutrition (unfertilized and N P K) and predecessor (winter rye and clover) in a stationary grain-fallow-grass crop rotation, the past five rotations with the following alternation of crops: bare fallow, winter rye, spring wheat and undersown clover, clover the I year of use, clover II year of use, pea-oat mixture on herbage, barley, oats during favourable 2014 and less favorable 2013. Maximum value from mineral fertilizers was observed in variety Ecatherina - 1.39 t/ha, or 70.9% (winter rye), and 1.06 t/ha, or 36.8% (clover). Other varieties are amounted to 0.99-1.06 t/ha and 0.74-0.82 t/ha respectively. Increase from its predecessor clover is higher than winter rye and equal to depending on grade of the background on 0.60-0.96 t/ha, with fertilizer dose N <sub>60</sub>P <sub>60</sub>K <sub>60</sub> on 0.42-0.64t/ha. Clover has improved the energy efficiency of spring wheat, compared to the predecessor of winter rye was an increase in net energy revenue for all sorts in the background without fertilizer of 6.3 to 13.5 GJ/ha and on the background N <sub>60</sub>P <sub>60</sub>K <sub>6Q</sub> - 3.5-6.7 GJ/ha, a decline in the energy intensity on 1.7-3.8 GJ/ha and on 0.7-1.2 GJ/ha, the increase of energy efficiency ratio on 14.9-40.0% (unfertilized background) and on 3.2-9.8% <sup>(N</sup>60 <sup>P</sup>60 <sup>K</sup>60 <sup>)</sup>. M <sup>id-earl</sup>y v <sup>arie</sup>ty Ekaterina generated the highest yield of all the predecessors and the backgrounds of mineral nutr <sup>60</sup>iti <sup>6</sup>o <sup>0</sup>n <sup>6</sup>i <sup>0</sup>n excess of Iren and Gornouralskаyа by all indicators of energy efficiency in the cultivation in the conditions of forest-steppe of the Ural.