YIELD FORMATION IN RHAPONTICUM CARTHAMOIDES AND FODDER QUALITY AS INFLUENCED BY MINERAL FERTILIZERS

Abstract

Results are given from research into impacts of different combinations of mineral fertilizers on yield formation in Rhaponticum carthamoides from the herbages of 1 to 6 years of utilization. Variants of an experiment were: no fertilizers (control); P 60 K 60 ; N 60 K 60 ; N 60 P 60 ; N 60 P 60 K 60 . For the years (2011–2016) of study, excellent wintering of the plants was observed. It has been established, when determining the photosynthetic activity in the herbages of 3 to 5 years of utilization, that the plants very quickly (within 10–20 days) form the maximum leaf surface and actively increase the green mass yield. The maximum leaf surface of 181.0 ths square meters per ha is formed at the beginning of flowering. All combinations of nutrition elements applied have provided an increase in the yields of green and dry mass as compared with the treatment without fertilizers. It is especially noticeable when nitrogenous fertilizers are applied. On average for 6 years, the maximum yields of green mass (45.8 tonnes per ha) and dry mass (7.72 tonnes per ha) were obtained in the N 60 P 60 treatment. The minimum yields of green and dry mass (25.2 and 4.51 tonnes per ha, respectively) were obtained in the control (no fertilizers). Rhaponticum grown under conditions of Perm Territory is characterized by high feeding qualities. The contents of dry matter and crude fiber were within the limits of zootechnic optimum for high-producing cows. The concentration of metabolizable energy across all the treatments varied from 11.39 to 12.27 MJ/kg, crude protein content in dry matter was 13.69–15.24%. Energy inputs for cultivating Rhaponticum are quickly paid back by the products obtained. The energy efficiency coefficient across the treatments ranged from 6.0 to 9.9. The maximum profitability of 323% was in the N 60 K 60 treatment.