Peculiarities of the biomass yield and quality formation in giant miscanthus under the effect of agricultural technology components

Purpose. To establish the peculiarities of the dry biomass productivity and quality formation in giant miscanthus under the effect of agricultural technology components. 
Methods. The research was carried out at the Bila Tserkva Experimental and Breeding Station of the Institute of Bioenergy Crops and Sugar Beet National Academy of Agrarian Sciences in the years 2019–2021. In the research, generally accepted methods were used. Giant miscanthus variety ‘Osinnii Zoretsvit’ was grown in a three-factor field experiment with the use of the following formulations: Azophosphoryn for inoculation (1,0 l/ha), adsorbent MaxiMarin granulated (30 kg/ha), Humate potassium (Humifield) (50 g/ha) and Antistress AminoStar (1,0 l/ha) for foliar fertilization over vegetation. 
Results. The productivity of miscanthus in the second year of vegetation (2020) was quite low since the development of plants was aimed primarily at forming a powerful root system, particularly rhizomes. On average in the experiment, the leaf and stem biomass weight of one plant ranged from 177.0 to 240.0 g, and the yield of solid biofuel from 5.84 to 7.92 t/ha. The maximum values of these indicators were observed in the treatments with the combined use of Azophosphoryn and MaxiMarin (236–240 g/plant. and 7.79–7.92 t/ha, respectively). At the same time, the foliar application of fertilizers in the first year of the experiment was ineffective: the differences in plant productivity indicators were rather tendentious. In the third year of miscanthus cultivation (2021), all treatments demonstrated a significant – approximately threefold – increase in the productive indicators. In particular, the weight of one plant was 531.8–772.2 g, solid biofuel yield 17.5–23.8 t/ha, and energy yield 287.8–391.1 GJ/ha. As in the previous year of research, their maximum values were obtained in the treatments with the combination of inoculant and adsorbent; foliar fertilization also proved to be an effective practice. As for the qualitative characteristics of the obtained crop biomass, on average in the experiment, the content of dry matter was 48.8%, cellulose 40.0%, lignin 10.3%, and ash 1.3%. The variation of these indicators under the effect of the studied factors was mostly insignificant (within the limits of error). 
Conclusions. In the third year of giant miscanthus variety ‘Osinnii Zoretsvit’ cultivation, the highest yield of solid biofuel (23.8 t/ha) and energy yield (391.1 GJ/ha) was provided by the combined use of inoculant Azophosphoryn, adsorbent MaxiMarin granulated and foliar application of fertilizer Potassium humate (Humifield) + Antistress AminoStar.