Peculiarities of the productivity formation and biomass quality of switchgrass on acid soils

Abstract

Purpose. To reveal the peculiarities of the productivity and quality of the biomass of switchgrass in the third year of vegetation when grown on acidic soils belonging to the category of marginal. Methods. The research was conducted during 2019–2021 at the Uladovo-Liulyntsi Experimental Breeding station of the Institute of Bioenergy Crops and Sugar Beet of the NAAS of Ukraine according to generally accepted methods. Variety ‘Morozko’ was grown according to the scheme of a three-factor field experiment, with the use of soil liming, MaxiMarin granulated adsorbent (30 kg/ha) , as well as potassium humate (Humifield) (50 g/ha) and antistress product AminoStar (1.0 l/ha). The adsorbent was applied two weeks before sowing the crop locally in the rows, and foliar application of fertilizers was carried out in the budding stage and again two weeks later. Results. On average, according to the experiment, the productivity of switchgrass in the third year of vegetation was 60% higher compared to the second year – 5.70 versus 3.56 t/ha. At the same time, in the control treatments of the experiment, the crop plants formed an average of 5.3–5.5 t/ha of dry matter. The maximum indicators of the crop productivity in the third year of growing were obtained in the treatments with adsorbent MaxiMarin granulated and foliar application of Potassium humate (Humifield) + antistress product AminoStar: the yield of dry mass was 6.1 t/ha, and the energy yield was 102.4 –102.5 GJ/ha. On average of the experiment, switchgrass plants in the third year of vegetation formed the fiber content in leaves and stems at the level of 54.2%. The fiber content in leaves and stems depended on the application of agrotechnical measures. In particular, their highest indicators were obtained when using MaxiMarin granulated adsorbent and foliar application of potassium humate (Humifield) + AminoStar − 55.3 and 55.6%, respectively. As for the ash content, on average in the experiment, it was 7.63% in the leaves and 2.22% in the stems. In the treatments where lime was added to the soil (25% of the requirement), these indicators were 7.25 and 2.05%, respectively. Conclusions. The highest indicators of dry biomass yield and energy yield in the third year of switchgrass vegetation are ensured by the use of such agrotechnical measures as the application of MaxiMarin granulated moisture retainer in combination with subsequent foliar application of humates in combination with the antistress product AminoStar. The measures to deoxidize the soil did not have a significant impact on the formation of crop productivity.