Effect of fertilizers on yield, bioethanol yield, and energy productivity of sorghum (bicolor)

Abstract

Goal. To determine the impact of doses of nitrogen fertilizers and foliar feeding with silicon on yield, bioethanol yield, and energy productivity of sorghum (bicolor). Methods. Field (determination of the impact of nitrogen fertilizer doses on the yield of sorghum (bicolor)), analytical (determination of starch content in grain), calculation (determination of energy productivity), mathematical and statistical (study of research results using the Statistica 2013 program). Results. The study was conducted in a temporary field study in 2021–2025 at the Uladove-Lyulinetsk experimental selection station of the Institute of Bioenergy Crops and Sugar Beets of NAAS. The soil of the field was podzolised chornozem. The results of field studies on the effectiveness of the use of nitrogen fertilizers and silicon to increase yield, bioethanol yield, and energy productivity of sorghum (bicolor) are presented. It was determined that in conditions of sufficient moistening, sorghum (bicolor) reacted positively to the introduction of high doses of nitrogen fertilizers and foliar feeding with silicon, and formed high yields, as a result of which bioethanol yield and grain energy productivity increased. Conclusions. For the cultivation of sorghum (bicolor) in conditions of sufficient moistening, the highest biological productivity on the leached chornozem was achieved by the introduction of straw (5 t/ha) + N120P60K60 + Si (1.0 l/ha), the grain yield was 8.8 t/ha, the starch content in the grain was 67.1%, which exceeded the control without fertilizers by 3.0 t/ha and 4.3%, respectively. The use of straw (5 t/ha) + N120P60K60 + Si (1.0 l/ha) provided the highest bioethanol yield — 2.57 t/ha, and the highest energy productivity — 64 GJ/ha, which, respectively, was more than the control by 0.99 t/ha and 25 GJ/ha. During the application of nitrogen fertilizers, the yield of bioethanol increased by 0.38–0.67 t/ha, and the energy productivity of grain by 10-17 GJ/ha, and for feeding with silicon, by 0.08-0.20 t/ha and 2-5 GJ/ha, respectively.