Features of protein accumulation in green mass of Sudan grass

Abstract

Due to climate change, in order to increase crop areas and expand the potential for using crops as feed for various animals, the study of the main nutritional indicator – protein content – is of great relevance. The purpose of the current study was to analyze the accumulation of crude protein in the dry matter of green mass of Sudan grass. The study was conducted in 2023-2025. The soil was ordinary carbonate blackearth with 3.2% of humus, 10–40 mg of phosphorus, 70–110 mg of nitrogen, and 300–500 mg of potassium per kg. The hydrothermal coefficient ranged from 0.24 (in 2024) to 0.81 (in 2023), indicating the contrasting conditions of the study. The objects of the study were the Sudan grass varieties Alisa, Gratsiya, and Selchanka, developed by the FSBSI “ARC “Donskoy”. The trials were conducted in accordance with the Methodology of the State Commission for Variety Testing of Agricultural Crops. The studied varieties had similar crude protein percentage, with the variety Selchanka slightly exceeding it at all stages of the vegetation period. There has been recorded the highest crude protein percentage during the tillering stage (18.8–19.7%). By the heading phase, this value has dropped almost twofold (10.0–11.1%) and continued to decline up to the end of the vegetation period. This was due to a decrease in the proportion of leaves in the total green mass yield from 36% (a booting stage) to 18% at a dead-ripe stage. Crude protein accumulation in leaves amounted to 12.8–15.4%, which was 40–85% higher than in the stem and 18–39% higher than in the whole plant. On average, among the varieties, the regression of crude protein content in the second cutting was 17.1% compared to the first cutting, green mass productivity was 26.3%, dry matter productivity was 34.1%, digestible protein yield was 37.5%, and feed unit yield was 1.1%.