Effect of mineral fertilizers on Sudan grass herbage yield in the north-west of the Central Chernozem Region

Abstract

Sudan grass is a high-yielding forage crop. It fits successfully into the traditional forage production schemes of the north-west of the Central Chernozem Region (Lipetsk Region) due to its beneficial properties and methods of use. The research goal was to study the effect of various rates of complete mineral fertilizer on herbage yield of Sudan grass in order to substantiate the growing techniques of this crop on leached chernozems in this region. The research target was the Kinelskaya 100 variety of Sudan grass. It was found that the use of mineral fertilizers for Sudan grass even against minimal background of N₃₀P₃₀K₃₀ increased the yield by 9.45 t ha of herbage at ear emergence stage. At higher levels of mineral nutrition with N₆₀P₆₀K₆₀ and N₉₀P₉₀K₉₀, the yield gain compared to the non-fertilized variant made 73.4-82.8%. The yield of plant raw materials of Sudan grass was formed by the stems and leaves of the entire plant. The plant indices - linear height, length and width of leaves, the number of leaves per plant, and stem diameter - were directly dependent on the fertilizer rates. The higher the fertilizer background was, the higher these indices were. Against the background of N₉₀P₉₀K₉₀, the plant height at the grain maturation stage was 180 cm and was by 25 cm higher compared to the non-fertilized variant; the foliage was by 4.4% larger, and the stem diameter was larger by 0.5 mm. The correlation coefficient (r = 0.67 + 0.05) indicates that the taller the plant is, the more herbage is formed. In the Lipetsk Region, the largest amount of forage herbage of Sudan grass of the Kinelskaya 100 variety which grows intensively after the first mowing falls on two-cuts harvesting system. The productivity of the second mowing makes 73-79% of the first mowing.