Influence of hydrothermal conditions on the productivity of perennial grasses in South Steppe of Ukraine

Abstract

The purpose is to determine the productivity of perennial legume and cereal grasses under conditions of natural moisture supply in South Steppe of Ukraine. Method. The studies were conducted during 2016—2018 using conventional methods, and the output of feed units, digestible protein per unit of area was determined by reference books. Results. On average over three years of research, the highest yield of leaf-stem mass of cereals was formed by Bromus inermis and Elytrigia medium tender – 11.6 and 11.2 t/ha, respectively. The lowest yield was formed by Agropyrum pectiniforme – 7.6 t/ha. Among the all legume grasses, Melilotus albus prevailed (14.8 t/ha). Medicago sativa and Onobrychis arenaria were able to form a similar yield (14.5 and 13.5 t/ha, respectively) under the arid conditions of South Steppe of Ukraine. Insufficient rainfall in 2017 caused a decrease in the productivity of the studied crops. Thus, in 2017 the average yield of green mass in the experiment was 10.3 t/ha, while in 2016 under more favorable weather conditions this figure was 13.2 t/ha or 28.2 % more. The highest output of feed and protein units (FPU) per unit of area under cereal grasses was provided by Bromus inermis (2.35 t/ha). The lowest one was recorded in Agropyrum pectiniforme (1.60 t/ha). FPU output per unit of area under legume grasses increased respectively. Lotus corniculatus provides less green mass and therefore dry matter and forage and protein units. Perennial cereals grasses do not prevail over legume grasses, so they do not spread in South Ukraine. Conclusions. The productivity of perennial grasses in the south of Ukraine significantly depends on the type of plants, weather (hydrothermal) conditions of the year. The most effective is the cultivation of perennial legumes, namely Melilotus albus, alfalfa, Onobrychis arenaria. Bromus inermis and Elytrigia medium prevail among cereal grasses.