TECHNIQUES FOR IMPROVING OLD-AGED DISUSED LANDS IN THE WEST SIBERIAN FOREST STEPPE

Abstract

Results are given from studies on improving old-aged disused lands in the West Siberian forest steppe, which were conducted in 2011–2014. The SibNIISKhoz 189 variety of smooth bromegrass (Bromopsis inermis (Leyss) Holub.) and Sibirskaya 8 variety of bastard alfalfa (Medicago varia Mart.) were sown. The variants of experiment were as follows: control (old-aged disused land); amelioration + drill sowing of smooth bromegrass and alfalfa; amelioration + skip-row sowing of smooth bromegrass and alfalfa; direct drilling of smooth bromegrass and alfalfa; rotary tillage without overdrilling; rotary tillage + drill sowing of smooth bromegrass and alfalfa; rotary tillage + skip-row sowing of smooth bromegrass and alfalfa. Most of leguminous plants (18.8%) were observed in the variant of ameliorating old-aged disused land + skip-row planting of smooth bromegrass and alfalfa. The proportion of motley grasses in the botanical composition of herbage on old-aged disused land decreased from 27.1 to 11.3–21.1% at different methods for sod plowing and direct drilling of perennial grasses. The variant with amelioration + skip-row sowing of smooth bromegrass and alfalfa turned out to be most productive: the yield of green mass was 5.96 t/ha, that of dry mass 1.75 t/ha. The variant with direct drilling of smooth bromegrass and alfalfa was somewhat inferior to it in productivity: the yields of green and dry mass were 4.46 and 1.29 t/ha, respectively. The amount of digestible protein per fodder unit was 119 g. The control variant of field experiment (old-aged disused land) showed productivity by 1.2–2.9 times lower as compared with the improvement techniques. Direct drilling of smooth bromegrass and alfalfa was found to be the most energy-favorable variant among techniques for ameliorating old-aged disused lands. Rotary tillage of sod without overdrilling of perennial grasses was least energy-favorable.