I.G. Eremina, N.V. Kutkina
Research Institute of Agrarian Problems of Khakassia, ul. Sadovaya, 5, s. Zelenoe, Ust’-Abakanskii r-n, Respublika Khakasiya, 5655132, Russian Federation
Abstract. The studies were carried out in 2013–2014 in the closed basin of the lake and steppe area of Shira district of the Republic of Khakassia. The aim was to study the influence of the slopes of different expositions and their parts on the formation of agrocenosis productivity during the development of postagrogenic chernozem. The slope landscapes differed in the heterogeneity of the soil fertility; an increase in the thickness of the humus-accumulated horizon on average by 18 cm and the largest humus content (4.0 %) was noted at the toe of the slopes, which also positively affected the accumulation of total humus supplies in the half-meter layer to a middle level (225 t/ha). The soils on the increased relief elements yielded to the soils in the topographic low in the nitrogen reserves and in the accumulation of phosphorus and potassium mobile forms on average from 5.0 % to 27.7 %. The advantage of a leveled cultivated land was determined by the largest harvest of grain (2.1–2.2 t/ ha) with yield variability over the field of 4.5 %. Close values of productivity were obtained at the toes of the slopes: 2.2 t/ha (the eastern and southern exposition). The decrease in the total productivity on the slope of the western exposition (1.4 t/ha) was due to the different level of accumulation of soluble salts in the soil profile, and on the eastern slope (1.8 t/ha) – due to the erosional feature and the content of crushed stone. The soil cover of the slopes of the northern and southern expositions is more homogeneous, that is why the grain harvest reached 2.1 t/ha and 1.9 t/ha, respectively. The spatial variability of the productivity in the closed basin more depended on the steepness, erosional feature, and deflation than on the exposition factor. It appeared mostly in the case of the rotation of elementary landscapes within one exposition (up to 43 %, the western and eastern expositions). In general, the best conditions for the cultivation of grain crops in the closed basin were on the mild slopes (1–2 degrees), on the carbonated chernozem developed on yellow-brown rocks. It is necessary to exclude the upper eroded and saline slope sections from the arable use because of their low productivity and their unsuitability for arable soil standards.
Keywords: productivity, agrocenosis, slope relief, slope exposition, part of the slope, variation coefficient, chernozem, thickness of humus horizon, humus reserve.
Author Details: I.G. Eremina, Cand. Sc. (Biol.), research fellow (e-mail: Этот адрес электронной почты защищён от спам-ботов. У вас должен быть включен JavaScript для просмотра.); N.V. Kutkina, Cand. Sc. (Biol.), head of group.
For citation: Eremina I.G., Kutkina N.V. Productivity of Agrocenosis of Cultivated Chernozem in the Republic of Khakassia. Dostizheniya nauki i tekhniki APK. 2017. Vol. 31. No. 7. Pp. 55-58 (in Russ.).