Y.V. Axenova
Omsk State Agrarian University, Institutskaya pl., 2, Omsk, 644008, Russian Federation
Summary. The influence of long-term (over 30 years) irrigation without drainage on the total content of humus, the composition of the soil-absorbing complex and the medium reaction was studied on meadow-chernozem soils of the Novoomsk irrigation system, allotted for the cultivation of vegetable crops. Watering was carried out from open canals by water from the Irtysh with hydrocarbonate-calcium composition. It was found that in the first 10–15 years the rise of the groundwater level from 5.0–6.0 m to 0.7–3.1 m occurred on the main irrigated area, and its salinity increased from 1.9–4.3 g/l to 5.0–15.0 g/l due to the dissolution of salts contained in the parent rock and the bottom of the soil profile. The total content of humus in reclaimed soils decreased considerably in the layer 0–20 cm from 7.30–7.76 % to 3.79–6.30 %. In the layer 20–40 cm the value of this index was in the range of 3.76–5.58 %. The fraction of calcium in the soil-absorbing complex decreased from 80.7–88.2 % to 75.0–77.9 % with a simultaneous increase in the share of exchange sodium from 0.9–1.2 % to 7.0–9.0 %. The share of magnesium was from 15.7 % to 18.4 % of total exchange cations. The medium reaction was within the range near to the neutral one; pH was 6.6–7.1. The deterioration of the reclamation state of meadow-chernozem soils of the Novoomsk irrigation system is connected with the activation of the dehumification process, resulting in a soil evolution from medium-humic to low-humic. The increased sodium content in the soil-absorbing complex led to the development of solonetz process and the soil transformation into slightly solonetz type.
Keywords: irrigation, humus, exchangeable cations, medium reaction.
Author Details: Y.V. Axenova, Cand.Sc. (Biol.), assoc. prof. (e-mail: Этот адрес электронной почты защищён от спам-ботов. У вас должен быть включен JavaScript для просмотра.).
For citation: Axenova Y.V. Dynamics of Properties of Meadow-Chernozem Soils under Conditions of Prolonged Irrigation. Dostizheniya nauki i tekhniki APK. 2016. V.30. No 5. Pp. 30-32 (In Russ.).