Drainage reconstruction in the zone of excessive moisture during the cultivation of blueberries on poorly water-permeable clay soils

Abstract

To ensure efficient agricultural production in the humid regions of Ukraine, drainage of wetlands is one of the first places. The area of drained lands is make up to 9.7% of the total arable lands in Ukraine. In 1990, 1,976.500 hectares were used in active agricultural production, and the share of arable land on drained lands was 70.7%. Of the more than 1130 drainage systems with an area of more than 2.2 million hectares only 37% were built between 1980 and 1990, i.e. younger than 35 years. The remaining 63% of systems have been built and operated for more than 35 years. Since the 1990s, the construction of new and modernization of existing drainage systems in Ukraine has been almost non-existent. Maintenance of the systems was significantly reduced, which led to a significant deterioration in their technical condition, a change in the water regime of soils and the development of degradation processes. Traditionally, in Ukraine, a significant (1.4 million hectares) area is drained with ceramic drainage. We show the experience of reconstruction of the drainage system, which is located in the Pre-Carpathian Upland region of the Ukrainian Carpathians, the Middle Carpathian terrace plain, where a Drainage of Clay Pipes was built more than 35 years ago. The results of the analysis of the reasons of unsatisfactory drainage operation, identification of the most critical zones with the use of field research and earth remote sensing data are presented. To eliminate local wetlands, plastic drainage with a diameter of 50 mm is proposed. To increase the efficiency of its work on heavy clay soils with a filtration coefficient less than 0.01, the backfilling of the trench with local material – gravel with a fraction of 5 ... 25 mm with geotextile protection. During the construction of the new drainage, ceramic drains of the previously constructed drainage were found. They were cleaned mechanically and connected through a filter backfill to the newly built drains.