Low-cost soil conservation technique for controlling gully erosion in the semi-arid area of the Free State province

Abstract

In South Africa, soil erosion is a major problem confronting natural resources. Gully erosion has a huge negative impact on soil productivity and potable water supplies, while measures to control it are expensive. Sannaspos farm which has been threatened by gully erosion was selected as a demonstration site for controlling gully erosion using low-cost control measures. The main aim of this study was to control gully erosion resulting in improved rangeland production. The technique entailed the use of old tyres and bags filled with soil. Three reference points were selected along a 240 m gully in August 2016 and monitored over 42 months. After 17 months (January 2018), gully depth decreased from 70 to 34 cm, 45 to 20 cm and 35 to 19 cm at the three reference points. After 24 months (August 2018) gully depth further decreased from 34 to 27 cm, 20 to 14 cm, and 19 to 10 cm for the three points. Thirty months after installing control measures (February 2019), the gully was sealed at all reference points. By February 2020 (42 months after initiation of the trial), the entire gully was sealed and covered with various vegetation types. Use of this low-cost method to control gully erosion is recommended under similar conditions.