Effects of different mulch types on soil moisture content in potted shrubs

Abstract

South Africa is classified as a semi-arid environment with limited natural water resources and variable rainfall. It is also described as water scarce, with many of its water resources already fully exploited. Gardening is one of the principal methods that people use to experience nature, and gardens can also be a public demonstration of personal value, a source of satisfaction, and part of a connection to the community. However, gardens are also one of the top users of water, accounting for approximately 31–50% of potable water supplied for domestic and urban use. In order to reduce the amount of water used in gardens, water conservation strategies such as mulching need to be employed. In view of South Africa’s water situation, it is Rand Water’s aim to promote the wise use of water, in all aspects of water consumption. It is anticipated that this study will provide information useful to water saving in urban gardens and landscapes, and will promote the use of mulch amongst gardeners, landscapers and the general public. Mulching potted plants with various organic and inorganic mulch was found to conserve an average of 35% more soil water content over approximately 6 weeks of no irrigation than plants with no mulch. Mulch was shown to increase plant health and vitality, as indicated by stomatal conductance, by an average of 44% than plants with no mulch. The recommended mulch type for use in gardens is bark chips in both summer and winter seasons.