Author(s)

F. I. Mathivha, P. M. Kundu, J. O. Odiyo & R. Makungo

Abstract

Utilization and management of irrigation water is essential for sustainable farming. The Macadamia cropland in Piesanghoek cropland falls in the arid to semi-arid climatic zone in Limpopo Province of South Africa. It is estimated that irrigated agriculture accounts for 62% of all the water used in South Africa and in many instances, its use is highly inefficient. A few farmers have adopted new computerized technologies for irrigation management but many still use conventional irrigation methods, which are not based on crop water requirements, leading to poor water utilization and low irrigation efficiencies. This study evaluated the Piesanghoek Macadamia cropland to determine the irrigation scheduling schemes for efficient utilization and management of water. Soil samples were analysed for particle size distribution and bulk density while field tests were carried out to determine infiltration rates on the cropland, after which geostatistical tools in ArcGIS were used to show the spatial variability. The South Africa Plant Water (SAPWAT) model was used to automate the irrigation scheduling. The results showed that the supply and availability of soil moisture was of fundamental importance to plant growth and crop production. It also showed that changes in the soil moisture stored in the root-zone were due to differences between the inputs and outputs from this zone. An irrigation efficiency of 80% was achieved and it was observed that the Macadamia trees did not use as much water as the SAPWAT model prescribed. Keywords: crop water requirement, efficient utilisation, geostatistical tools, Macadamia, SAPWAT.

Keywords

crop water requirement, efficient utilisation, geostatistical tools,Macadamia, SAPWAT.