Irrigation
IRRIGATION
Ideally, water should be readily available to all plants and in sufficient quantity if maximum growth is to be achieved. In southern Africa, irregular rainfall is a major limiting factor for plant growth, and irrigation, therefore, plays a very important role. The increased revenue from crop yield response to irrigation must cover the irrigation capital and operating costs.
Information and advice related to irrigation can be found in the various publications, videos and smartphone apps described below.

Dr Ashiel Jumman

Details
Agricultural Engineer
Tel: 031 508 7400 (Switchboard)
Tel: 031 508 7431 (Direct)
Email: ashiel.jumman@sugar.org.za
Role & Overall Purpose
- Identify knowledge gaps and research needs.
- Initiate, manage and conduct research and development projects and provide expert advice and technical support to unique water related problems in the context of sugarcane production.
Expertise
- Assessment of irrigation systems design & management alternatives with respect to costs and crop yield response.
- Irrigation system monitoring and evaluation.
- Irrigation scheduling and soil water monitoring.
Research Interests
- Sugarcane agriculture and optimal utilisation of water resources.
- Water use strategies in the context of climate change and climate variability.
- Energy use for sugarcane production.
- Sustainable farming practices.
Key Publications
Armitage, R, Lecler, NL, Jumman, A and Dowe, K. 2008. Implementation of the Irriecon V2 decision support tool to assess net returns to irrigation systems. Proc S Afr Sug Technol Ass (2008)45.
Jumman, A and Lecler, NL. 2008. A continuous water potential measurement system for irrigation scheduling assessment. SANCID 2008 symposium. Langebaan. Western Cape. RSA.
Jumman, A and Lecler, NL. 2009. A tool for the analysis of irrigation design alternatives. SABI Congress. Vanderbijlpark. Gauteng. RSA.
Lecler, NL and Jumman A. Irrigated sugarcane crop production functions. Proc S Afr Sug Technol Ass (2009)604.
Jumman, A and Lecler, NL. 2009. Short comm.: A continuous water potential measurement system for irrigation scheduling assessment. Proc S Afr Sug Technol Ass (2008)608.
Jumman A and Lecler N.L. 2010. Deficit Irrigation: A potential strategy to counteract the escalating electricity tariffs and water shortages. Proc S Afr Sug Technol Ass (2010)160.
Jumman A and Lecler N.L. 2010. Poster. Electricity tariff increases: The impact on irrigators? Proc S Afr Sug Technol Ass (2010)152.
Qualifications
MSc Eng (Agriculture), PhD (UKZN)
Information Sheets
- 5.1 Irrigation fundamentals
- 5.2 Irrigation strategies for water limiting periods
- 5.3 Basics of irrigation scheduling
- 5.4 Irrigation scheduling toolbox
- 5.5 Chemigation: principles and fundamental equipment
- 5.6 Chemigation: guidelines for choosing chemicals
- 5.7 Introduction to irrigation systems
- 5.8 Irrigation systems selection
- 5.10 Energy inputs and electricity saving
- 5.11 Properties of saline/sodic soils and their reclamation
- 5.12 Irrigation water quality for sustaining soil health and sugarcane yield
- 5.13 Water quality considerations for optimal performance of irrigation equipment
- 5.14 Irrigation system maintenance
- 5.15 Irrigation costs estimates
- 5.16 Assessing economic viability of irrigation
- 5.17 Placement of soil water sensors for irrigation scheduling
- 5.18 Evapotranspiration (ET) Calendars
Videos
Irrigation (isiZulu)
Smartphone & Desktop Applications
Irrigation Scheduling Calendar DSP (ISCDSP)
The ISCDSP is a spreadsheet-based tool which generates optimal guidelines for the timing of irrigation for specified inputs such as irrigation amount (mm), geographic location, row spacing (single vs tramline) and ground cover (burnt vs mulched). Based on a database of model-generated sugarcane ET from LTM weather data for a number of sites, the DSP calculates the time to deplete applied irrigation under zero rainfall circumstances and suggests dates for the first two irrigation events and the subsequent ‘no rain’ cycle length for each month in the remaining season. The generated calendar is based on robust long-term mean data and must be accompanied by a rain delay calculator to adjust irrigation cycle lengths for rainfall on a real-time basis.
Rain Delay Calculator
The rain delay calculator is a laminated cardboard dial. The dial allows a user to look at the number of days that irrigation should be delayed for after rain, based on the amount of rain received and the current month of the year, before resuming normal cycle time. The rain delay calculator can be used independently with fixed cycle irrigation, or along with calendars generated by the ISCDSP. The database for the rain delay dial can be found in the ISCDSP.
SASched
SAsched is a spreadsheet-based irrigation scheduling tool. It solves the soil water budget based on weather data and inputs relating to soils, crop and irrigation system specifications, indicating when irrigation will next be required. The SAsched soil water budget is based on sophisticated algorithms from the ACRU model and is capable of reporting run-off and deep percolation losses, in addition to estimating cane yield.
IrriEcon v2
Irriecon v2 is a spreadsheet-based tool used to assess different irrigation strategies by determining detailed capital, operating and marginal costs. The specific costs associated with sugarcane farming practices such as the application of fertilisers and herbicides, planting, harvesting and haulage together with irrigation systems, water and electricity costs are accounted for.
MyCanesim
This is a web-based sugarcane simulation tool linked to the full online SASRI weather and soil water database for simulating crop growth and water use for registered users. Applications include cane yield, cane quality and water use benchmarking, real-time irrigation scheduling and yield forecasting.
Try MyCanesim
MyCanesim Lite
This is available both as a web-based and mobile phone application. It is a sugarcane simulation tool linked to the Canesim model and the full online SASRI weather database for simulating crop growth and water use for limited sets of inputs. Applications include cane yield, cane quality and water-use benchmarking and limited yield forecasting.
Try MyCanesim Lite
WeatherWeb
SASRI has access to several automatic and manual weather stations across the sugar industry. All information gathered is stored in a weather database at SASRI. This information can be extracted in the form of maps, graphs or reports. Various levels of customisation can be applied to selections.
Visit WeatherWeb
RESEARCH
Water Management research focuses on the development of recommendations and advice to promote effective water management and deployment of associated technologies, both in terms of irrigation practices and surface water management. Visit SYSTEMS DESIGN & OPTIMISATION for more information.
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