IrriCheck's Irrigation Scheduling System

Irricheck offers the following:

  • Irrigation systems
           Supply of Irrigation equipment
           Evaluation of current irrigation systems
  • Irrigation scheduling
           Irrigation scheduling software
           Supply of continuous logging probes
           Supply (manufacturing) of automatic rain guages
           Supply (manufacturing) of Irricoms, which communicates by GPRS modem between probes,
           rain guages and weather station and the Irricheck web server 
           Irrigation scheduling services throughout South Africa


Since 1994 Irricheck the Irrigation scheduling system is developed to the point where it is clearly distinguished from other systems on the following attributes:

  1. Full service to clients by fully trained consultants in all Irrigation areas
  2. Fully automatic monitor system for soil moisture with contnuous logging capacitance probe, applied irrigation or rain, weather data and weather forecast
  3. Fully automatic handling of all measured data
  4. In situ calibration of continuous logging capacitance to volumetric water content
  5. Full integration of all measured data and the other variables of the Crop-Soil-Climate system towards accurate irrigation recommendations
  6. The automatic delivery of Irrigation recommendations in the form of viewing on website, email or SMS to the person responsible for applying the irrigation, thus enabling managers to delegate routine scheduling to lower level personnal which do not need any knowledge of scheduling
  7. Automatic messages from the web based system to notify or warn all role players about any situation which needs attention
  8. Safety of delegating responsibilties thanks to continous access to full real time data for checking by managers
  9. Determining of crop factors for each crop on each field
  10. Determining of the maximum depletion level where stress initiates on each field


Widely tested and proven system

The irricheck System is currently used with outstanding results of water savings and increased yileds on at least 330 farms in all provinces in South Africa.

During 2011 the results which were achieved with the system at Kartsen Farms lead to a reward from the ICID (International Committee for Irrigation and drainage). 

During 2012 The Department of Water Affairs in South Africa rewarded the system with their award for the farming sector.  This reward was for water savings in the agricultural sector.  Although the measured water savings of about 30% on 350 ha table grapes at “Raap en Skraap” nearby Onseepkans (South Africa) was remarkable, the real value as shown in the table below was in increased water use efficiency. 



Additional boxes packed / unit of water

(compared to 2007, before system was introduced)

2008 26 %
2009 64 %
2010 36 %
2011 77 %
Average for 2009, 2010, 2011 59 %


The value of accurate scheduling is more so from increased yield and quality through the elimination of periodic water stress by over or under irrigation as from savings in water and electricity costs.  In general the value of a 10% increase in yield is 10 times more than that of a 20% saving on water and electricity costs.


With this in mind: 


How can you afford not to use the best available technology

in Irrigation scheduling ?


How the system works

The scheduling system automatically acquires the following data

  • the predicted weather
  • the hourly measured soil moisture at six depths (Capacitance probes)
  • the actual weather data (temperature, humidity, windspeed, wind direction, rain)
  • the measured irrigation


The Irricheck Scheduling Program runs a hourly simulation model to integrate all these measured data with the following variables and parameters of the Crop - Soil - Atmosphere System in order to simulate the expected water use and resulting soil water depletion for the week ahead:

  • The Field capacity of each of the six layers of the soil profile
  • The rooting depth of the crop and the soil depth
  • The properties of the irrigation system, such as type of irrigation, application rate, irrigation efficiency, extend to which foliar is wetted, etc.
  • The expected evaporative demand for the week ahead is calculated using the Penman-Montieth equation and the predicted weather data
  • The actual evaporative demand for the past is calculated using the Penman-Montieth equation and the actual weather data
  • The expected crop coefficients for the different stages of the growing season
  • The % cover of mulch, which will reduce evaporation and intercept rain and irrigation
  • The % cover of  weeds, which will use additional water and intercept rain and irrigation

In order to generate a recommended irrigation schedule for the week ahead, the program apply the simulated water use with the management decisions such as:

  • the depths for the top- and bottom soil
  • allowable depletion levels for the top- and bottom soil
  • several other options on irrigation strategies

 The Irricheck System 14Oct2012

The Irrigation Recommendation

The Irricheck program recommends the timing and quantities of the required irrigations to meet the simulated water use of the crop on each field.

 Irricheck recommendations 14Oct2012 small


The manager can check the results whenever it suits his schedule, because all the data is summarized in graphs on a single screen and is saved automatically.  The continuous data on hourly measured soil water, indicating every irrigation, showing wetting depth and the summarized depletion in the top- and bottom soil together with the actual, predicted and long term average evaporative demand.


 Irricheck graphs 14Oct2012 small80

 During the execution of the recommended irrigation, operators make notes on the printed recommendation, indicating reasons for any deviations from the recommendated plan. This record is filed next to the computer enabling the manager and the consultant to interpret deviations from the plan. 


The system is serviced by Irricheck’s consultant, who is responsible for the following:

  • Setting up the program, the weather station and the general options in the program
  • Setting up fields with info of the crop, soil, probes, irrigation system, weather data and weather forecast areas, etc
  • Setting field capacity levels for each measured layer and refining it regularly as it varies slightly over time
  • Calibrating the % probe readings to mm/m of water in each field 
  • Setting application rates and other irrigation system variables
  • Setting crop coefficients and refining them according to measured water use and measured evaporative demand
  • Determining (for each field) the depletion level where first crop water stress occurs, which should be the maximum depletion level for irrigation.
  • Ensure that the farmer and his operators understand the system
  • Ensure that important information is noticed by the farmer and his operators 

Other outstanding features of the system:

  • The ability to determine the crop coefficient. The system measures both components of the crop coefficient, which is the ratio between the water used and the evaporative demand for the same day. The crop coefficient is therefore actually measured daily.  Therefore the normal process which is followed during research, is executed on each field. Therefore in the graph below (in the second graph from below on the right) the actual crop coefficient is the ratio before water supply becomes limiting and the ratio starts to drop.  
  • The ability to determine the depletion level at which crop water stress initiates, which is the maximum refill amount for the specific crop on the specific soil. This information is crucial for optimising irrigation efficiency by minimising evaporation losses through longer irrigation frequencies with higher irrigation quantities. In the Actual Use/ED (ED = Evaporative Demand) graph below it can be seen how the ratio stays constant for a few days until supply becomes limiting. After that the ratios declines, indicating stress.  In the top soil graph it can be seen that this happens when the deficit exceeds 20mm.  The water use includes evaporation losses, which explains the higher ratios shortly after irrigations.   The data in the graph was measured without using the Irricheck Scheduling program.  The information was revealed after importing the data into the Irricheck software. The data clearly indicates that the irrigation intervals is too long and that stress is induced by the end of each irrigation interval.  These table grapes resulted in small berry size because they were so frequently stressed, which could have been avoided by efficient scheduling. 

 Irricheck Crop Factors and Stress 14Oct2012 small80

Communication features

 The Irricheck software contains numerous functions which enables farmers and consultants to utilise internet technology to enable and speed up the service functions of the consultant.  

  • The Irricheck Scheduling program can send the recommendation to users by SMS or email
  • Uploading and downloading of datasets to the Irricheck website: Especially when a physical visit from the consultant is not necessary or possible, the dataset can be uploaded very easily to Irricheck's web-site. The consultant can download it, check and refine it and upload it again. After downloading it again, the farmer can continue scheduling as normal.
  • Sending an email with a screenshot attached: A farmer can easily bring anything to the attention of his consultant by pressing the F2 function.  The program will prompt him to write a note and will automatically attach a screen shot to the email which is sent immediately to the consultant.
  • SMS notifications: The program can notify anybody, according to the clients needs of several different situations, which need attention. This function helps to ensure that certain urgent situations are attended to quickly. Examples: SMS the technician if a probe battery should be replaced, SMS the supplier of the probe if the probe readings are unstable, SMS the manager if the deficit in a field is exceeding the allowable depletion with more than 20% (variable to be set).


The web based Irrigation Scheduling database

This is the way for the future.  The measured data from each Irricheck probe, the rain/irrigation guage and the weather station is sent automatically by a GPRS modem to the Irricheck web-erver.  The Irricheck program runs on the Web-server and generates the recommendation and the summarizing graphs of each field and publish it on the Irricheck website where it is continuously available to all registered users of the client.   In this way the scheduling can be delegated to a lower level manager and the results can be supervised by any manager anywhere globally, while the consultant is enabled to supervise an refine the proses all the time.


Irrigation Scheduling system for Corporate clients

In big farming enterprises, where several farms in different areas are managed, there is a need to share the data between lower- middle- and top level management. In Irricheck's experience, we have found that it is best to decentralise decisions together with the responsibility. This is done by empowering lower levels of management to make accurate irrigation scheduling decisions. This can be done safely if middle and top management can check frequently, using the continuous data.


With this in mind, the following application of the system is suggested:

  • On each farm the Irrigation Scheduling program is operated in the normal way, but with the following two features activated. The program will automatically upload its data every time when new probe data is imported. The dataset is set up by the consultant in run-only mode. In this mode the farm manager will not be able to change any settings. It will be the consultant's sole responsibility.
  • The data on the web-based database then always contains the newest data. A Web based Irrigation scheduling program loads the newest recommendation and the graph containing all data of every field. Any registered user can see the data whenever he/she needs to. This data can also be made available to other management systems like GPS based prescision farming database systems.
  • The consultant, whether internal or external to the company, can download the newest dataset for any farm at any point in time in order to check the data and refine the settings. He uploads the dataset afterwards and the Irricheck Program on the farm will automatically detect it and download it.
  • The system can send notifications to anyone, reminding them of situations that need their attention.


To view Scheduling data for your farm please log in below.


2013 - Irricheck Irrigation Scheduling .