Irrigation scheduling Decision Support Systems (DSS) have seen poor uptake despite proved usage benefits. The failures of some previous systems with proven model accuracy and water savings ability have been attributed to interface difficulties and inappropriate information for end users. Use of the mobile phone Short Messaging Service (SMS) text messages was trialed as an interface to overcome these difficulties. Irrigation system dripper run time scheduling advice was sent daily to 72 Australian irrigators' mobile phones from a water balance system called IrriSat SMS. Irrigators sent back information on irrigations and rainfall, also via SMS, to update the water balance. This trial showed that a complex, water balance-based, DSS could rely on SMS as the sole interface. All 72 irrigators involved were content to receive messages daily for the entire growing season (200 days). A measure of engagement and utility of the system was determined by those who returned their irrigation and rainfall data, 45 sent in their data all season, 13 for half the season and 14 never sent in any data. Thus we infer that 45 users (63%) found the SMS system of enough utility to use for the whole season. Also, at end of season, 6 of the 13 who had stopped half way through said that in retrospect they wished they had not. Thus overall 80% of irrigators found the system useful. User interview data showed the simplicity of use, advice and the prompting effects of intrusive delivery (phone ringing) were key features in the resultant strong engagement of irrigators. Success also relied on appreciating that irrigators will only use objective decision support advice as one element in a set of decision making tools that include subjective and unquantifiable elements, such as plant appearance. This strong uptake reverses the trend in irrigation decision support which has seen poor uptake of sophisticated systems that produce comprehensive scheduling support but which are, or are perceived to be, complex and time consuming to use. Additionally, high participation rates show that much model input data may be collected from irrigators via SMS so it can be used as a very cheap bi-directional communication channel.

Increasing water scarcity, higher evapotranspiration rates and reduced rainfall have generated a need for fundamental improvements in irrigation water use efficiency. Evaporation is a significant component of the total evapotranspiration (ET) and high evaporation losses reduce the amount of available water for transpiration, resulting in reduced plant water availability and hence increased irrigation. In order to increase transpiration relative to evaporation and with enhanced pressure on water resources, a reduction in evaporative losses would lead to improved water use efficiency. In order to access the magnitude of soil evaporation losses in semi-arid vineyards and its effects on water use efficiency extensive field trials were carried out to quantify soil evaporation losses. The magnitude of soil evaporation was determined using direct and indirect measurements on a bare soil and in a commercial vineyard.