Application of a New Web-Based Tool(CropWaterUse) for Determining Evapotranspiration and Irrigation Requirements of Major Crops at Three Locations in Queensland

Abstract

Decreased water availability in many areas has created the need to make more efficient use of limited water resources. To maximize production and profits, growers need to make decisions regarding planting date, crop type, planted area, and irrigation management, which are affected by the amount of water available. Therefore, they need to know how much water is needed to grow a particular crop, which they currently estimate in most cases based on previous experience. However, crop water requirements can vary significantly, among other things, with crop type, season, location, planting date, and available water, which could make it inappropriate to extrapolate previous experiences to future planning. Also, occasionally growers may want to grow unfamiliar crops, which can further complicate planning. Growers and consultants need reliable estimates of crop water requirements to make irrigation decisions aimed at improving water use efficiency and profits. A current challenge is that growers’ perception of crop water requirements for particular crops and corresponding irrigation scheduling practices are based on historical weather patterns. These weather patterns are likely to change in the future if climate change and climate variability predictions prove to be true (Howden et al., 2007; IPCC, 2007), leading to changes in planting times and crop growth patterns. Growers could benefit from new tools to help them anticipate and adapt to the effects of these potential changes.