Soil–water and solute movement under precision irrigation: knowledge gaps for managing sustainable root zones

Abstract

1Precision irrigation involves the accurate and precise application of water to meet the 2 specific requirements of individual plants or management units and minimize adverse 3 environmental impact. Under precision irrigation applications, water and associated solute 4 movement will vary spatially within the root zone and excess water application will not 5 necessarily result in deep drainage and leaching of salt below the root zone. This paper 6 estimates that 10% of the irrigated land area (producing as much as 40% of the total annual 7 revenue from irrigated land) could be adversely affected by root zone salinity resulting 8 from the adoption of precision irrigation within Australia. The cost of increases in root 9 zone salinisation due to inappropriate irrigation management in the Murray and 10Murrumbidgee Irrigation Areas was estimated at AUD245 m (in 2000/01 dollars) or 13.5% 11 of the revenue from these cropping systems. A review of soil-water and solute movement 12 under precision irrigation systems highlights the gaps in current knowledge including the 13 mismatch between the data required by complex, process-based soil-water or solute 14 simulation models and the data that is easily available from soil survey and routine soil 15

Simulation of salt and water movement and estimation of water productivity of rice crop irrigated with saline water

“…Alternatively, scientists and water and environmental managers increasingly use computer models to study the complex processes in the soil (Phogat et al 2000(Phogat et al , 2009Raine et al 2007) to provide management and planning guidance. A wide variety of models exists for simulating water flow and solute transport in the vadose zone.…”

Advanced Monitoring and Management Systems for Improving Sustainability in Precision Irrigation

“…Precision irrigation is an evolving field with active interest by both industry and academic researchers. It is conceptualized by some researchers as the use of efficient irrigation application systems, whereas others view it as the variable application of irrigation based on predefined maps or sensor feedback [10]. Smith et al [11] suggested that 'precision' involves the accurate determination, quantification of crop water needs and the precise application of the optimal water volume at the required time.…”

Impact of Irrigation Strategies on Tomato Root Distribution and Rhizosphere Processes in an Organic System

“…Innovations in irrigation technology usually focus on optimizing timing, wetting patterns, and intensity of irrigation to increase resource use efficiency with the preset assumption of crop root distribution. However, the plasticity of root systems and the interactions between roots and rhizosphere microbes that mediate plant nutrient uptake and soil nutrient cycling have been largely neglected (Raine et al, 2007). Our study tackles this knowledge gap by assessing responses of root traits and rhizosphere processes to moisture and nutrient patterns determined by irrigation strategies in an organic system and provides insights into their relationships with plant nutrient uptake, yield, and soil nutrient cycling.…”

“…In agroecosystems, irrigation practices are designed to deliver water to crop roots, but the spatiotemporal dynamics of resource availability are rarely perfectly coupled with plant demand (Howell, 2001). This mismatch arises from limited research on how roots and rhizosphere processes respond to water and nutrient dynamics that are shaped by irrigation methods over space and time (Raine et al, 2007). The neglect of root and rhizosphere interactions during the implementation of new irrigation practices, especially when management changes are made based on experience or external reasons, can lead to inefficient use of costly inputs and damaging losses into the environment (Vázquez et al, 2006;Thompson et al, 2007).…”