Influence of irrigation method on water use and production of perennial pastures in northern Victoria

Abstract

The irrigation of pasture for the dairy industry accounts for a large proportion of Australia’s total irrigation water use, particularly in the Murray–Darling Basin. Most pasture is irrigated using the border-check method. The dairy industry is under increasing pressure to use water more efficiently in response to water market reforms and restrictions on future irrigation water availability, creating interest in the potential of alternative irrigation methods. A field experiment was conducted at Tatura, Victoria, Australia between July 2000 and July 2002 to quantify the differences in water use, perennial pasture production and pasture composition under border-check, surge, sprinkler and subsurface drip irrigation. The experiment aimed to assess each irrigation method as it would perform under farm best management practices. Measurements included applied water, tailwater runoff, soil water status, dry matter production and botanical composition. This experiment found that sprinkler and subsurface drip irrigation used on average 2 ML/ha.year (17–23%) less water than border-check irrigation while maintaining or increasing pasture production, consequently having a significantly higher water use efficiency. Surface runoff was significantly reduced under sprinkler and subsurface drip irrigation. Surge irrigation had no advantages over border-check. Although some differences in pasture composition were observed between irrigation treatments, the trends were inconsistent from one season to the next. The high water use by gravity fed irrigation methods is attributed to a combination of higher evaporation and groundwater accessions.

Forage Options for Dairy Farms with Reduced Water Availability in the Southern Murray Darling Basin of Australia

“…Under the combination of flood or border-check irrigation systems and the cracking soil types, on which the vast majority of forages in the region are grown, the irrigator has the ability to control when irrigation occurs but has little control over how much irrigation water infiltrates at any given irrigation [92]. In this situation, deficit irrigation is limited to not irrigating for a given time period (such as either a part of or for a full irrigation season) or to increasing the time period between irrigation events.…”

Integrated analysis for a carbon- and water-constrained future: An assessment of drip irrigation in a lettuce production system in eastern Australia

“…Water savings can be quantified through field experiments and crop models (Wood and Finger, 2006;Khan et al, 2004Khan et al, , 2008aPeter DeVoil, pers. comm.).…”

Sustainable land and water management policies and practices: a pathway to environmental sustainability in large irrigation systems

“…These include improved water use efficiency (Wichelns, 1999(Wichelns, , 2002Molden et al, 2007) deficit irrigation (Bethune, 2004) and better irrigation practices (Wood and Finger, 2006); better crop choices (Ashraf and Saeed, 2006); integrated agroforestry and crop farming systems (Dunin, 2002;Turner and Ward, 2002); revegetation and tree plantations on barren lands (Hajkowicz and Young, 2002); conjunctive use of surface and groundwater (Kijne, 2006;Khan et al, 2007); and mechanical solutions such as improved drainage (Datta et al, 2004) and integrated approaches including evapotranspiration basins and biological concentration of salts etc. (Rundle and Rundle, 2002;Abdel-Dayam et al, 2004).…”