Effect of irrigation management on nitrate movement

Kimberley Althause will be investigating the effect of irrigation management on nitrate movement in a lettuce crop as part of her final year of an undergraduate degree at the University of Southern Queensland.

Kimberley will conduct field trials and nutrient modelling to investigate the movement of nitrate in soil under a drip irrigated horticultural production system. The aim is to then develop recommendations on strategies to improve the irrigation and fertigation management to improve fertiliser use efficiency and minimise drainage.

Recent Activities

This project will be undertaken from November 2008 to February 2009.

Aims

The aim of this project is to identify fertiliser and irrigation management practices which maximise nutrient use efficiency and minimise losses of nutrients and water to the groundwater system in commercial lettuce
production systems. The hypothesis of this research is that it is possible to reduce nitrogen applications without affecting lettuce yield and quality through better irrigation and fertiliser management. The project will
involve assessing nitrate movement under a drip irrigated lettuce crop and conducting modelling to evaluate the effect of irrigation and fertigation strategies on nitrate movement.

Background

The management of high value horticultural crops commonly includes the application of nutrients with irrigation water. However, depending on the soil properties, fertigation and crop management practices there is the potential for highly mobile nutrients (e.g. plant available nitrogen (nitrate) to be moved below the rootzone by irrigation drainage. This loss of nutrient from the rootzone is both a cost to the producer (through increased fertiliser requirements) and a potential contaminant of local groundwater systems.
Lettuce plants are shallow rooted and are easily water stressed. Relatively high levels of nitrogen are also commonly applied to ensure crop quality. Hence, there is the potential for significant leaching of nitrate out of
the root zone in lettuce production systems.

Publications and Resources

None listed

Citation

Land & Water Australia. 2009. Effect of irrigation management on nitrate movement. [Online] (Updated March 8th, 2010)
Available at: http://lwa.gov.au/node/2784 [Accessed Wednesday 10th of April 2013 09:19:44 AM ].