Subirrigation field trial with treated residual water from Bavaria brewery

Reducing water shortages in agriculture with recycled industrial residual water

Rather than discharging the residual water produced by industry into surface water, the water can be used to tackle drought in agriculture. KWR, together with TKI Water Technology, has given concrete form to the reuse of treated residual water from the Bavaria brewery by neighbouring farm enterprises. Because of a more and more capricious climate, farmers are facing decreasing crop yields and increased irrigation needs. During the growing season, the soil moisture levels in the root zone are less and less adequate. By using industrial residual water to combat drought, rather than discharging it, unused, into surface water and the sea, one can reduce water shortages.

Improved moisture provision for crops

A subirrigation system, using the residual water from Bavaria’s water treatment process, was tested on a parcel of agricultural land next the brewery. The parcel has a relatively high elevation and the summer water table level drops to a depth of two meters or more below the surface. The results show that subirrigation raises the water table level and, therefore, soil moisture levels, to the point where the moisture provision for the crop is improved.

Contribute to building needed knowledge

Bavaria’s effort to return treated residual water to the surrounding environment shows how the industry is anticipating the increasing water shortages in agriculture. It fits in with developments in (climate) adaptation that involve the use of effluent streams (recycled water) for freshwater provision purposes. Such applications contribute to building knowledge needed to respond to all the associated opportunities and risks. KWR’s report, ‘Hergebruik van industrieel restwater voor de watervoorziening van de landbouw’ (Reuse of industrial residual water to meet agricultural water needs), details the technical and substantive aspects of the field trial carried out between 2015 and 2017, including the incorporation of the method into policy.