title: Set up of an automatic water quality sampling system in irrigation agriculture.
abstract: We have developed a high-resolution automatic sampling system for continuous in situ measurements of stable water isotopic composition and nitrogen solutes along with hydrological information. The system facilitates concurrent monitoring of a large number of water and nutrient fluxes (ground, surface, irrigation and rain water) in irrigated agriculture. For this purpose we couple an automatic sampling system with a Wavelength-Scanned Cavity Ring Down Spectrometry System (WS-CRDS) for stable water isotope analysis (δ2H and δ18O), a reagentless hyperspectral UV photometer (ProPS) for monitoring nitrate content and various water level sensors for hydrometric information. The automatic sampling system consists of different sampling stations equipped with pumps, a switch cabinet for valve and pump control and a computer operating the system. The complete system is operated via internet-based control software, allowing supervision from nearly anywhere. The system is currently set up at the International Rice Research Institute (Los Baños, The Philippines) in a diversified rice growing system to continuously monitor water and nutrient fluxes. Here we present the system's technical set-up and provide initial proof-of-concept with results for the isotopic composition of different water sources and nitrate values from the 2012 dry season.
authors.affiliation: Institute for Landscape Ecology and Resources Management, Research Centre for BioSystems, Land Use and Nutrition (IFZ), University Giessen, Heinrich-Buff-Ring 26, Giessen 35392, Germany. emanuel.heinz@umwelt.uni-giessen.de.
authors.forename: Emanuel
authors.initials: E
authors.lastname: Heinz
authors.forename: Philipp
authors.initials: P
authors.lastname: Kraft
authors.forename: Caroline
authors.initials: C
authors.lastname: Buchen
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Frede
authors.forename: Eugenio
authors.initials: E
authors.lastname: Aquino
authors.forename: Lutz
authors.initials: L
authors.lastname: Breuer
mesh_terms: D057914:Agricultural Irrigation / Q000592:standards*; D004784:Environmental Monitoring / Q000379:methods*; D060753:Water Quality; D014881:Water Supply / Q000592:standards*