The Leibniz Center for Agricultural Landscape Research (ZALF) in Müncheberg intends to set up a research platform to strengthen internal and non-institutional cooperation while increasing third-party funding and international visibility, advancing technology in the agricultural and environmental sectors in cooperation with enterprises (SMEs).
In order to enable controlled and controllable experiments in undisturbed soil over long periods of time, the procurement of an ecotron system is planned. In order to determine the naturally occurring heterogeneity of the soils and plants studied, it is necessary to procure 3 ecotrons, each of which has 3 individually weighable lysimeter containers. The atmospheric unit of the ecotrons should be gas-tight and controllable in terms of temperature, humidity, and PAR, and have a fresh air supply and exhaust air. The assembly of important physiological and ecohydrological sensors and sampling options (e.g. soil moisture, matrix potential, temperature, continuous in-situ stable water isotope measurements) in the lysimeter vessels is absolutely necessary (see detailed description under performance description).
The plant is to be set up and operated in a building at the Paulinenaue research station. This building is not air-conditioned, but it has electricity and the possibility for water connections and ventilation. The floor area of the room to be used is 5.9 m x 4 m. When operating the ecotrons, the outside temperatures in summer are not planned to fall below or the outside temperatures in winter will not exceed 5 degrees DC. The restriction here is severe sub-zero temperatures, as frost-free operation must be guaranteed throughout.
Delivery, assembly and commissioning of 3 ecotrons, which should have the following performance characteristics (minimum requirements):
Soil habitat:
Each ecotron should have a soil habitat, which in principle can be converted between installing lysimeter containers of 200 mm (3 per ecotron) and 500 mm (1 per ecotron) in diameter. Initially, 3 lysimeter containers of 200 mm per ecotron should be installed. The ground habitat should have an inspection door. The lysimeter vessels should be 900 mm deep. The lower edge should be tension-controlled and temperature-controlled (limited winter operation, ground heating unit and cooling). The actual height of the lysimeter vessels should be adjustable in stages: from 300, 600 to 900 mm.
Each of the lysimeter vessels should be able to be weighed separately and the water level must be adjustable separately. Each of the lysimeter vessels should have the following sensory equipment at 2 depths (10 and 50 cm) (i.e. 6*3=18 measuring points in total):
- combined soil moisture and temperature probes (0 to 60% +/- 3% soil moisture, -40 to +80 degrees C +/- 0.2 temperature)
- Tensiometer (full range, measuring range from -100 to +1500 kPa)
- ORP electrode according to Mansfeldt and Ag/AgCi reference for measuring the pH value
- In-situ sensors for monitoring the stable isotope signature of soil water and multiport as well as control software for connection to a Picarro isotope laser spectroscope (WIP system according to Volkmann et al., 2014)
- Soil collection port of 10-15 mm diameter and 20 mm length per lysimeter piece
- Additional sensor feed-through ports for later retrofitting (63 pieces)
Atmospheric habitat:
The atmospheric habitat of each ecotron should be 610 mm in diameter and 1500 mm in height, equipped with an inspection door. The atmospheric habitat should be gas-tight and should be used simultaneously with outlet openings (incl. dust filter) and exhaust ventilation (so-called open through-flow system). The lighting will be provided by dimmable high-performance LED lighting with simulation of daylight and photosynthetically active radiation of up to 2500 mümolm-2s-1. The air control of the atmospheric unit is to be realized in flow by means of fresh air supply and optional drying.
The following sensors should be included:
- automated irrigation system
- 1 height-adjustable humidity and temperature sensor
- 1 sensor for measuring photosynthetically active radiation (PAR)
- IP camera 4K
- Additional cable entry ports to be able to pass gas measurement hoses (up to 1/4 inch hose thickness, 10 pieces)
- 4 in-situ sensors for monitoring the stable isotope signature of atmospheric water vapor and connection to the above-mentioned multiport as well as control software for connection to a Picarro isotope laser spectroscope (WIP system according to Volkmann et al., 2014)