STELZNER® agricultural measurement systems

Determining the water balance

The BWK 2000 is a measuring instrument for determining the volumetric water content of mineral soils at different depths.
Thanks to the robust stainless steel lance and the aluminium housing which protects against moisture and dust, the BWK 2000 can be used in rough conditions. The sensor at the tip of the lance works according to the FDR (Frequency Domain Reflectory) principle; it determines the volumetric water content by using a high measuring frequency, with only a slight influence from the salinity of the soil. Furthermore, by selecting different calibrations, precise measurements can be made even when the soil types change. In addition to the volumetric water content, the salt content / conductivity of the soil and the temperature in the soil are also measured with each measurement. These values are stored in the integrated data logger.

The measured values recorded in this way can be transferred directly to the PC using a USB cable. The measurements of salinity, conductivity and temperature take place directly at the tip of the sensor. This enables the precise determination of these parameters at different soil depths.
The ability of soils to absorb moisture and then make it available to plants varies greatly depending on the different soil types. In general, sandy and humus-filled soils can provide significantly more plant-available water during wetter conditions, while loamy soils or clay soils have greater water-holding capacity during dry periods. By combining the knowledge of the soil texture together with the measurement of the volumetric water content in the soil using the BWK 2000, the supply of plants with moisture can be optimally monitored and adjusted.

Application areas:
The BWK 2000 is well suited for measuring at depths of up to 90 cm. It is preferably used in tree nurseries, vineyards, vegetable growing, for special crops such as berries and asparagus, in arable farming, and in urban green zones. The soil type (sand, loam, clay) can be set on the display. The measuring depth can be determined by referencing the markings on the stainless steel lance. You must work at the same depth if you want to compare the measured soil moisture values with each other. In order to meaningfully determine the volumetric water content, we recommend carrying out several measurements and then averaging the measured values obtained (similar as with soil samples).

There is an LCD for the display. The device is easy to calibrate.