Monitoring the temporal evolution of the soil structure of three innovative production systems in the field

Nowadays, it becomes urgent to develop innovative production systems in order to meet tomorrow's diets while being more environmentally friendly. The impact of emerging alternative agricultural practices on soil structure and hydraulic properties is poorly known or studied. Hydraulic properties such as water retention curve and hydraulic conductivity are the basis for water status modelling in soils. These properties are generally obtained by one-time laboratory measurements on a soil sample. Thus, the retention curve which establishes a relationship between water content and water potential is usually considered as constant in time. However, this single retention curve cannot imitate the water retention characteristics of soils under natural conditions in dynamic situations.
In this study, three innovative production systems are instrumented for hydrological monitoring. The three systems are designed to disrupt current agronomic trials and aim to produce the ingredients of tomorrow’s diets. The innovative systems are pesticide-free and have long-term rotations of 8 years with intercrops. The first system integrates the animal out of soil with only importations and exportations of animal products, the second in an agro-ecological interaction with grazing periods and the third is vegan. These systems are implemented in two different temporalities on the parcels of the University of Gembloux Agro-Bio Tech on a typical loamy soil of northern Wallonia.
The innovative systems were instrumented with 24 Teros 12 water content sensors and 24 Teros 21 water potential sensors from MeterGroup. Both types of sensor are robust, highly accurate and require little maintenance. The Teros 12 probes also measure soil temperature and salinity. Potential probes can measure potential over a wide range of values from -9 to -2000 kPa. All probes are connected to MeterGroup's ZL6 data loggers which allow real-time data collection. The water content and potential probes are placed in parallel in the first three soil layers at 30, 60 and 90 cm depth in 8 plots.
The simultaneous determination of both water content and water potential over time allows the temporal evolution of the hydrodynamic properties to be captured. Soil water retention and hydraulic conductivity curves will be measured over time under natural conditions for the three innovative systems. This monitoring system will then make it possible to quantify the temporal evolution of the structure of a loamy soil under the effect of agricultural practices and climate conditions. The data obtained will be used to diversify the agricultural practices represented in decision support models. The first year' s results of the innovative monitoring systems will be presented at the SSSB thematic day on soil structure and compaction.