Following the outcomes of the 2nd stakeholder workshop that was that was held in October 2015, a field experiment was st up with the aim of testing the effectiveness of selected agricultural practices to recover the SOM of mineral soils.
Use of cover crops (CC) to provide continuous ground cover and living vegetation in the field has been selected as the most promising treatment.
The application of cover crops involves the alternation of autumn-winter cereals, rapeseed or other herbaceous crops with maize, soybean, sorghum etc. Cover crops that are sown after the main culture are neither fertilized nor treated with pesticides during growing, while at the end of the crop cycle they are buried as green manure in order to improve soil organic matter content, nutrient cycle and finally soil fertility. Organic carbon inputs due to the continuing presence of plant root systems is also promising to increase soil organic matter due to a lower decomposition rate than other organic sources (e.g., residues, slurry)
Conservation agriculture (CA) was selected as a secondary treatment to test in the field, since widely endorsed for preserving soil structure and enhancing SOM content.
Recently, studies that involved deep soil sampling (> 50 cm) showed contrasting results on the benefits of conservation agriculture for C sequestration purposes, although SOC accumulation in the soil profile is only one of the multiple ecosystem services provided by CA (increase of aggregate stability, reduction of soil water erosion and P loss, etc.).
A field that is managed accoridng to conventional practices (CV) is used as a control.
A 3-year crop rotation has been established for all treatments: winter wheat, followed by soybean and finally maize . In CA and CC, a continuous soil cover is guaranteed by cover crops that are grown between the main crops: sorghum during spring-summer and barley in autumn-winter. The soil remains bare between the main crops in CV.
Thanks to the collaboration of Veneto Agricultura, which houses the field trial in Sasse Rami farm (located in Ceregnano, RO), and the technical assistance of DeltaOhm, everyone can monitor in real time the effects of the different treatments on the soil conditions!
A meteorological station has been installed to integrate the observations from the soil monitoring stations with atmospheric data in order to calculate the water balance and the nitrogen balance and therefore predict the nutrients movement.
A wireless system in ISM band has been designed to connect the weather station to the dataloggers that are placed in the different plots.
The instruments installed in each stations are:
1. Multi-sensor probes to estimate soil moisture, soil temperature and soil electrical conductivity at three different depths (10 cm, 30 cm and 60 cm).
2. A phreatimeter for measuring the water table depth and sampling groundwater.
3. A suction cup at a depth of 60 cm to sample the soil solution and understand movement of solutes (especially nitrates) in the different treatments.
In collaboration with