This Technical note summarizes some experimental results concerning the effective strength parameters (c'-φ') and the saturated coefficient of hydraulic conductivity (k) of silty and sandy soil specimens that have been compacted at different compaction degrees. The tested soils were used for the construction/refurbishment of existing levees. The effective strength parameters were obtained from conventional triaxial loading compression tests. Specimens were compacted at different percentages of the maximum (optimum) dry density and at the optimum water content. The maximum dry density and optimum water content were determined according to the Modified Proctor method. Specimens with different percentages of the maximum dry density at the optimum water content were obtained in the Proctor mold by using different compaction energy. Levees (and more generally any type of earthworks) can increase their water content because of intense rainfall or repeated floods. Therefore, the strength parameters of fully saturated specimens have also been experimentally determined. The saturated coefficient of hydraulic conductivity has been inferred from variable head permeability measurements that were performed in specially equipped oedometers. This coefficient has been measured in the case of specimens compacted at different compaction degrees and at different initial water contents (i. e. saturation degrees). The effect of compaction degree on strength and permeability parameters has been shown. As for the strength parameters, the effect of partial saturation (suction) has also been shown.

<p>In this work, we propose to transfer a soil moisture-based wireless sensor network (SM-WSN) to support the reduction of irrigation water consume in the Tuscany region (Italy). The SM-WSN was designed and validated in a commercial pear orchard during two growing seasons (2019-2020) in which the smart irrigation strategy was implemented and applied.</p><p>Initially, the micro irrigation system was assessed based on its performance in terms of water distribution uniformity (DU) evaluated with field measurements of emitter flow rates. Then, a zoning analysis was carried out to divide the orchard into homogeneous areas according to the normalized difference vegetation index (NDVI) detected with unmanned aerial vehicle (UAV) and GIS tools. These areas were used to define the topology of the SM-WSN and to investigate how water distribution uniformity can affect the vigour of the trees. A total of 6 “drill & drop” capacitance probes (Sentek Pty Ltd, Stepney, Australia) were installed in the field, after following a simplified laboratory calibration procedure. The hardware and the smartphone-based application, AgriNET, used to download from remote the sensors’ readings were provided by Tuctronics (Walla Walla, Washington, USA).</p><p>Assuming that the zoning outcome was only associated with the soil spatial variability, the effect of DU on the vigour of the trees has been identified. Moreover, unlike the ordinary irrigation scheduling applied in the farm, the smart system allowed maintaining the soil water content within a pre-defined optimal range, in which the upper and lower limits corresponded respectively to the soil field capacity and the threshold below which water stress occurs. Based on the smart irrigation management, a water-saving up to 50% of the total water supplied with ordinary scheduling was achieved during both the investigated growing seasons. Moreover, the quality of the productions (i.e °Brix, fruit size and firmness) were in line with the standard required by the farmer. The adoption of the new technology, aiming at identifying the most appropriate irrigation management, has the potential to generate positive economic returns and to reduce the environmental impacts.</p>

<p>New technologies in agriculture present the opportunity to create intuitive and user-friendly decision support systems, and to improve the productivity of the systems requiring water and energy. In the last few years, the adoption of these technologies have been increasing through third mission activities, and the collaboration between researchers, consultants, agri-food managers and farmers.</p><p>The general objective of the proposed dissemination activity carried out by the AgrHySMo laboratory of the University of Pisa, was to transfer a soil moisture-based wireless sensor network (SM-WSN) to a commercial pear orchard named Illuminati Frutta (Arezzo, Italy), for the feedback control of irrigation.</p><p>The plan of the third mission activity was designed by the following phases: i) the team evaluated the hydraulic performance and management of the irrigation system in the pear orchard; ii) the use of proximal sensing provided the NDVI for the biophysical characterization of the crop in a pilot area extended thirteen ha; iii) the open-source QGIS suite program was used to elaborate the collected images, to assess a zoning analysis, and to discretize homogeneous areas inside the orchard. These zoning maps were used to define the topology of the SM-WSN.</p><p>The orchard was characterized by four homogeneous zones, inside which at least one sensor of soil water content (FDR Drill and Drop probe, Sentek Inc.) was installed. A total of 6 probes were installed in the pilot area. The hardware and the smartphone of the dedicated sensor network applications, AgriNET, were provided by Tuctronics (Walla Walla, Washington, USA). The measurements of volumetric soil water contents are sent to a platform using the MODBUS RTU protocol interfaced with a communication board and then delivered, using the cellular 3G data network, to a MySQL database operated by AgriNET/Tuctronics accessible from the web. According to the ordinary scheduling of irrigation, the expert system allowed the farmer to maintain the soil water content within a pre-defined optimal range, which upper limit corresponds to the soil field capacity and the lower is the threshold below which water stress occurs. During the first experimental growing season, by considering the results obtained in the pilot plot, compared with the ordinary irrigation scheduling the farmer saved up to 35% of the water and energy supply. In the future, the proposed feedback control of irrigation protocol will be extended to the entire farm. Thus, the adoption of this new technology aimed at identifying the most appropriate irrigation management, have the potential to generate positive economic returns and to reduce the environmental impacts.</p>