On September 21th, a workshop organised by the Dirección General de Desarrollo Rural y PAC (DGDRPAC) and the Instituto Valenciano de Investigaciones Agrarias (IVIA) was held in Alginet (Valencia, Spain). Fifteen technicians and growers from the “Acequia Real del Jucar”, one of the biggest irrigation communities in Spain (25,000 irrigators) attended. For the workshop, 4 orchards of persimmon and citrus with different soil textures were selected. All the orchards, which are located in Alginet, were visited.
During the workshop, it was showcased an innovative technique, which allows to measure the soil moisture and nitrate content variation over time, assess water quality and increase the water and nitrogen use efficiency of field crops with drip irrigation.
At the visits, the technique was demonstrated real time. To gain more information to help to optimise the fertigation recommendation, soil solution extracted from suction samplers. The samplers installed in the soil closed to drippers in two depths 40 and 70 cm and every 15 days were sampled. Electrical conductivity and nitrate content were measured on-site by a handle EC-meter and a colourimetry-based rapid analysis device, respectively. Since the levels of the nitrate applied through the fertigation are known, we compared it with the levels on the soil solution and allowed us to estimate the crop requirements. An increase in the nitrate levels extracted from the deeper soil layers (70 cm) indicates an excess of nitrate supply and requires to adjust the fertigation solution. To improve the irrigation management and match crop water demand to supply, a data logger with a GPRS connection and capacitive EnviroSCAN-Sentek sensors, monitored the soil water content at a depth of 20, 40 and 70 cm and assessed the drainage. Plant (leaf) water potential measured by a pressure chamber used to estimate plant water demand to avoid hydric stress.
After the fieldwork, the data collected by the system were visualised and interpreted in the control centre of the Acequia Real del Júcar (Guadasuar). There, the attendees show how the analysis of these tests and the knowledge of certain parameters allow us to obtain very useful information for adjusting the irrigation and fertilizer scheduling.
The day finished with demonstrations of technology exchanged in FERTINNOWA. The results of the project are being spread in the area of Valencia.