This research presents a WSN computer system model applied to precision irrigation, specifically for conditions in which sensor nodes may be located far from the coordinator. The proposed model is based on a tailored hardware and software aiming to extend both sensor nodes and WSN lifetime. The coordinator is aware of its sensor nodes’ available energy and such feature enables estimating the remaining lifetime of each sensor node. The so-called Sensor nOdes’ system for data acqUisition of Long range (SOUL) is the conceptual model for a sensor node hardware and software system design, concerning energy management and messages grouping, improving both sensor nodes and network lifetime. The sensor nodes were employed to monitor soil moisture and thus the SOUL computer system model was validated in field conditions. Sensor nodes lifetime was increased by 5.7 times when compared to a conventional use.

Assuming that a roughness meter can be successfully employed to measure the roughness on the internal surface of irrigation pipes, this research had the purpose of defining parameters and procedures required to represent the internal surface roughness of plastic pipes used in irrigation. In 2013, the roughness parameter Ra, traditional for the representation of surface irregularities in most situations, and the parameters Rc, Rq, and Ry were estimated based on 350 samples of polyvinyl chloride (PVC) and low-density polyethylene (LDPE) pipes. Pressure losses were determined from experiments carried out in laboratory. Estimations of pressure loss varied significantly according to the roughness parameters (Ra, Rc, Rq, and Ry) and the corresponding pipe diameter. Therefore, specific values of roughness for each pipe diameter improves accuracy in pressure losses estimation. The average values of internal surface roughness were 3.334 and 8.116 μm for PVC and LDPE pipes, respectively.