Swiss company Plantcare aims to digitize agriculture using the IoT

By Aalyia Shaukat, contributing writer

A Switzerland-based company, PlantCare , has developed a smart irrigation system that autonomously monitors soil moisture levels and waters plants accordingly. The IoT system has proven to reduce water waste by up to 30%.

Wireless sensor networks (WSNs) have been a key enabling technology in the IoT revolution serving commercial, industrial, medical, and even agricultural realms for smart M2M communications. Newer, low-power wide-area network (LPWAN) architectures fit a unique niche of wireless communications that can achieve link distances beyond 10 km, while end devices consume extremely low powers (10 to 20 dBm), allowing for battery lifetimes up to 10 years. The wireless network technology in PlantCare’s system uses both the 868-MHz and 2.4-GHz European ISM bands, which are unlicensed and, therefore, more cost-effective. The agricultural system employs clusters of sensor nodes that can be placed within a maximum 200-m radius per irrigation zone. For fields that are scattered around a farm kilometers away, range extenders (REXes) or repeaters are employed that allow for a 3-km range extension. Up to 12 sensors can connect to one REX wherein each REX can connect to four other REXes. This way, PlantCare is able to support many farm topologies that require both short-range and long-range connectivity.

Their patented water sensor leverages the Micro Heated Pulse (MHP) method for soil moisture monitoring wherein the sensor emits a short burst of heat, which is allowed to cool by the ambient environment in order to help detect temperature differentials in the soil. The variations in temperature correlate directly with the amount of moisture in the surrounding earth. The sensor includes a hydrophilic felt tip that shields the sensitive internal electronic circuitry as well as sucks up the moisture of the surrounding soil for moisture analysis. The sensor node then communicates with other intelligently placed sensors in the region to assess the relative moisture in the area. The system calculates the optimal time to water according to the plant’s specific water requirements and automatically adjusts the run times according to their growth stages and seasonal temperature fluctuations.

An additional benefit is that the hardware is specifically designed for minimal maintenance. The felt tip on the sensors are able to retain their properties for several years while the power consumption of sensor nodes is minimal ― two 1.5-V AA batteries or D-cells could provide power to a sensor for up to one year, provided that the time between two measurements is one hour. For the more power-hungry control unit and water pump, solar energy harvesting is used through photovoltaic cells (PVs) to enable constant operation without the concern for battery replacements.

The Federal Office for the Environment (FOEN) conducted research with the PlantControl CX system back in 2013 on a 15-acre farm where different soil moisture regimes were irrigated. The results showed over 30% water savings with only 64,100 gallons per acre used as compared to the previous average of 203,000 gallons of water. With nearly 70% of usable fresh water dedicated for watering animals, watering agricultural crops, and for crop processing, this could be the beginning of a significant turning point in smart water usage. Systems such as this could spur positive global impact for minimizing water waste considering that water poses one of the largest risks for humanity, according to a World Economic Forum (WEF) report in 2014.

Source: PRNewswire,  Plant-care.ch,  patents.justia.com