Presenting a technological alternative to the uncertainty of climate change and, with the support of the Fundación para la Innovación Agraria de Chile (FIA), the company GECO Enterprises developed and validated “OPTIRIEGO”, an easy-to-use portable sensor prototype to establish opportunity of irrigation in fruit trees and vegetables.

The field tests were carried out with the support of tomato producers from the Pichidegua and San Vicente de Tagua Tagua area, in the O'Higgins region of Chile, who facilitated their plantations where the experimental units were established in order to compare the decision-making of the producer under their traditional criteria with the use of the OPTIRIEGO sensor.

Geco's team of professionals is made up of Dvoralai Wulfsohn; Civil Agricultural Engineer PhD; and Inés Zamora and Jaime Bahamondes, both agricultural engineers.

Agriculture is perhaps the one that will suffer the greatest problems caused by climate change, as a user of approximately four fifths of the water in the area that runs from the north to Los Ríos. As rainfall is reduced, irrigation technology, practices and the type of crops will have to respond to this reduced availability of water.

“There are various techniques and technologies to establish the water requirements of the plants. The “Scholander” type pressure pump, to date, is considered the most accurate tool since it determines the xylem potential and through this the hydric state of the crop. Stress increases as soil moisture content decreases and evaporative demand in the atmosphere increases. They are very sensitive to the variation of water and therefore exact ”, comments the executor in charge of the project, Dvor Wulfsohn.

However, they have a high cost of acquisition, maintenance and use of labor; being far from the reach of small and medium producers, who represent 85% of Chilean agriculture. Indeed, the use of irrigation water in quantity and time of application is of the utmost importance since it is a determining resource in the success of a crop.

The OPTIRIEGO project began in 2018 and ended August 31, 2021. Throughout this period, work was carried out on the design, evaluation and validation of the portable sensor prototype, capable of capturing data on temperature (room and leaf), relative humidity and PAR light reaching the blade; data with which an index of hydric stress is calculated, in this case for tomatoes as it is a widely planted spice in the region and, in addition, in Chile it is grown all year round.

Considering that the Scholander pump is very accurate, but difficult to use, it was used to calibrate the decision of the model used in OPTIRIEGO of when to water.

“To use the sensor, an easy-to-apply sampling method was established that the producer must follow in order to evaluate the corresponding plants and leaves, that is, something like asking the plant what water state it is in, for which the puts the sensor in contact with the leaf for just a few seconds, this being the one in charge of taking the data from the plant and transmitting it via bluetooth to an application installed on the producer's cell phone where the calculations of the stress index of the plants are carried out and he compares it with a critical stress value that is for each species and which in this case was made for tomatoes ”, adds Wulfsohn.

Along these lines, the executive director of FIA, Álvaro Eyzaguirre, comments that “From FIA we are very enthusiastic about this sensor since the tests showed that it could achieve 30% savings in the water applied in the crop, without affecting the yield and harvest quality of tomatoes. This is a tool that is part of Agriculture 4.0, a revolution that has gradually been soaking our sector with innovations that deliver value, especially in a context of climate change and water stress that urgently needs to be tackled ”.

On the other hand, the application shows in a friendly way the data that are being entered so that the producer knows that he is making the registration. At the end of the measurements, the sensor provides a recommendation to water or not to water, which will depend on the water strategy defined by the producer and assigned to the sensor, for this OPTIRIEGO has 3 strategies: minimize water stress, balanced, and water saving (without affecting production).