From inside the river: cleaner water for crops

From left to right: Professors Carlos Arturo Madera, Luis Darío Sánchez, Édgar Quiroga, Diego Fernando Manotas, Eduar Aguirre y Andrés Echeverri. Credit: Faculty of Engineering Communications Office.

Dedicated to growing an increasingly variety of crop foods, the municipalities of Roldanillo, La Unión and Toro face the consequences of pollution in the Cauca River, whose water is used to irrigate their crops. A group formed by schools of the Engineering Faculty of the Universidad del Valle aims to improve their production conditions, through a complex project in which they will participate in a transversal way. The aim is to increase the quality of water and quantity of production in this sector of Valle del Cauca, as well as their possibilities of integrating into larger supply chains. 

The project and area to be intervened

In the occasion of the announcement made by the Ministry of Science, Technology and Innovation on November 11, 2022, whose purpose was to form a list of projects that contribute to solving challenges related to food activities, the school of Natural Resources and Environmental Engineering, Chemical Engineering, Industrial Engineering and the Institute for Research and Development in Water Supply, Environmental Sanitation and Water Resource Conservation (CINARA), together with Innovagric and the NGO called “ScienteLab”, joined forces and presented the project “Strengthening of small producers for the management of water quality in food production in the Land Adaptation District of the municipalities of Roldanillo, La Unión and Toro (RUT), in Valle del Cauca”, whose main beneficiary will be the Association of Users of the Land Adaptation District of the municipalities of Roldanillo, La Unión and Toro, ASORUT. 

This association is in the flat area of this municipalities and works in an area of approximately 10,200 hectares, bordering the Cauca River in three of its four cardinal points. With State infrastructure, ASORUT has overseen managing the irrigation system since 1989. The main crops grown in this area include corn, guava, grapes and, in greater growth in recent years, sugar cane. 

According to FAO estimates, 86.4% of the 1975 farms of this district are used by small farmers, of which the majority are in Roldanillo, with 1240, followed by La Unión, with 674, and Toro, with 64. It should be added that, based on DANE reports in 2022, the Multidimensional Puberty Measures (MPM) is higher in the rural areas than the municipal capitals. These factors, coupled with ASORUT’s experience in the field and the potential as a laboratory that can practice on a larger scale, made the district an ideal place to carry out this project. 

This project purposes the need to intervene the conditions of the irrigation system applied in Valle del Cauca, the main activity related to the crops growing in the area, based on a clear premise: if water quality improves, it is likely to increase production capacity and opportunities to access new markets, both regionally and national. Three fundamental objectives were conceived: 

1) Implement sustainable technological solutions to improve irrigation water quality in the RUT district to meet export quality standards, 2) Implement a sustainable technological platform to facilitate irrigation scheduling decisions at the farm levels and efficient water use, and 3) Develop a training process through dialogue of knowledge and experimental learning to close knowledge gaps in water quality improvement and irrigation scheduling. 

To respond to these purposes -and aware that it requires parallel work from different fields of knowledge-, the project proposes a synergy that covers as many fronts as possible, as we will see below. 

Riverbed Filtration: the bet for cleaner water 

Th focus of the project will be water, improving its quality. “Basically, what we are going to seek is to improve the management of the quality and quantity of water that has to do with food production”, explains Professor Luis Sánchez, coordinator of CINARA. According to him, the path taken by the Cauca River, when it reaches the irrigation system, brings it with waste and toxins from wastewater discharged from cities such as Cali, whose impact on the river in terms of contamination alone is approximately 40 to 50%. 

These contamination levels have become a problem to be considered, since there is considerable food production in the area in question, which transfers into a barrier to exporting their products and entering larger chains, due to phytosanitary controls. 

“For this reason, we are going to empathize with the objective of improving water quality, considering a technology that we have studied here: riverbed filtration”, says Professor Sánchez. 

Riverbed filtration is carried out through a method called “vertical drilling”. It is a system that captures water through a natural filtration process: the river is channeled to flow subway into the grown, on its way to a well, from which is then extracted. The path taken by the water produces a natural filtration phenomenon, as it travels through the porous strata located internally. In the end, the water obtained after this process is better, both from a microbiological and physicochemical point of view. 

To do this, the team in charge of this task will have to study in the area, to distinguish the key points of internal water catchment, and then to establish the place where the structure that will facilitate the process will have to be erected. “The system will be made, and after the system is made it will be taken to a king of irrigation plot, where we will test what kind of crops will be planted, how it will be irrigated, and we will look at what happens to the irrigation with the water quality variable, which we hope will be much better in that system than in the one they currently have”, asserts Sánchez. 

The intricates involved in a project of this type do not end here. While the riverbed filtration system is being put into operation, research groups from the other academic units involved in the project are doing their work, so that what results from these efforts does not remain a happy event of a few weeks, with no future benefits for the community. 

Land Adaptation District of the municipalities of Roldanillo, La Unión and Toro (RUT), in Valle del Cauca. Credit: Professor Andrés Echeverri (REGAR).

 Smart irrigation and future uses

One of the objectives of this project is to generate an irrigation system for the district that allows producers to have the ideal technological tools so that their crops have the best care conditions. At the forefront of this purpose will be the Comprehensive Water Resource Management Research Group for Agricultural Development and Food Security through Irrigated Agriculture, who will be able to put into practice an intelligent irrigation technology developed by Professor Edwin Erazo during his doctoral research, and which was used in Hass avocado crops. 

This irrigation system is made up of sensors, satellite images and other artificial intelligence techniques, and is designed as a tool for producers to know when they should irrigate their crops and in what proportions. 

 “What advantage does the tool have? It is too simple: it is a web tool. The version that we have for assembly is open. And it works for multiple platforms. For a desktop computer, but also for farmers who see it from their cell phones,” says Professor Erazo, adding that the system can be configured in a useful way for other crops in the district. 

This intelligent irrigation system will then seek to guarantee that crops receive the amount of water necessary for better production. But it will not be the only action to qualify the quality and quantity of water to be used in this irrigation system. This project seeks for producers to see in this initiative a way to learn to be sustainable over time, from an economic perspective. 

This will be led by Professor Diego Manotas, from the School of Industrial Engineering. The role of this school in the project will be, as in previous cases, transversal, but it will be seen especially in the points related to the financial analysis of the activities. 

Their work will be to observe the business model within ASORUT: analyze its cost structure, determine whether it is integrated into a larger production chain and whether sales are being made. Then, as the project develops, it is hoped to analyze the impact that the new conditions will have on them. The goal is to increase production and improve product quality. 

Professor Manotas’s Research Group will also take into consideration the second general objective of the project, which professor Edwin Erazo’s Research Group will be leading. In this aspect, the idea will be to promote analysis to enable a pricing of the service, which will allow both the Association and the small and medium farmers in the area to implement systems and business models so that “this genuinely goes from being a prototype of a platform to a business model an a service that can be charged for, so that it is sustainable over time”, according to Professor Manotas. 

Care for the surroundings communities

The transdisciplinary nature of this project even considers the effects on neighboring communities, so that the impact of this pilot project does not affect the conditions of municipalities near the irrigation area. Professor Juan Rueda, from the HIDROMAR research group, EIDENAR, tells us what his role will be at this point. His group will oversee monitoring the behavior of the water at each stage. Under his magnifying glass will be the physico-chimique quality of the liquid,e.g oxygen, turbidity, nutrients, among others. 

This analysis will be carried out during the entire duration of the project and will consider the climatic seasons and other factors that occur during this period. Its task will be to estimate what will happen in the future, based on the data collected, and try to verify that the water quality is subject to the national and international standards. 

“We have to go to the fields to take information, take water samples to characterize its current quality, take topographic and bathymetric information of the area, take photographs, flow information, hydraulic information, among others. And once this information is available, it is analyzed and characterized to implement a numerical hydrodynamic and water quality model to analyze the current and future dynamics of the parameters through the simulation of various scenarios. Trying to represent what you see now and what it would look like when modifications or new downloads arrive is important for the sustainability of the project or pilot," are his words.

But this is not all. The professor indicates, in agreement with his colleagues from other units, that a productive unit activity such as this must be sustainable, and for that, the surrounding communities must also be considered, to avoid indirect damages. Their studies will also be aimed at showing the quality of the water that comes out of the irrigation system, once it is used by the farmers. “What we are interested in is to determine, from what they return to the river after their activities, how it will modify the river and the water that follows downstream. What is acceptable is that the water reaches the communities downstream with the same conditions as it is reaching them. That is acceptable. Ideally, it should reach them in better conditions”, he says. 

Prospects

This project is expected to begin this year, after which a community relations phase will follow. Professor Andrés Echeverri, from the EIDENAR’s School and who has been leading the project, summarizes what is to come as follows: “the socialization phase is with the farmers, to tell them, to involve them in the development of the project. Then comes a phase of information generation, field work: water simple, soil sample, exploration for the filtration pit. A series of basic studies, where the process of social appropriation of knowledge also begins”. This last objective, which will ensure that the knowledge of these academic units remains permanently in the hands of the community, is part of the desire that this project has for the future, and for which the NGO “ScienteLab” will be key. 

For Professor Eduar Aguirre, professor at Regionalization System, based Yumbo, and Quantitative Finance Research Group member, this is also fundamental. “That is the third objective of this project: the transfer of knowledge so that they can continue. So that they can internalize that, methodologically, if they are organized and have the technology, they can carry out the projects”. He also adds that, although the impact on the community can be seen with the developments of the pilots, leaving then the knowledge and technology transfer becomes something much more important, in the long term. 

“This project has many advantages. The number one advantage is that what we do works. We’re going to leave it working. It stays with the beneficiary. And, if the results are very promising, it can be scaled up and taken to another dimension”, concludes Professor Luis Darío Sánchez. 

 

This project will be financed by General Royalty System’s resources. It’s integrated by the professors  Andrés Echeverri, Juan Gabriel Rueda, Edwin Erazo, Carlos Madera and José Luis García, from the Natural Resources and Environmental Engineering School; Fiderman Machuca, from the Chemical Engineering School; Eduar Aguirre (Yumbo) y Diego Fernando Manotas, from the Industrial Engineering School; Édgar Quiroga y Luis Darío Sánchez, from the CINARA Institute; and César García, from the Civil and Geomatic Engineering School.

If interested in being in touch with the researchers or any further information about the scientific article published, please write the Faculty of Engineering Communications Office: comunicaingenieria@correounivalle.edu.co