During these months, temperatures begin to drop and the different crops need less and less irrigation than in the summer. In fact, in cherry production it is recommended not to extend it beyond March 31, except in soils with little moisture retention, when the end of the season is postponed until approximately April 10. Therefore, this is a good time to carry out a more exhaustive check of the irrigation equipment and take care of the most important maintenance.
A farmer could save between 15 and 40% of water without decreasing yields, considering average irrigation efficiency.
For Kurt Neuling, manager of the Sustainable Fruit Growing Program of the Valparaíso Region, of Corfo, “maintaining, operating and programming irrigation is one of the paths towards sustainability, combined with collaborative work,” entity that, together with the National Irrigation Commission and INIA La Cruz, joined forces to train field managers and contribute to alleviating the effects of the crisis, giving priority to the delivery of knowledge. Two events were held in April and May 2022, providing a necessary opportunity for fruit growers to update their knowledge.
Specialists Rodrigo Candia, agricultural engineer at INIA La Cruz, and Raúl Ferreyra, private consultant, addressed these issues in the midst of the difficult situation facing the country, and specifically the Valparaíso region, as a result of water shortages.
The maintenance and operation of irrigation equipment is a key practice in the efficient management and use of intra-farm irrigation water. Operating and maintaining the equipment properly allows the system to keep functioning at its designed optimum for longer. In a climate change scenario, the specialist assures that this water crisis also brings with it an energy crisis. Experts assure, “Not only will this generate water inefficiency, but also energy inefficiency that will directly impact the producer's pocket, because not only will they spend more money on electricity, but they will also use more resources in the operation.”
Rodrigo Candia Antich, researcher at the Agricultural Research Institute, INIA La Cruz, says that proper use of the irrigation system and all its components is essential. “If proper and timely maintenance is carried out on the different components of an irrigation system, the theoretical application efficiency can be maintained, which can reach 90%, and only 10% of the water we apply will be lost.”. In other words, he said, “By carrying out maintenance, the irrigation system remains operating in its optimal design condition, reducing water losses. However, if this maintenance is not carried out, the equipment starts to function poorly and we can drop to 60%.”
Otherwise, the expert says, “The pump starts to work out of order, leaks begin and a series of other problems get worse as many years go by without performing maintenance on the equipment, mainly the pump.”. It is noted that in the case of pumps that do not undergo periodic maintenance, after 5 or 6 years of use, very extensive maintenance must be carried out, even having to replace their components or even the entire pump. “The cost of these maintenance tasks can be up to six times more expensive when they are not carried out on time. Therefore, we can have a high investment team. If we are responsible with maintenance, we are more efficient in the production unit.”
He points out that the most important maintenance takes place during these months when the irrigation season begins to decrease. Among these, it is important to remove and maintain the pump, empty the accumulators, clean the sand traps and decanters, mainly of sediments that have accumulated during the season. Check the pressure and flow parameters, the electrical part of the irrigation system, make sure there are no sulfation problems, that the connections are well made, that there are no cable cuts. In the case of quartz filters, remove the sand and clean it with phosphoric or nitric acid to avoid cementation inside the filter that could affect its operation.
Raúl Ferreyra, irrigation specialist, provided some options to be efficient in the use of water and reach productive potentials without affecting yield. Among these aspects, he highlighted the need to make surface adjustments based on the amount of water available, as well as reducing evaporation and, depending on each requirement, carrying out more spaced irrigations without affecting yield and depending on the phenological state of the plant.
The specialist pointed out that reducing the amount of water in some phenological periods without affecting the yield and the plant is possible, but for specific situations and during a limited season. “It is not useful for scheduling irrigation, since in the long run we will have a decrease in the water reserve.”
He also explained that the use of mulch reduces evaporation losses while frequent irrigation has higher evaporation losses. 26% of water can be saved through evaporation under suitable conditions. “Water as far apart as possible. To the extent that we can water at a distance, we will reduce evaporation losses.”
He also pointed out that if you want to reduce evaporation, you should check that the roots are deep. “The development of the root system is essential and leads to greater water requirements. Evaporation losses are higher in walnut trees and can be reduced by 10%.”
Given the current conditions, the ideal is to go towards drip irrigation. He said that in Petorca many avocado orchards with micro-sprinkler systems were changed to drip irrigation since, among other advantages, it allows the use of mulch. “The changes are significant, the use of mulch, preferably white, helps prevent water loss through evaporation.” He commented that there are areas where in the middle of summer the mulch The temperature of the soil increased. For this reason, he said, “You have to be careful with soil temperatures. The roots can benefit or be harmed. Mulch is not suitable in high temperature areas.”
This training was part of the INIA/CNR agreement “Increasing water use productivity by strengthening training, outreach, and technology transfer to beneficiaries of irrigation projects.”
