Evaluation of a micro-sprinkler irrigation system at an apple farm in the central valley of Chile.

摘要

A micro-sprinkler irrigation system composed of six independent pumping systems and 18 irrigation subunits, under different soil characteristics and apple orchard cultivars in a 100 ha apple farm, was evaluated. The evaluation was done using the Christiansen Uniformity Coefficient (CUC), the Efficiency of Low Quarter (ELQ_25%) and Total Efficiency Distribution (TED). In addition, an analysis of the pressure at different positions in the systems, from the exit of the control head to the end of the lateral in the sub-unit, the effect of pipe size of distribution system in the energy cost and time of irrigation and volume applied was performed. The CUC and ELQ_25% were 84 and 79%, respectively, whereas the average TED was 23%, due to the excess of water applied, of up to 100% in the irrigation times in some sub-units. However, the 5 day irrigation frequency used was adequate on the basis of soil, climate, and orchard characteristics. The operation efficiency of the pumping systems took values from 33 to 87%, an increase resulting from changes in the discharge required by every subunit in the micro-sprinkler systems. In addition, a large decrease of pressure from the control head to the last laterals in the sub-unit, due to the small pipe diameters, was found. If changes in diameters were made in the diameters of principals, manifold and auxiliary and the irrigation times applied were the required ones, it would be possible to reduce the costs of operation by up to 51%.