Articles
Annual evapotranspiration of pecan trees in an arid and hot zone in Mexico
Article number
1420_12
Pages
85 – 94
Language
English
Abstract
Agriculture uses about 70% of the annual available fresh water.
This resource is limiting agricultural activity in the arid and warm areas of Mexico.
The presence of perennial crops with a long growing season significantly increases the amount of water used by them, compared to annual and short-cycle ones.
Asparagus, table grapes and pecan are crops that have increased their area in recent decades in northwestern Mexico.
Pecan has had the largest increase in area and has migrated from flooded to pressurized irrigation.
However, the annual volumes used have decreased little.
To determine the atmospheric demand (ETo) and the crop evapotranspiration (ETc) of pecan trees and contribute to the efficiency of water use, a micrometeorological tower was installed in the center of an orchard of 108.0 ha in 2016 to calculate ETo.
To determine ETc a covariance system was installed in the same plot.
Additional sensors were installed in the soil to monitor moisture and soil water potential.
The results show a mean annual ETo of 1,865 mm (1,784-1,965), with a mean annual ETc of 1,409 mm (1,287-1,651), with mean annual irrigation of 1,612 mm (1,415-1,898) and mean annual rainfall of 210 mm (153-272). The average of annual water balance was +413 mm (301-506), always showing inputs are normally higher than outputs.
The water use efficiency (WUE = GPP/ET) annual average was 1.43 gC m‑2 mm‑1 (1.28-1.58), gradually improving efficiency from 2017 to 2022. The results suggest that it is possible to reduce the volume of water ha‑1 and maintain gross primary productivity (GPP). Proposing as first strategy increasing the number of driplines (four to five) to achieve the uniformity of soil moisture and as second strategy a reduction of the volume of water applied, censoring of the moisture and potential of water in the soil, the water potential in stems and stomatal conductance of pecan trees.
This resource is limiting agricultural activity in the arid and warm areas of Mexico.
The presence of perennial crops with a long growing season significantly increases the amount of water used by them, compared to annual and short-cycle ones.
Asparagus, table grapes and pecan are crops that have increased their area in recent decades in northwestern Mexico.
Pecan has had the largest increase in area and has migrated from flooded to pressurized irrigation.
However, the annual volumes used have decreased little.
To determine the atmospheric demand (ETo) and the crop evapotranspiration (ETc) of pecan trees and contribute to the efficiency of water use, a micrometeorological tower was installed in the center of an orchard of 108.0 ha in 2016 to calculate ETo.
To determine ETc a covariance system was installed in the same plot.
Additional sensors were installed in the soil to monitor moisture and soil water potential.
The results show a mean annual ETo of 1,865 mm (1,784-1,965), with a mean annual ETc of 1,409 mm (1,287-1,651), with mean annual irrigation of 1,612 mm (1,415-1,898) and mean annual rainfall of 210 mm (153-272). The average of annual water balance was +413 mm (301-506), always showing inputs are normally higher than outputs.
The water use efficiency (WUE = GPP/ET) annual average was 1.43 gC m‑2 mm‑1 (1.28-1.58), gradually improving efficiency from 2017 to 2022. The results suggest that it is possible to reduce the volume of water ha‑1 and maintain gross primary productivity (GPP). Proposing as first strategy increasing the number of driplines (four to five) to achieve the uniformity of soil moisture and as second strategy a reduction of the volume of water applied, censoring of the moisture and potential of water in the soil, the water potential in stems and stomatal conductance of pecan trees.
Publication
Authors
J.C. Rodríguez, S. Er-Raki, F. Cruz-Bautista, A. Meddich, C. Lizárraga-Celaya, A.E. Castellaños-Villegas, A. Ochoa-Meza
Keywords
eddy covariance, crop evapotranspiration, reference evapotranspiration, irrigation, arid lands
Groups involved
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