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| Authors: | C. Mirábile, J. Morábito, G. Fasciolo, H. Loustaunau |
Abstract:
This paper seeks to establish and analyze the dynamics of salts in the soil with crops irrigated with surge-flow and surface irrigation, and to determine whether the soil’s final electrical conductivity (F EC) is associated or not to the irrigation method.
In the case of surge-flow irrigation, water is applied intermittently.
The farms selected use both systems to irrigate the same crops (grapes, olive trees and vegetables) and are located in the cultivated areas of the Mendoza and Lower Tunuyán rivers.
The methodology consisted in selecting two furrows at random for each type of irrigation (surge-flow, surface), dividing them into three sectors (head, middle, tail), and taking soil samples from two layers (0-40 and 40-80 cm). The soil samples were taken at the beginning and end of each crop cycle.
Electrical conductivity (EC) was determined at the laboratory using the saturated paste method and measured in micromhos/cm at 25ºC.
Tables have been prepared that show salt content variations with each type of irrigation for the whole profile and for each of the sampled layers.
A multiple regression model was applied on all the data obtained (384 samples). Final salinity (F EC) is a function of initial salinity (I EC) and of the type of irrigation (surge-flow, surface).
The best-fitting function is linear.
The estimation of 1 (initial salinity) is significantly different from 0 (zero) (P = 0.0001), whereas 2 (type of irrigation) is not (P = 0.376). This is taken to mean that the soil’s F EC is not related to the type of irrigation.
As 1 is significantly smaller than 1, it is considered that both types of irrigation produce desalination.
The percent difference between F EC and I EC is not associated with the type of irrigation at the furrow’s head, middle or tail.
The changes in EC are not homogeneous within the farm.
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