BLAINSKI, Everton.; GUIMARÃES, Rachel M. L.; AZEVEDO, Tedson L. F.; GONÇALVES, Antônio C. A.; BERTONHA, Altair.; FOLEGATTI, Marcos V.
Résumé:
Soil moisture can be measured by some techniques. Among of them, the TDR (Time
Domain Reflectometry) usually shows good results. Hydrogels can modify soil properties,
contributing to improve soil water storage capacity, that is why they are been used on the last years on
agriculture. However, recent studies showed that soil properties can affected TDR readings. Four
substract composed by sand and different concentrations of hydrogel were mounted to evaluated its
effects on readings of TDR. To compare TDR readings with substract moisture (q), it was
gravimetrically measure. The results of moisture readings were submitted on statistical analysis. Could
be observed that different concentration of hydrogel caused little influence on the readings of moisture
using TDR. The models that related q with dielectric constant (Ka) showed high values of
determination coefficient (r2 > 0.993), for all concentrations. Statistical analysis of fitted models
parameters show significant differences among them. But, in practical view point we can accept that
these differences are little enough to be negligible in relation to TDR reading variations. These
variations are caused by some variables like: probe characteristics, substract-rods contact and others
that affect TDR reading.
