Soil hydraulic conductivily measurement on a sloping field

Abstract

A field methodology is presented for the measurement of the soil hydraulic conductivity in a sloping field, minimizing the leveling soil movement before water pounding and redistribution. The assurance of vertical flow only is performed through soil water potential isolines. The hydraulic conductivity was determined by the instantaneous profile method. Results for the nine neutron probe access tubes indicate that one single K(theta) relation is sufficient to represent the experimental site.

Water balance of a sugarcane crop: quantitative and qualitative aspects of its measurement

“…After this these became very large, assuming values as high as 80 mm d -1 , due to the high rainfall period and to the low storage capacity of the profile. Although high, these values are 24 times lower than K o (1,947 mm d -1 ), the saturated hydraulic conductivity of this soil at the same depth (Timm et al, 2000). Cintra et al (2000) also measured values of Q L this order of magnitude.…”

“…On the other hand, as mentioned in the introduction, Govindaraju et al (1992) state that K(θ) determinations based on Richards equation, lead to complications in their application. The unit gradient approximation used by Libardi et al (1980), adopted by Timm et al (2000) and strongly criticized by Reichardt (1993) is another problem to be taken in account. In order to verify if there are differences of soil water storage among treatments, ANOVA was performed using dates as replicates.…”

“…The hydraulic conductivity function K(θ), for z = L, was obtained from measured data collected in an area of 18 m 2 at the lower end of the experimental site, using the instantaneous profile method (Hillel et al, 1972 andLibardi et al, 1980), adapting the methodology to a sloping field. Soil leveling was minimized, flooding soil surface in three adjacent platforms of 1.4 x 4.0 m, and assuring only vertical flow (Timm et al, 2000).…”