
%0 Journal Article
%A Rasiah, V. 
%T Assessing tillage- and cropping-induced changes in relative conductivity
%J Soil Research
%D 1998/08/20
%V 36
%N 5
%P 799-808
%K porosity, pore continuity, fractal dimension.
%R https://doi.org/10.1071/S98007
%U https://www.publish.csiro.au/paper/S98007 
%X Although changes in relative hydraulic conductivity(Krc) in the surface soil layer can have significantimpact on transport of water and solutes below this layer, experimentaldetermination of Krc is laborious and expensive. In thisstudy, a simple theoretical equation has been used to compute near-surfaceKrc and assess its sensitivity to tillage- andcropping-induced near-surface changes in soil porosity (.epsi;), porecontinuity (PC), and soil water content (&thgr;). The data were collected in1994 from a cropping and tillage system experiment established in 1988 on asilt loam soil. The tillage treatments were conventional and no-till. Thecropping treatments were continuous corn (Zea maize L.)under conventional cultivation (CT corn), corn following forages(alfalfa,Medicago sativa L.; and bromegrass,Bromus inermis L.) under conventional and no-till (NTcorn) practices, and continuous no-till corn. Soil bulk density (r ) and inthe near surface (depth, 0-2 &#183;5 cm) soil layer were measured in lateJuly 1994 subsequent to changes in tillage and cropping practices in May 1994.Only tillage differences had significant influence on &rho;, &thgr;, fractaldimension (D), PC, and Krc of the near-surface soillayer. A switch from no-till forages to CT corn resulted in increases in andD, and decreases in &rho; , &thgr;, and Krc. Theintroduction of NT corn into forage-terminated plots did not producesignificant changes in the above properties compared with continuous NT corn(7 years old), which was characterised by smaller values of and PC, and high&thgr; and Krc. Water content, , and PC accounted for96% of the variability in Krc. The results showedthat the near-surface changes in Krc can be predictedwith high accuracy using the data on only &rho; and &thgr; which are easy togather. 
