“…Others have reported on the influence of relief curve lines on crop yields (Thwaites and Slater, 2000;Manning et al, 2001;Zebarth et al, 2002;Kravchenko and Bullock, 2002;Norton et al, 2003;Si and Farrell, 2004;Razaei and Gilkes, 2005;Martín et al, 2005;Zhang and Zhang, 2005;Terra et al, 2006;Rees et al, 2007). In general, independent of the use of curvature models, the studies that determine the soil quality in orange cultures present several chemical, physical, and hydrologic attributes.…”