During the week of the 1st March – 5th March 2003, a survey was carried out by a small group of soil science students from the University of Sydney. The aim of the survey was to exam the difference between soil physical properties of cultivated and uncultivated (pasture) land. As it is assumed that land use generally affects the structure and the hydraulic properties of soil. The survey was conducted within the grounds of the Australian Cotton Research Institute, located in the Namoi Valley just outside the town of Narrabri. Through the use of literature and a soil description taken at the site, it was determined that the soil within the area was a black vertosol. Over the survey area 10 measurement sites were set up. Of these 5 were located in the constantly cultivated area and 5 were located in the undisturbed pasture area. At these sites measurements were obtained using a wide variety of instruments. These measurements were then taken back to the lab to be analysed to estimate properties such as moisture potential, hydraulic conductivity, water content, soil strength, fluid movement and thermal properties. The present landuse at the survey site has existed for the past 40 years; prior to this the area was devoted to pasture. It was expected that there would be an observed significant difference between the cultivated and pasture soil due to the influence of landuse and applied management.

The hydraulic properties analysis found that the overall movement of water through the cultivated and pasture were significantly different from one another, which was expected. However once compared there is no true trend present but the numbers are in the same proximity of one another.

The cultivated soil has been continually worked and compressed over years of cultivation. The combination of these processes and the high clay content would create a soil profile, which could have a slower infiltration rate and retain water. The results confirmed that infiltration through the cultivated soil was much slower than the pasture soil and reached a steady state rate.
The pasture soil, which is mainly undisturbed, has a higher ability to transmit water through the profile. This is a major requirement for the pasture soil due to the large growth of vegetation. The root systems of these plant species increase the chance of the large macro pores and cracks occurring. Cracks that are present in the soil increase the rate at which water infiltrates the soil. The results in general show that rate of infiltration in the pasture soil is faster than the cultivated soil and that the water is lost before a steady state infiltration rate is reached.

Ksat calculations are highly sensitive to sample size, flow geometry, sample collection procedures and soil physical-hydrological properties such as clay content and mineralogy and therefore have many areas for error during calculation. The Vertosol soils at the survey site are known for their shrink/swell properties, which result in cracks when dried and can lead to misleading results.

The EM38 and the Time Domain Reflectrometry (TDR) were used to measure the moisture content of the soil over the survey site. The EM38 measures the water content of the soil to a depth of 150 cm, while the TDR measures the exact time taken for water to infiltrate through the profile to a certain depth. The results agreed with the experiments above in that the water content is higher in the cultivated field than the pasture field.

Soil strength was measured by using the dynamic field penetrometer and the shear vane. The results obtained for both of the apparatus showed that there was a significant difference between the cultivated and pasture.The shear vane determined that there was a <0.0001 F probability of a statistical difference between the two sites.
While the cone penetrometer concluded that the pasture soil was harder as it showed more resistance to penetration than the cultivated soil, therefore meaning the soil is softer. This result is contributed to the fact that the pasture is more structured due to its longevity and established vegetation growth.