Soil Chemistry Overview

This data reflects both the natural elemental composition at the site and the historical influence of nutrient management. Some soil properties such as organic carbon indicate overall soil health, whilst other such as Sodicity, Aluminium and salinity may indicate constraints to root growth and soil water extraction. Comparison between sites of the same soil type will help better understand the difference between these two influencing factors. High or low levels of some nutrients may indicate that some changes in nutrient management may be necessary and we suggest that you contact your local agronomist for their recommendations.

Soil pH is ideal being slightly acid to neutral throughout the soil profile. The cation exchange capacity at 7.19 -7.74 meq/100g in the A1, 2A1 and 2B1 horizons is moderate, and thus this soil has moderate to good ability to hold and supply nutrients. The organic carbon content is high throughout the profile which is likely to be due to its wet nature and past burial. However, it is noted the A1 horizon has lower organic carbon at 2.43 % than the buried 2A1 horizon at 3.37 % which indicates that current management practices may not be supplying sufficient residues to maintain surface soil carbon levels. The soil profile is noted to be highly saline especially the 2A1 and 2B1 horizons, this indicates that wetness in this region is caused by a saline groundwater coming to near the soil surface, in which salts are partly washed out of the surface soil by irrigation and rainfall, but accumulate in the lower A horizon and upper B horizon. The soil profile is also noted to be sodic as the 2A1, 2B1 and 2B2 horizons all have ESP (exchangeable sodium ratios) over 5. Potassium, phosphorous and sulphur are all noted to be very high, with potassium and sulphur accumulation in the 2A1 and 2B1 horizons, which indicates excess potassium fertilizer is being transported through the soil profile.