Electrical Electrical conductivity is used to An EC test should be Conductivity (salinity) infer the salinity of the soil and its carried out on a soil sample potential impact on plant growth. from each horizon from The EC. of the saturated extract each test pit excavated (ECe) is calculated by first during the soil assessment. measuring the electrical conductivity This test can be carried out of 1:5 soil in water suspensions and using a hand held meter, or using appropriate multiplier factors in a soil testing laboratory. to convert EC (1:5) to ECe. It can be measured with a hand-held EC meter. Moderate (range) to high (range) salinity typically inhibits or limits growth of many plant species, thereby reducing plant uptake of nutrients and increasing the risk of erosion on the land application area. Sodicity The proportion of sodium on the ESP should be carried out (exchangeable cation exchange sites reported as a if there is any evidence of sodium percentage percentage of exchangeable dispersion, slaking, or cations. Levels above 6% may structural decline in the cause soil structural problems and soils on or near the reduced permeability. potential land application area/s. This test is carried out in a soil testing laboratory. Phosphorus Phosphorus adsorption (P-sorption) Sites where a nutrient adsorption (mg/kg) is the capacity of soils to or balance is to be carried out, ‘take up’ immobilise phosphorus, which is e.g. sites where risks of present in various forms in phosphorus export should wastewater and treated effluent. be minimised, or where the soil is intended to be used Sandy soils typically have low as a phosphorus removal capacity and do not mechanism. necessarily need to be tested if a conservatively low (100 mg/kg) There are a range of sorption rate is assumed for any sorption tests, carried out in nutrient balances undertaken. Clay a soil testing laboratory. soils and soils high in iron and/or aluminium often have high sorption (up to 450 mg/kg and greater).
Electrical Conductivity (salinity) Electrical conductivity is used to infer the salinity of the soil and its potential impact on plant growth. The EC. of the saturated extract (ECe) is calculated by first measuring the electrical conductivity of 1:5 soil in water suspensions and using appropriate multiplier factors to convert EC (1:5) to ECe. It can be measured with a hand-held EC meter. Moderate (range) to high (range) salinity typically inhibits or limits growth of many plant species, thereby reducing plant uptake of nutrients and increasing the risk of erosion on the land application area. An EC test should be carried out on a soil sample from each horizon from each test pit excavated during the soil assessment. This test can be carried out using a hand held meter, or in a soil testing laboratory. Sodicity (exchangeable sodium percentage The proportion of sodium on the cation exchange sites reported as a percentage of exchangeable cations. Levels above 6% may cause soil structural problems and reduced permeability. ESP should be carried out if there is any evidence of dispersion, slaking, or structural decline in the soils on or near the potential land application area/s. This test is carried out in a soil testing laboratory. Phosphorus adsorption (mg/kg) Phosphorus adsorption (P-sorption) is the capacity of soils to ‘take up’ or immobilise phosphorus, which is present in various forms in wastewater and treated effluent. Sandy soils typically have low capacity and do not necessarily need to be tested if a conservatively low (100 mg/kg) rate is assumed for any nutrient balances undertaken. Clay soils and soils high in iron and/or aluminium often have high (up to 450 mg/kg and greater). Sites where a nutrient balance is to be carried out, e.g. sites where risks of phosphorus export should be minimised, or where the soil is intended to be used as a phosphorus removal mechanism. There are a range of tests, carried out in a soil testing laboratory. sorption sorption sorption
guidelines-land-capability-assessment-onsite-wastewater-management.docx