Characterizing Salt-Affected Soils of Songnen Plain Using Saturated Paste and 1:5 Soil-to-Water Extraction Methods

Abstract

In the Songnen Plain, Northeast China, chemical parameters of salt-affected soils were previously obtained from 1:5 soil-to-water (1:5) extracts so that there is no information available for soil salinity and sodicity from the saturated paste (SP) extracts. The work reported here characterized soil salinity and sodicity of SP extracts and compared salinity and sodicity measurements using SP and 1:5 extraction methods from 121 soil samples from various sites of salt-affected soil areas in the Songnen Plain. Electrical conductivity (EC), major cations Na + , K + , Mg 2+ , Ca 2+ , sodium adsorption ratio (SAR), and pH were determined and analyzed using SP extracts and 1:5 extracts.The sodium ion was the predominant cation so that Na + concentration was close to total cation concentration (TCC). The SAR in the 121 samples was remarkably high; 22 soils had a SAR > 1000 mmol c L −1 1/2 with a maximum SAR value of 4042.57 mmol c L −1 1/2 for SP extract. The SAR was highly correlated with EC r 2 > 0 86 P < 0 0001 . The salt-affected soils are predominantly saline-sodic based on the classification of the USDA (1954). Through a regression analysis, total cation concentration was strongly related to EC with slopes of 10.3 and 9.8 without y intercept in SP and 1:5 extracts, respectively.Significant relationships r 2 > 0 81 P < 0 0001 existed between EC, Na + , and SAR in SP and 1:5 extracts. However, K + , Ca 2+ , and Mg 2+ of SP extracts was not related to those of 1:5 extracts.

Germination and growth of Puccinellia tenuiflora in saline-sodic soil under drip irrigation

“…The average total soluble salt in the surface soil has a range of 0.5-1.0% with sodium accounting for more than 80% of the total dissolved cation concentration, and a pH range of 8.5-10.5 with exchangeable sodium percentage (ESP) ranging from 70 to 80% (Li et al, 2006). The average sodium adsorption ratio (SAR 1 ) is more than 30 (mmol L −1 ) 1/2 (Chi and Wang, 2010). The structure of this soil is very poor, and the permeability is very low: hydraulic conductivity at saturation is only 0.02-0.22 mm d −1 , which is in the low water-permeability range (Chi and Wang, 2010).…”

“…The average sodium adsorption ratio (SAR 1 ) is more than 30 (mmol L −1 ) 1/2 (Chi and Wang, 2010). The structure of this soil is very poor, and the permeability is very low: hydraulic conductivity at saturation is only 0.02-0.22 mm d −1 , which is in the low water-permeability range (Chi and Wang, 2010). The rate of infiltration decreases quickly 10 min after irrigation, and by about 15 min after irrigation the water essentially ceases infiltrating .…”

Influence of Irrigation Water Discharge Frequency on Soil Salt Removal and Rice Yield in a Semi-Arid and Saline-Sodic Area

“…The first approach is difficult to control, whereas the irrigation and discharge schedule can affect at least the last two of the above three approaches. In fact, due to poor permeability of saline-sodic soil on the Songnen Plain [22,23], the salt losses may mainly depend on surface runoff rather than leaching. However, while effects of different irrigation schedules on soil salt and rice yield were widely reported [24][25][26][27], few field studies exist on the effect of discharge frequency on salt removal of saline-sodic soils under rice culture, a knowledge that is crucial for large-scale rice paddy management on China's Songnen Plain.…”

Robust Soil Quality Index for Tropical Soils Influenced by Agricultural Activities

“…The pH of each sample unit tested was determined by using a potentiometer in both the 1:2 soil to water mixture and the saturated paste methods [15]. Electrical conductivity (EC) was carried out with a multiparameter (Toledo, Seven Excellence) based on methodology proposed by Chi & Wang [15].…”