The Comparison of Electrical Conductivity for Soil Solutions Extracted in Field Capacity and Saturation-Paste
2010
Lee, Y.J., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea | Lee, J.S., National Academy of Agricultural Science, RDA, Suwon, Republic of Korea | Yang, J.E., Kangwon National University, Chuncheon, Republic of Korea
Estimating the electrical conductivity of the saturation-paste (SP) is a common method to assess soil salinity. To assess soil salinity realistically, it is important to extract soil solution under field capacity. However, few studies on salinity assessment have been conducted for soil solution extracted under field capacity (-33 kPa; FC) moisture condition due to difficulty in soil solution extraction. This study was conducted to evaluate whether saturation-paste can represent field condition. Soil solutions were extracted from 22 soils in the plastic film house (PFH) and 18 soils in the reclaimed land (RL) at saturation and field capacity moisture conditions. Those were analyzed for pH, EC, cations (K+, Ca²+, Mg²+, Na+) and anions (Cl-, NO₃-, PO₄³-, SO₄²-). Both cations and anions of soil solution extracted from FC showed high correlations with ions extracted from SP in the PFH and the RL, except for NO₃-, PO₄³- in the RL. Results of the t-test, the ECe and EC∧FC were not significant at significance level 0.05. The slopes of the equations between EC∧FC and ECe at more than sand 50% soils were higher than less than sand 50% soils, and differences of saturation percentage between SP and FC showed larger as increasing sand percentage. EC was related to soil water retention by soil texture. To determine the EC, soil texture and other soil properties which effect the soil moisture should be considered.
显示更多 [+] 显示较少 [-]