Analysis of the Surface Soil EC Dynamics and the Economic Benefit under the Subsurface Drainage System

Abstract

Subsurface drainage was known as an effective method to solve salinity problems, in this paper, two different subsurface drainage systems were designed to study how the system affect the surface soil EC(electric conductivity), besides, the economic benefits of the system were evaluated. Results showed that: under the drainage system, the surface soil EC was in a trend of fluctuant reduction, the desalination ratio of T1.1, T1.2, T2.1, T2.2 and CK was 13.5%, 11.2%, 14.8%, 12.6%, and 6.0% respectively; the surface soil EC would present an rising trend in an irrigation cycle on account of the evaporation and the groundwater level, compared with CK, the drainage treatments could better suppress the soil resalination; the calculation results of economic indexes proved that both T1 and T2 could gain favorable economic benefits, and T2 was preferable with higher EIRR (16.4%), ENPV (4536$/hm2) and EBCR (1.48). The results also suggest that the subsurface drainage system was practicable from ecological and economic angle.