Impact on soil salinity and crop yield under conventional and controlled subsurface drainage system in saline Vertisols of TBP irrigation command

Abstract

Performance of conventional sub-surface drainage system (SSD) on the reclamation of waterlogged and saline soils mainly depends on proper drainage discharge to the nala through the outlets. Farmers at the tail-end of the TBP irrigation command who often face scarcity of water especially at the later part of crop growth are in practice of clogging the outlets so as to retain water in the field for the crop. This practice has lead to the inefficient SSD network in the command. Hence, controlled drainage system was planned with slight modification to the existing traditional SSD in three spacing such as 40 (2.62 ha), 50 (2.8 ha) and 60m (4.0 ha) at Agricultural Research Station, Gangavathi during 2021-22 to assess the performance of different spacing of conventional sub surface drainage system in comparison with controlled drainage on salinity and crop yield in saline rice fields. The mean soil salinity (ECe) in all the spacing under both conventional and controlled drainage system was reduced. The paddy grain yield varied from 33.0 to 48.3 vs. 38.0 to 54.2, 36.0 to 56.3 vs. 31.0 to 43.7 and 37.6 to 47.2 vs. 36.0 to 51.3 qha-1 under conventional and controlled SSD at 40, 50 and 60 m spacing respectively.