Feasibility of Controlled Drainage in Saline Vertisols of TBP Command Area of Karnataka, India

Abstract

Subsurface drainage (SSD) improves crop productivity in canal command areas suffering from waterlogging and salinity problems. However, excessive drainage of paddy fields under conventional SSD is known to cause irrigation water shortage during critical growth stages of rice and also results in excessive leaching of nitrogenous fertilizers particularly at the tail end of the irrigation command. To overcome these problems farmers of the Tungabhadra Project (TBP) irrigation command used to block the outlets of lateral drains of the SSD system. In order to provide a lasting solution to this problem through a controlled drainage approach, a comparative field study was conducted on clay loam soil at the Agricultural Research Station (ARS), Gangavathi, over four seasons. In general, there was a reduction in drain discharge depth of 64% in the case of controlled drainage over conventional SSD, with an average irrigation water saving of about 17%. Average nitrogen loss was also reduced by 50.4% compared to conventional drainage. Paddy grain yield improvement was slightly higher (from 3.84 to 5.14 t ha−1) for conventional compared to controlled conditions (3.76–4.83 t ha−1). © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd.

Economic feasibility of subsurface drainage (SSD) to control waterlogging and soil salinity under different scenarios in the Tungabhadra project command, Karnataka, India

“…The dimensions of the manhole/inspection chamber were 2 × 2 ×1.5 m (6 m³), and those of the guard wall were 2 × 0.6 ×1.8 m (2.16 m³). The inspection chamber was interconnected through a trench of collector drains and finally connected to the Nala /stream through an outlet under gravity flow (Karegoudar et al, 2019).…”

“…The economics of these SSD systems were carried out in terms of total returns, cost of cultivation, net returns, net present value (NPV), benefit–cost ratio (BCR), internal rate of return (IRR) and payback period (Karegoudar et al, 2019; Raju et al, 2016) after the implementation of the drainage system over 30 years of life.…”

“…A subsurface drainage (SSD) system has been accepted as an efficient solution to control waterlogging and soil salinity. Earlier studies on SSD systems under the Indo-Dutch network project (Indo-Dutch Network Project (IDNP, 2002a) in the Upper Krishna command (UKP) area, Bheemarayanagudi, Karnataka, and the AICRP on Management of Salt Affected Soils and Use of Saline Water in Agriculture, Gangavathi, have shown that SSD systems with 50 m lateral spacing and placed at 1 m depth were effective in reclaiming waterlogged saline soils both in the UKP and TBP commands (Karegoudar et al, 2019). However, the question remains whether SSD would be successful in all three conditions (i.e.…”

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“…Man Singh et al (2002) [9] reported the highest (44.7 dS m -1 ) and lowest (3.86 dS m -1 ) mean salinity of drainage effluent at 35 and 15 m drain spacing areas which were in initial stage of reclamation. Whereas, Karegoudar et al (2019) [6] reported that the drain water salinity at 50 m drain spacing varied from [10] wherein the mean EC of majority of water samples of natural streams of LBMC in TBP command area were under category of C3 (EC 0.75 to 2.25 dS m -1 ) which indicate high salinity hazard and hence not feasible for irrigation. The canal water which passes through waterlogged saline soil and discharged into the natural stream (nala) would be of poor quality as it carries salts present in the soil profile.…”

Effects of modelling studies on controlled drainage in agricultural land on reduction of outflow and nitrate losses–a meta-analysis

“…DWM is gaining popularity in other countries of the world due to improved quality of water flowing from drained agricultural fields to surface water. The practice has been tested on research facilities in several countries including Lithuania [ 40 ], Sweden [ 41 ], Denmark [ 39 ], Italy [ 42 ], China [ 43 , 44 ], Iran [ 45 ], India [ 46 ], Japan [ 47 ], and Egypt [ 48 ]. Unfortunately, the results of experimental field studies usually include a short measurement period of CD effectiveness.…”