Effect of Controlled Drainage for Alleviating Soil Problem

Water logging induced salinity is a common problem in many command areas of irrigation projects. Controlled drainage is the next level of logical step towards improving water management in irrigated agriculture and reducing the environmental impact on subsurface drainage flow. The experiment was carried out during 2015 under irrigated condition, to study the effect of controlled drainage for alleviating water logging and soil salinity. The design of experiment was spilt plot design. The main plot treatments were taken at 4 levels of spacing (S1=7.5 m, S2 = 10 m, S3 =12.5 m, S4 =15 m) and subplot treatments were taken at 2 levels of drain depth and drain diameter (D1 = 75 cm, D2 = 60 cm; d1 = 75 mm, d2 = 63 mm). The result showed that the treatments of 75 cm (D1) of drain depth areas showing more depth to water table in all days of observations. The drain discharge rates were high in 7.5 m (S1) spacing when compared to all other spacing due to the influence of more area of contributing drain pipes (0.44 cm/day). The average paddy yield in the system installed field was 3.58 t/ha and the control plot was 2.2 t/ha. The results showed that the treatments of 7.5 m drain spacing at 75 cm depth with 75 mm diameter (S1D1d1) recorded high value in drainage coefficient and depth to water table. From the economic viability, it was observed that the 15 m drain spacing at 75 cm drain depth with 75 mm diameter (S4D1d1) were economically viable with the highest profit than the other treatments.