RECLAMATION OF SALINE AND WATERLOGGED SOILS IN MUTLURU CHANNEL COMMAND OF KRISHNA WESTERN DELTA, ANDHRA PRADESH STATE, INDIA

摘要

There is about 35,000 ha of salt-affected, water logged lands in the irrigated command ofrnKrishna Western Delta in Andhra Pradesh state of India. A pilot study of installing openrnsubsurface drainage to improve crop yields was conducted in 22.3 ha. of the Mutluru ChannelrnCommand. In this Pathareddy Palem drainage pilot area, the 0.25-0.35 m. deep open drainrnlaterals were spaced from 60 to 80 m apart. Paddy rice was grown during the kharif season (July-November monsoon cropping season) of 2005 and 2006. The paddy rice grain yield was 2.2 t ha~(-1) during pre-drainage, and after drainage, increased to 2.9 and 3.8 t ha~(-1) in the kharif 2005 and 2006 seasons, respectively.rnEight observation wells, installed to 3.4 m depth in Mutluru channel command and measuredrnweekly, showed that the water table at near ground surface was lowered to as much as 3 m depth and EC of the ground water ranged from 18 to 44 dS/m. Soil Ece was measured at grid sites sampled at 0-15, 15-30, 30-60 and 60-100 cm depth intervals. In the summer of 2005 about 6% of the 62 samples were non saline (< 4 dS/m) and 19% had Ece ranging from 4-8 dS/m. In the summer of 2006, 29% of the samples were non saline and 15% had Ece of 4-8 dS/m. The open subsurface drainage system helped in leaching soluble salts from the root zone increasing the paddy grain yields. This pilot project proved that installation of open surface drainage systems in the Krishna Western Delta Command will be beneficial to crop production and increase economic returns to farmers.