Effect of poor quality water on the chemical properties of the salt affected soils and performance of rice.

Abstract

A micro-lysimeter (1.0 meter deep and 0.3 m internal diameter) experiment was conducted to study the effect of different quality irrigation water on the soil chemical properties and their influence on growth, yield and other biometric parameters of rice (variety CSR 36). Irrigation water treatments included viz., normal tap water (NTW), dilute saline water (DSW, ECiw 5.0 dS m-1 and SAR 5.0 mmol1/2 L-1/2); concentrated saline water (CSW, ECiw 10.0 dS m-1, SAR 5.0 mmol1/2 L-1/2) , dilute alkali water (DAW, RSC 2.5 me L-1) and concentrated alkali water (CAW, RSC 10.0 me L-1). Three different type of sandy loam soils viz., normal (pH2 7.5 and ECe 1.0 dS m-1), saline (pH2 7.7 and ECe 10.6 dS m-1) and alkali (pH2 9.15 and ECe 2.9 dS m-1) soils were used for this investigation. Saline and alkali water irrigation affected the EC, pH and exchangeable sodium percentage (ESP) of normal, saline and alkali soils. In normal soil, ECe increased 8.5 to 12.5 times in DSW and CSW, respectively as compared to initial experimental soil whereas, it was increased 3.2 to 4.8 times, in the alkali soil. Decrease in ECe was observed in all water treatments except CSW in saline soil as compared to initial experimental soil. Increase in pH of normal and saline soil was more pronounced in case of CAW as compared to alkali soils but decrease in pH was observed in normal, saline and alkali soils on application of DSW and CSW. Significant increase in ESP (exchangeable sodium percentage) was observed in DAW and CAW particularly in alkali soils but it in case of normal and saline soil it was observed in surface samples. ESP decreased in case of DSW and CSW in alkali soil. Cations and anions build up was more pronounced in normal soil followed by alkali and saline soils as compared to exp soil. Rice yield was at par (93%) in DAW as compared to NTW in all soils, whereas, use of CAW reduced grain yield up to 50% for normal and saline soil and in case of alkali soil it is reduced to 15% for alkali soil. Yield was further reduced to 33% in DSW for normal and saline soil and 19% for alkali soil. Yield in CSW was found negligible as total loss of crop was observed in all soils.