Chemical Properties of the Salt-affected Soils and Performance of Wheat (Triticum aestivum) with Saline and Alkali Water Irrigation

Abstract

Effect of different quality of irrigation water viz., normal tap water (NTW, EC 0.7 dS m-1), dilute saline water (DSW, EC 5.0 dS m-1 ; SAR 5.0 mmol ½ L-½), concentrated saline water (CSW, EC 10.0 dS m-1 ; SAR 5.0 mmol ½ L-½), dilute alkali water (DAW, RSC 2.5 me L-1) and concentrated alkali water (CAW, RSC 10.0 me L-1) on the soil chemical properties and its impact on growth and yield of wheat (cv.KRL 213) was evaluated in normal (pHs 7.5, ECe 1.0 dS m-1), saline (pHs 7.7, ECe 10.6 dS m-1) and alkali (pHs 9.15, ECe 2.9 dS m-1) sandy loam soils in the micro-lysimeter. The ECe increased by 9.5, 12.5 and 5.5, 7.0 times due to DSW and CSW irrigation in normal and alkali soils, respectively as compared to initial values, whereas decrease in ECe was observed in all water treatments except CSW in saline soil. Increase in pHs of normal and saline soils was more pronounced in case of NTW, DAW and CAW as compared to alkali soil. On application of DSW and CSW, decrease in pHs was observed in alkali soil, whereas it remained constant in normal and saline soils as compared to initial. Exchangeable sodium percentage (ESP) increased with all water treatments in normal, saline and alkali soils. This increase was more pronounced under NTW, DAW and CAW in alkali soil as compared to normal and saline soils. Sodium concentration in saturation paste increased by 15 to 17 times in normal soil, 3.5 to 4.5 times in alkali soil under DSW and CSW, respectively. Sodium leaching was observed in saline soil under all water treatments except under CSW where it increased to 1.2 times. Sodium build-up was increased 1.5 to 2.0 times under all water treatments in normal, saline and alkali soils as compared to post rice sodium concentration. Increase in organic carbon content was observed in surface samples in normal soil, whereas it was not as pronounced in saline and alkali soils. Calcium carbonate increased significantly in all depths in three soils under DAW and CAW. Wheat yield reduced approximately by 4, 11 and 34 per cent under normal, saline and alkali soils, respectively in DAW as compared to NTW, whereas CAW reduced grain yield by 31 per cent in normal, 87 per cent in saline and near total loss of crop was observed in case of alkali soil as compared to NTW. The DSW reduced yield by about 22 per cent each in normal and saline soils and about 70 per cent in alkali soil. Application of CSW reduced yield by 70 per cent in normal soil, whereas near complete loss of crop was observed in saline and alkali soils as compared to NTW.