17. Sustainable Pearl Millet Production Using Saline Groundwater under Drought Condition

A validated physical based one dimensional simulation model SWAP (Soil Water Atmosphere Plant) was used to formulate guidelines for the use of saline groundwater in Pearl millet grown on sandy loam soil considering non-occurrence of rainfall during crop growth season. The simulation study considered the combination of common pre-sown canal irrigation water of 6 and 8 cm depths and postsown irrigations of 4, 6, 8 and 10 cm depth each with saline groundwater ranging from 4 to 14 dS/m. The Water Management Response Indicators, WMRI were used to evaluate the performance of irrigation practice. The study revealed that sustainable Pearl millet production (ETrel. ≥ 0.60) could be achieved with 4 and 6 dS/m saline groundwater quality under drought conditions by providing three post-sown irrigation of 8 cm each for both qualities of water at critical crop growth stages based on crop phenology with 8 cm pre-sown canal irrigation. This practice resulted in lowering of salinity hazards index SHI (2.66 to 1.85 as compared to light (4 cm)) irrigations thereby facilitating the root water uptake. However, percolation losses increased from 20.74 to 31.08 with increased irrigation depths of 8 cm. The study further indicated that use of higher salinity (ECiw > 6 dS/m) groundwater for post-sown irrigation as such could not meet the sustainability criterion.