Sekhon, K.S.Sidhu, Simranpreet Kaur2018-07-142018-07-142018http://krishikosh.egranth.ac.in/handle/1/5810060205The increasing demand for irrigation water to secure food for ever growing global population with declining fresh water resources carves the path for introduction of alternative ways of using saline water. Long-term irrigation with saline water causes accumulation of salts in the rhizosphere, inducing increased osmotic potential of the soil solution thus impairing plant water and nutrient uptake. In arid-zone agriculture, where underground water is saline, more emphasis is being laid on use of desalinated water and conjunctive use. A long term on-going drip irrigated field experiment being conducted under the NHM sponsored project “Centre of excellence for utilization of brackish water for fruits and vegetable production in S-W Punjab” at PAU RRS Bathinda was selected to study the effect of different qualities of irrigation water namely canal (WQ1), desalinated (WQ2), saline (WQ3) and mixed CW: SW (WQ4) water and three fertigation levels [100% (F1), 80% (F2) and 60% (F3) of recommended NPK dose] on bell pepper and soil properties under un-mulched (M0) and mulched (M1) conditions. The results showed that highest fruit yield was obtained with WQ1, followed by WQ2 and WQ4, while lowest with WQ3. Reducing the salinity from EC 4.22 dSm-1 in WQ3 to EC 0.398 dSm-1 in WQ2 through desalination process, there was increase in fruit yield by 58%, irrespective of mulch and fertigation. Application of silver black polyethylene mulch (25µ) and increasing levels of fertigation significantly increased the fruit yield of bell pepper, irrespective of irrigation water quality. The concentration of Ca, Mg and S in leaves and fruits of bell pepper increased significantly with increasing salinity of irrigation water but Ca, Mg and S content in leaves and fruits of bell pepper in WQ2 was significantly lower than WQ1 at 60 DAT, 90 DAT and at maturity. The content of N, P and K in leaves and fruits decreased with increase in salinity of irrigation water; however, in WQ1 and WQ2 it was comparable at successive stages of growth up to maturity. The pH and electrical conductivity of soil increased significantly in WQ3 and WQ4 in comparison to WQ1 and WQ2 at pre-fertigation stage, and after 24 and 48 hours of 10th and 20th fertigation. Saline water (WQ3 and WQ4) increased the salinity build up away from the drip lateral to a greater extent than non-saline water (WQ1 and WQ2). Soil SAR values were also found to be higher in WQ3 and WQ4 under no mulch and moderated with the application of polyethylene mulch. However EC, pH and SAR values of soil with WQ2 were found to be quite similar to that of WQ1. Available N, P, K and organic carbon content of soil decreased with the increasing salinity of irrigation water and increased with increasing fertigation levels under M0 and M1 for surface (0-15 cm) and sub-surface (15-30 cm) layer of soil at all the sampling stages. To conclude, desalinated water or mixing canal and saline water in equal proportion with an acceptable yield loss can be used for irrigation to bell pepper under drip system in case of scarcity of good quality irrigation water.enThesis