Reaction of Rainfed Barley to Water Salinity Amount in Spring Supplementary Irrigation

Supplementary irrigation in rainfed agriculture causes the increasing of crop yield and better using of water resources. The objective of this research was to investigate the effects of using of unconventional saline waters on supplementary irrigation of rainfed barley. The treatments included a rainfed (D) treatment and four water salinity levels with EC of 0.5 (S0), 6.7 (S1), 8.7 (S2) and 12 (S3) dS.m-1. When the barley grains filling, was performed the once spring irrigation based on deficiency of soil moisture. The yield amounts in D, S0, S1, S2 and S3 treatments were measured equal to 4005.8, 6449.08, 4918.32, 4260.08 and 3063.72 kg. ha-1 (biomass yield), 1973.18, 3174.16, 2438.48, 2112 and 1651.32 kg. ha-1 (straw yield) and 2032.62, 3227.92, 2479.84, 2148.08 and 1412.4 kg. ha-1 (grain yield), respectively. The results showed that for one dS.m-1 increasing of water salinity in supplementary irrigation, biomass, straw and grain were decreased (relative to rainfed), equal to 7.2%, 6.7% and 7.7%, respectively. Therefore, supplementary irrigation of barley up to salinity level of S2, was recommended for rainfed cultivation conditions. Also, water productivity in D, S0, S1, S2 and S3 treatments were calculated equal to 1.941, 2.618, 2, 1.73 and 1.243 kg.m-3, respectively. Typically, water productivity in rainfed agriculture is more than irrigated crop cultivation. However, the results of this research showed that in supplementary irrigation of barley up to salinity level of S1, the amount of water productivity will be more than rainfed cultivation conditions. Therefore, in addition of quality water, the using of saline water (at the crop tolerance level) for supplementary irrigation of barley, causes the increasing of crop yield, food security and optimal management of water resources.