IMPROVING BARLEY PRODUCTION UNDER DEFICIENT IRRIGATION WATER AND MINERAL FERTILIZERS CONDITIONS

Scarcity in irrigation water led to a gradual increase in water stress, consequently causing a decrease in dry matter, nitrogen uptake, productivity, and the protein content of barley. During two growing seasons, 2020–2021 and 2021–2022, two field experiments ensued to improve barley production in sandy soil under a deficit of irrigation water. The statistical analysis helped recommend the best factors to achieve maximum benefit with barley production under dry conditions and nitrogen mineral fertilizers. The significant variations occurred when irrigating with 60% full irrigation only, but were nonsignificant when irrigating with 80% full irrigation. Increasing the number of mineral fertilization doses to nine times resulted in higher nitrogen concentrations and availability inside the root-spreading area for the longest possible period without washing outside the root-spreading area by deep percolation than when given with three doses only. Irrigating with 80% full irrigation and nine dosages of mineral fertilization obtained the highest and best yield values. It resulted in a 20% reduction in irrigation water use and increased nitrogen fertilizer effectiveness through repeated application doses, resulting in increased productivity and less groundwater pollution. The simulation model received SALTMED model values with high accuracy for most of the studied traits; the R2 was not less than 0.97; therefore, it can function well under sandy soil conditions, which suffer from water scarcity.