Assessment of Selected Soil Properties and Soil Structural Stability Under Irrigation Schemes in Central and North Western Tigray, Ethiopia

Assessment of soil physicochemical properties and soil structural stability is an important issue to understand the status of soils under irrigated schemes and maintain optimum soil wellbeing. Therefore, it is hypothesized that the soil physicochemical properties, including bulk density (BD), texture, major soil nutrients such as nitrogen, available phosphorus (Av.P), organic carbon, exchangeable cations, and soil structural stability indices, are significantly affected under long‐term irrigated practices of the selected irrigation schemes of central and northwestern Tigray, Ethiopia. A total of 63 composite soil samples were collected from three irrigated schemes. Total nitrogen (TN) content across the irrigation schemes followed the order Meskebet > Dugub > Dura. Soil organic carbon (SOC) concentration in Dugub was significantly lower than those in Meskebet and Dura irrigation schemes. The Dura irrigation scheme has the lowest (1.12 ± 0.07) BD due to higher SOC. On the other hand, Dugub had a higher mean value in BD. Dura was dominated by clay (51.50 ± 7.98%). Meskebet had the highest sand (31.0 ± 5.23%) and silt (44.25 ± 2.91%) content. pH increased from Meskebet (6.83) to Dugub (7.23) and Dura (7.85). The Dura irrigation scheme had the highest electrical conductivity (EC) of 0.36 mS/cm, which could be due to poor water management and long‐term accumulation of salt. Dugub has the highest (15.33 ppm) Av.P, while Meskebet has the lowest (8.34 ppm) Av.P due to low SOC. The cation exchange capacity (CEC) showed an increasing order across the irrigation schemes as Meskebet (16.39 cmol (+)/kg) < Dugub (21.69) < Dura (26.36). The highest (22.85 meq/kg) calcium (Ca +2 ) content was found in Dura irrigation scheme. The soil structural stability index (SSSI) in all irrigation schemes was below the recommended level (< 5%). Furthermore, all the irrigation schemes have a medium sodium hazard. Generally, the three sites have variability in soil fertility, salinity, and alkalinity characteristics and are structurally degraded. Therefore, there is a need of site‐specific nutrient and water management practices for sustainable agricultural use of the schemes.