Hilal, N. A., Khalaf, A. I. and Alwan, A. A. K. H. (2026) “Role of Phosphorus Source and Biochar Levels on Some Fertility and Productivity Characteristics of Barley Crop Grow in Gypsiferous Soils”, American Journal of Botany and Bioengineering, 3(2), pp. 34–44. doi: 10.51699/ajbb.v3i2.2028.