Zahir Rawajfih

Boron deficiencies in alluvial soils of Jordan valley

Jordan Valley is the most important irrigated area for crop production in Jordan. Deficiency symptoms of micronutrient elements have been observed. To appraise the status of hot water extractable B in the soils of the Jordan Valley, 15 profiles were sampled to represent the various types of soils in the valley. The majority of the profiles studied contained less than 0.5 mg kg‐1 water‐soluble B, which is considered too low to supply sufficient B for normal plant growth. All the profiles studied are high in clay content and highly calcareous. These two factors may have contributed to the low water‐soluble B in these soils. The heavy texture of the soils also led to the fairly uniform distribution of B with depth in the great majority of the profiles.

Morphological, chemical, and physical characteristics of shrink‐swell soils in a mediterranean semiarid region

Abstract Heavy clay soils with swell‐shrink properties comprise most of the arable land in northern Jordan. These soils are classified as Vertisols. Vertisols occupy a large and important part of the agricultural land in Jordan where rainfed agriculture is practiced. Five sites were selected to represent Vertisols occurring in different precipitation zones. Soil characterization was carried out to provide useful information to understand the genesis and behavior of these soils. Vertisols in northern Jordan occur on flat to gently sloping plains. Clay, silt, and sand fractions were uniformly distributed indicating active pedoturbation. Clay content is moderate to high, and the higher the rainfall the higher the clay content. The high cation exchange capacity (CEC)/clay ratio suggest montmorillonitic and mixed mineralogy. Calcium (Ca) was the most dominant extractable cation followed by magnesium (Mg), sodium (Na), and potassium (K). The similar patterns of distribution for the electrical conductivity value...