Influence of Intensive Cultivation and Irrigation on Soil Properties in the Jordan Valley, Israel: Recrystallization of Carbonate Minerals

This is part of a study regarding the effect of intensive cultivation on the soil properties in the Jordan Valley in an area where a decline of crop yield was detected. The high pCO 2 values in the cultivated soil (−1.3 Atm) and the large amount of irrigation water applied enhanced the processes occurring in the CaCO 3 − HCO 3 ‐ − CO 2 system. The largest difference in the amount of dissolution and recrystallization between the cultivated and undisturbed soils was found in the lower part of the profile (horizon BCa and B3). The total amount of CaCO 3 leached from the cultivated soil was about 7% of the total carbonate (about 500 metric tons/ha). Most of this loss was from the finer‐grained fraction. An even larger effect was found on the amount of recrystallized carbonate in the soil (about 11% of the total carbonate). A decrease was observed in the bulk density of the upper soil horizons in the cultivated soil relative to the undisturbed soil. The highest bulk density of the cultivated soil was found at a depth of about 1 m compared to the maximum in the 0‐ to 15‐cm depth in undisturbed soil.