Dynamics of Hydraulic and Physio-chemical Characteristics of Soils in Potohwar Region

Abstract

Rainfed regions are those where cultivation mostly depends upon rainfall. The climate of Pakistan is uneven and almost two-third of the country has an arid type climate. A significant population is feeding on Barani agriculture in Pakistan. Potohwar plateau is an upland area lying between the Indus and Jhelum River mainly comprising of Attock, Chakwal, Jhelum, and Rawalpindi districts with a total area of 28500 km2. Soil erosion and water management are the main constraints for agriculture production in this area. The present study has been conducted to evaluate the physiochemical and hydraulic characteristics of soil in this region and its impacts on crops/vegetation growth. For this purpose, 30 sites were selected based on a uniform grid of 30 km2 in the whole region. The samples for each site were taken by auger at three layers i.e. surface, middle, and bottom-up to 1 m depth. Soil texture, infiltration rate, and bulk density were found of each layer. By analysis of soil paste extract EC, pH, Na, Ca and Mg were found for the calculation of SAR. Results of the study reveal that soil was sandy to loam in the Attock district and patches of sandy clay loam in some parts of the Potohwar which can support low water demanding crops (gram, groundnut, and wheat crops as well as orchards). The infiltration rate was observed that variant between 20 mm/hr for medium soil and > 40 mm/hr for sandy soils (require special conservation practices). Bulk density of all soil samples was in the normal range, however, organic matter content was highly variable (0.5-1.5%) depending upon rainfall and natural vegetation. The pH of the whole region was in the range of 7.4-8 (neutral) and EC was between 35-120 dS/m. So, it is concluded that there is no salinity problem. Regression analysis was done among different parameters and most of the p values were > 0.05, which showed that the results were insignificant. Based on these results it is concluded that the soil of the Potohwar region is fully capable of, to produce a satisfactory yield of crop. Adoption of modern soil and water management practices can improve the potential of crop growth and orchard