International Research Journal of Agricultural Science and Soil Science (ISSN: 2251-0044) Vol. 3(10) pp. 343-352, October, 2013 DOI: http:/dx.doi.org/10.14303/irjas.2013.109 Available online http://www.interesjournals.org/irjas Copyright 2013 International Research Journals Full Length Research Paper Evaluation of salinity and sodicity parameters: Bannu SCARP, Pakistan Mahmood Alam Khan 1, Taj Ali Khan 1, Muhammad Shahzad Khan 1, Tariq Usman Saeed 2*, Daulat Khan 1 1 Department of Agricultural Engineering, University of Engineering and Technology Peshawar, Pakistan *2 Transport Department, Government of Khyber Pakhtunkhwa, Peshawar Pakistan *Corresponding author`s e-mail: tariqusaeed@gmail.com ABSTRACT The research article evaluates the soil salinity and sodicity levels in the area stuck by water logging and salinity. Soil Sampling was done in the SCARP area of Bannu Division, Khyber Pakhtunkhwa province of Pakistan between December 2010 to March 2011 and tests were performed in Environmental Engineering Lab at Department of Agricultural Engineering, University of Engineering and Technology, Peshawar Pakistan. For this purpose twenty three sampling points were randomly selected and samplings were made at three different depths ranging from 0-0.25, 0.25-0.5 and 0.5 to 1 meter. Soil samples were analyzed and results were prepared for parameters like Electrical Conductivity of Soil Saturate Extract, Na +, Ca ++, Mg ++, K +, CO 3 --, HCO 3 -, Cl -, SAR and RSC. The average value of EC e was 5.69 ds/m which revealed that the soil is saline in nature. The average concentration of Na +, Ca ++, Mg ++, K +, CO 3 --, HCO 3 -, Cl -, SAR and RSC were determined as 2.87 meq/l, 0.28 meq/l, 0.08 meq/l, 1.14 meq/l, 0.78 meq/l, 2.25 meq/l, 18.12 meq/l, 8.46 and 2.67 meq/l respectively. The average values of EC e and SAR are 5.69 ds/m and 8.46 respectively. Based on these findings, the soil of the study area is classified as saline. The average RSC value of the soil is 2.67 meq/l. These average RSC values indicate that concentrations of carbonates and bi-carbonates are high, which cause calcium and magnesium to precipitate in the soil. The results suggested that the study area is facing an acute concentration of soluble salts and reclamation measures are needed to bring this area under cultivation. Irrigation water quality analysis, reclamation of soil and provision of proper drainage system are recommended. Keywords: Soil salinity; Sodicity; Anions; Cations; Standard Deviation; Coefficient of Variation; SCARP (Salinity Control and Reclamation Project) INTRODUCTION Soils with high amounts of soluble salts are called saline soils. They often exhibit a whitish surface crust when dry. The solubility of calcium sulphate or gypsum (CaSO 4 ) is used as the standard for comparing solubilities of salts. Salts more soluble than gypsum are considered to be soluble and cause salinity. Examples are sodium sulphate or Glauber s salt (Na 2 SO 4 ) and sodium chloride, or table-salt (NaCl). Salts less soluble than gypsum are considered insoluble and do not cause salinity. Calcium carbonate (CaCO 3 ) or lime is an example of an insoluble salt. Soils high in sodium (sodic soils) may present physical restrictions to plant growth. Sodium (Na + ) is a positively charged component, or cation, of many salts. Sodium problems are due to its behavior when attached to clay particles. If 15 percent or more of the clay adsorption sites are occupied by sodium (sodium-clay), poor physical condition of the soil often restricts root growth and makes tillage difficult (Seelig, 2000). Rise in water table levels contributes significantly to salinity/sodicity development (Khan and Akram, 1986). Increasing soil salinity is a serious land degradation issue, with the area affected by dry land salinity esti-
344 Int. Res. J. Agric. Sci. Soil Sci. mated to be approximately 4 million ha in 2000, and is predicted to increase to 20 million ha by 2020 (National Land and Water Resources Audit (NLWRA). Agricultureinduced salinity and sodicity not only influences the chemical and physical characteristics of soils but also greatly affects soil microbial and biochemical properties (Rietz and Haynes, 2003). Soil salinization is one of the major factors that contribute to land degradation and decrease in crop yield (Anjum et al., 2005). It was reported that salinity in the arid and semi-arid regions of the world is a serious threat to agriculture (Rao et al., 2002). Production of grain legumes is severely reduced in salt-affected soils because their ability to form and maintain nitrogen fixing nodules is impaired by both salinity and sodicity (alkalinity). (Shah and Shah, 2011) found that salinity is usually combined with high ph conditions, due to the presence and enrichment of calcium carbonate in the upper most soil layers in the arid and semi-arid regions of Pakistan. (Khattak et al., 2002) evaluated the impacts of groundwater on soil and crops in District Karak (arid region). Soil deterioration and reduction in crop yield were noted due to water salinization. Tavakkoli et al. 2010 concluded that multiple factors contributing to subsoil constraints include salinity, sodicity, and high concentrations of chloride which are present in many rain-fed farming soils of Southern Australia. Moradi and Abdelbagi 2007 found that salinity is a widespread soil problem limiting productivity of cereal crops worldwide. Study Area This area lies between 32.70 o to 32.78 o N latitude and 70.70 o to 70.72 o E longitude with central coordinates of 32.73 o N and 70.71 o E. Zone-A of Bannu SCARP is situated in Lakki Marwat district of Khyber Pakhtunkhwa, Pakistan, about 180 km south of Peshawar, comprising an area of about 3241 ha with total perimeter of 25.37 km (Figure 1). This zone suffers a very severe water logging and salinity problem. Main villages in Zone-A of Bannu SCARP are: Kot Kashmir, Gandi Khan Khel, Pahar Khel and Serai Gambila (National Drainage Program (NDP) PC-I Proforma, Bannu SCARP-II, NWFP Pakistan. 2002). Figure 1 shows the study area and sampling locations. Geology and Hydrogeology Main constituents of soil in district Lakki Marwat are deep excessively drained calcareous and coarse textured (sand and loamy sand) developed from the silwalik sand stone of Shin Ghar and Marwat range piedmont material. The fine textured soils (sandy clay and clay loam) of the area are developed from mixed material derived from variety of rocks of Bhittani and Waziristan ranges. The soils occur on leveled to nearly leveled position in piedmont plains. Climate of the area is arid to semi-arid and sub-tropical continental. The soils are used for dry farming and torrent water cultivation (Population Census Organization, Statistics Division of Pakistan. District Census Report of Lakki Marwat. 2000). There are two main sources of irrigations, Kurram and Gambila Rivers. Kurram and Gambila rivers provide surface irrigation by canal systems, while ground water is lifted by installing tube wells. The study area suffers severely from waterlogging and salinity. Texture of the soil varied from clay loams, silty and fine sandy clay loams. The main factors contributing to waterlogging problem are: seepage from canals, inequity in the civil canal system (due to existing and prevailing system of water distribution), unawareness of farmers of the area about irrigation scheduling and unavoidable losses from the irrigation system. The area is facing an acute problem of soil salinity and the levels of soil salinity in this area are needed to be identified. The specific objectives of the study area include; investigation of major cations and anions, and determination of soil salinity and sodicity levels (ECe, SAR and RSC) in Zone A of Bannu SCARP. METHODOLOGY This study was conducted from December 2010 to March 2011, in which soil samples were collected and then analyzed for salinity and sodicity status of the study area. The project area was surveyed and twenty-three (23) sampling points were selected randomly. From each sampling point at three different depths (0 0.25, 0.25 and 1m) soil samples were taken with the help of auger. Thus total of sixty nine (69) soil samples were collected from the whole study area (Figure-1). All the soil samples were carefully taken to the laboratory in plastic bags for its various characteristics following methods described by Richards, 1959. RESULTS AND DISCUSSION The analysis results have been presented in Figures 2 to 11. Electrical conductivity of the soil extract Figure 2 shows average EC e concentrations of the soil at each sampling location. Soil samples taken from 0 0.25 m depth at different locations had an average EC e value of 6.15 ds/m, standard deviation of 2.84 ds/m and coefficient of variation of 46.30%. The average value of EC e of soil samples taken from depths 0.25 m was 5.74 ds/m, standard deviation of 2.6 ds/m and coefficient of variation of 45.40%. Similarly, the average value of EC e of the soil samples taken from 1 m depth was
Khan et al. 345 Khyber Pakhtun khwa Gilgit Baltistan (a) Fa ta Azad Kashm ir Pun jab Bal ochista n Sin dh (b) N LM 15 LM 16 LM 17 LM 3 LM 19 LM 10 Drain Cannal Road Sam pling point Boundary LM 23 LM 13 LM 12 2 0 2 4 Kilometers Figure 1. (a) Map of Pakistan and (b) Study area showing sampling locations 14.00 1 ECe ECe Avg 1 ECe (ds/m) 8.00 6.00 4.00 0 2 3 5 6 7 9 3 Figure 2. Electrical Conductivity of the soil at various locations
346 Int. Res. J. Agric. Sci. Soil Sci. 5.00 4.50 Na Na Avg 4.00 3.50 3.00 Na (meq/l) 2.50 1.50 1.00 0 2 3 5 6 7 9 3 Figure 3. Sodium concentration of the soil at various locations 5.18 ds/m, standard deviation of 2.55 ds/m and coefficient of variation of 49.30%. The average values also indicated that salts were high in the upper soil layers as compared to the lower soil layers. Results reveal that soil salinity was decreased from top to bottoms. The overall average value of EC e has been 5.69 ds/m. Richards, 1959 reports that soils having EC e greater than 15 ds/m are strongly saline. James et al. 1982 reported that the soils having EC e greater than 4 ds/m are classified as saline soils. Soluble cations of soil extract The most common cations of soils determined in the laboratories were Sodium, Calcium, Magnesium, and Potassium. Sodium concentration of the soil extract Average sodium concentrations of the soil at each sampling location are presented in Figure 3. Sodium concentration of the soil samples, which were taken from 0-0.25 m depths had an average value of 2.86 meq/l, standard deviation of 0.84 meq/l and coefficient of variation of 29.31%. Average value of sodium concentration from 0.25 m depth was 2.91 meq/l, standard deviation of 0.72 meq/l and coefficient of variation of 24.96%. Similarly average value of sodium concentration of the soil samples taken from 1 m depth was 2.86 meq/l, standard deviation of 0.73 meq/l and coefficient of variation of 25.54%. The overall average sodium concentration of the soil was 2.87 meq/l. Calcium concentration of the soil extract Graphical presentation of average calcium concentration of the soil samples at each sampling location can be seen in Figure 4. Calcium concentration for the soil samples taken from 0-0.25 m depths, had an average value of 0.35 meq/l, standard deviation of 0.20 meq/l and coefficient of variation of 57.18%. Average value of calcium concentration of the soil samples taken from 0.25 m depth was 0.26 meq/l, standard deviation of 0.19 meq/l and coefficient of variation of 76%. The average concentration of calcium of the soil samples taken from 1 m depth was 0.23 meq/l, standard deviation of 0.17 meq/l and coefficient of variation of 74.40%. The average value of all the depths reveals that calcium content decreased with depths. The overall average value of calcium remained as 0.28 meq/l. Magnesium concentration of the soil extract Figure 5 shows average concentration of magnesium of soil samples at each sampling location. Soil samples, taken from 0-0.25 m depths, had an average magnesium concentration of 0.08 meq/l, standard deviation of 0.05 meq/l and coefficient of variation of
Khan et al. 347 0.60 Ca Ca Avg 0.40 Ca (meq/l) 0.30 0.20 0.10 0 2 3 5 6 7 9 3 Figure 4. Calcium concentration of the soil at various locations 0.18 0.16 Mg Mg Avg 0.14 0.12 0.10 Mg (meq/l) 0.08 0.06 0.04 0.02 0 2 3 5 6 7 9 3 Figure 5. Magnesium concentration of the soil at various locations 61.70%. The average magnesium concentration of soil samples taken from 0.25-0.5 m depths was 0.08 meq/l, standard deviation of 0.05 meq/l and coefficient of variation of 57.65%. The average value of magnesium concentration of the soil sample from 1 m depths was 0.07 meq/l with standard deviation of 0.03 meq/l and coefficient of variation of 47.70%. The average values for all depths show that magnesium content remained almost same with depth. Its overall average value remained as 0.08 meq/l. Potassium concentration of the soil extract The average potassium concentration of the soil samples at each sampling location has been shown in Figure 6. Soil samples taken from 0-0.25 m depths, had an average value of potassium was 1.34 meq/l, standard deviation of 0.57 meq/l and coefficient of variation 43.01%. The average values of potassium concentration of soil samples taken from 0.25 - m depth, was 1.11 meq/l, standard deviation of 0.45 meq/l and coefficient of
348 Int. Res. J. Agric. Sci. Soil Sci. 2.50 K K Avg 1.50 K (meq/l) 1.00 0 2 3 5 6 7 9 3 Figure 6. Potassium concentration of the soil at various locations 16.00 14.00 SAR SAR Avg 1 1 SAR 8.00 6.00 4.00 0 2 3 5 6 7 9 3 Figure 7. Sodium Adsorption Ration of the soil at various locations variation of 40.95%. The average values of potassium concentration of the soil samples taken from 1 m depths, was 0.97 meq/l with standard deviation of 0.44 meq/l and coefficient of variation of 45.10%. The average values reveal that potassium content decreased with depths from 1.34 to 0.97 meq/l. The 1 m depth results show that the soil has low content of potassium in the lower depths. The overall average value of Potassium concentration was 1.14 meq/l. Sodium absorption ratio (SAR) of the soil extract Average SAR levels of the soil samples at each sampling location can be seen in Figure 6. Soil samples taken from depths of 0-0.25 m, had an average value of SAR as 7.77, standard deviation of 5.34 and coefficient of variation of 68.70%. The average value of SAR of the soil samples taken from 0.25 - m depths, was 8.63,
Khan et al. 349 2.50 CO3 CO3 Avg 1.50 1.00 CO3 (meq/l) 0 2 3 5 6 7 9 3 Figure 8. Carbonate concentration of the soil at various locations standard deviation of 3.98 and coefficient of variation of 46.10%. The average values of soil samples taken from 1 m depth was 8.99, standard deviation of 4.49, and coefficient of variation of 50.10%. The overall average value for SAR was 8.46. James et al. 1982 reveals that soils with EC e greater than 4 ds/m and SAR less than 13 can be classified as saline soil. The average values reveal that SAR for all soil depths had increased from top to lower soil layers. Soil investigation division of WAPDA (Water and Power Development Authority (WAPDA) reported that SAR of all soils either decreases or remains unchanged, when irrigated with water having EC w of 1.5 ds /m, SAR less than 10 and RSC more than 5.0 meq/l. Soluble anions of the soil extract The most common anions of soil determined in the laboratories were Carbonate, Bicarbonate and Chloride. Carbonate concentration of the soil extract Average concentration of carbonates of the soil samples at each sampling location of the study area are seen in Figure 8. The average carbonates concentration of the soil samples, taken from 0-0.25 m depths had an average value of 0.78 meq/l, standard deviation 0.53 meq/l and coefficient of variation 68%. The average value of carbonates of the soil samples taken from 0.25 - m depths was 0.69 meq/l, standard deviation of 0.47 meq/l and coefficient of variation of 67.60%. The average concentration of carbonate of the soil samples taken from 1 m depth was 0.85 meq/l, standard deviation of 0.84 meq/l and coefficient of variation of 99%. The overall average concentration of carbonate of the soil samples was 0.78 meq/l. Bicarbonate concentration of the soil extract Figure 9 shows the average concentration of bicarbonates of the soil samples at each sampling location. The average bicarbonate concentration of the soil samples, taken from 0-0.25 m depth had an average value of bicarbonate as 2.34 meq/l, standard deviation of 0.86 meq/l and coefficient of variation of 36.80%. The average value of bicarbonate concentration of soil samples taken from 0.25 - m depths was 2.26 meq/l, standard deviation of 1.23 meq/l and coefficient of variation of 54.60%. The average concentration of bicarbonate of the soil samples taken from 1 m depths was 2.17 meq/l, standard deviation of 0.89 meq/l and coefficient of variation of 41%. The overall average value of bicarbonate was 2.25 meq/l. Chloride concentration of the soil extract The average chloride concentration of the soil samples at each sampling location has been shown in Figure 10. The average chloride concentration of the soil samples, taken from 0-0.25 m depth had an average value of 21.69 meq/l, standard deviation of 17.52 meq/l and coefficient of variation of 80.75%. The average chloride concentration of soil samples taken from 0.25-0.5 m depths was 18.11 meq/l, standard deviation of 14.53 meq/l and coefficient of variation of 80.20%. Similarly average value of chloride concentration of the soil samples taken from 1 m depths was 14.53 meq/l,
350 Int. Res. J. Agric. Sci. Soil Sci. 4.50 4.00 HCO3 HCO3 Avg 3.50 3.00 HCO3 (meq/l) 2.50 1.50 1.00 0 2 3 5 6 7 9 3 Figure 9. Bicarbonate concentration of the soil at various locations 6 Cl Cl Avg 5 4 Cl (meq/l) 3 2 1 0 2 3 5 6 7 9 3 Figure 10. Chloride concentration of the soil at various locations standard deviation of 10.19 meq/l and coefficient of variation of 70.09%. The average values of all the depths reveal that chloride contents had increased with depth. The overall average value of chloride concentration was 18.12 meq/l. Residual sodium carbonate (RSC) level of the soil extract Figure 11 shows average values of Residual Sodium Carbonate (RSC) of the soil samples at each sampling location of the study area. The average value of RSC of the soil samples, taken from 0-0.25 m depths had an average value of 2.68 meq/l, standard deviation of 1.31 meq/l and coefficient of variation of 48.60 %. The average RSC values of the soil samples taken from 0.25-0.5 m depth, was 2.62 meq/l, standard deviation of 1.66 meq/l and coefficient of variation of 63.58 %. The average RSC value of soil samples from 1 m depths was 2.73 meq/l, standard deviation of 1.32 meq/l and coefficient of variation of 48.50%. The average values of all the soil samples taken from 0.25 1 m
Khan et al. 351 5.00 4.50 RSC RSC Avg 4.00 3.50 3.00 2.50 1.50 1.00 0 2 3 5 6 7 RSC (meq/l) 9 3 Figure 11. Residual Sodium Carbonate concentration of the soil at various locations depths indicate that the RSC had increased with depth from 2.68 to 2.73 meq/l. However, in the subsurface layer of 0.25-0.5 m depths, RSC values had decreased. Hussain, 1967 reported that the soil with high RSC values concentration of salts in the top layer had negligible effect on the plant growth. However, the adverse effect was faster when both the components i.e. the salt concentration and residual sodium carbonate were high. The overall average value of RSC was 2.67 meq/l. CONCLUSION The following conclusions are drawn from this research study. The average values of EC e and SAR are 5.69 ds/m and 8.46 respectively. Based on these findings, the soil of the study area is classified as saline. The average RSC value of the soil is 2.67 meq/l. These average RSC values indicate that concentrations of carbonates and bicarbonates are high, which cause calcium and magnesium to precipitate in the soil. Irrigation water quality analysis, reclamation of soil and provision of proper drainage system are recommended. Competing interests Authors have declared that no competing interests exist. Authors Contributions This work was jointly accomplished by the whole team. All the authors read and approved the final manuscript. REFERENCES Anjum R, Ahmed A, Rahmatullah, Jahangir M, Yousaf M (2005). Effect of Soil Salinity/Sodicity on the Growth and Yield of Different Varieties of Cotton. International Journal of Agricultural Biology. 7(4):606 608. Available: Australian Agronomy Conference, 2010 15th AAC Crop Production Subsoil Constraints Hussain M (1967). Studies on the Use of Saline Ground Water for Irrigation. Directorate of Land Reclamation, Punjab, Lahore. 2(14). James LG, Hanks RJ, Jurinak JH (1982). Modern Irrigated Soils. John Wiley and Sons. New York. Khan GS, Akram M (1986). Dynamics of Ground Water of Semi-arid in Pakistan. Abs. XIII. Cong. International Society of Soil Science. Hamburg (Germany). 459. Khattak MS, Khan TA, Alamgir M (2002). Ground Water Chemicals Concentration and Standards for Crops with Particular Reference to Dug Wells in District Karak. Sarhad J. Agric. 18 (2): 215-224 Moradi F, Abdelbagi Ml (2007). Responses of Photosynthesis, Chlorophyll Fluorescence and ROS-Scavenging Systems to Salt Stress During Seedling and Reproductive Stages in Rice. Annals of Botany. 1-13. International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines National Drainage Program (NDP) PC-I Proforma, Bannu SCARP-II, NWFP Pakistan. 2002. National Land and Water Resources Audit (NLWRA) (2002). National Dry land Salinity Assessment. National Land and Water Resources Audit, Commonwealth of Australia, Canberra. Population Census Organization, Statistics Division of Pakistan. District Census Report of Lakki Marwat. 2000. Rao DLN, Giller KE, Yeo AR, Flowers TJ (2002). The Effects of Salinity and Sodicity upon Nodulation and Nitrogen Fixation of Chickpea (Cicer arietinum). Annals of Botany. 89:563-570. Richards LA (1959). Diagnosis and Improvement of Saline and Alkali Soils. Agriculture Hand book No. 60. United States Department of Agriculture, Washington, D.C. Rietz DN, Haynes RJ (2003). Effects of irrigation-induced salinity and sodicity on soil microbial activity. Soil Biology and Biochemistry. 35:845-854 Seelig BD (2000). Salinity and Sodicity in North Dakota Soils. N Extension Service, North Dakota State University of Agriculture and Applied Science, and U.S. Department of Agriculture Cooperating. Shah SA, Shah Z (2011). Changes in Soil Microbial Characteristics with Elevated Salinity. Sarhad J. Agric. 27(2):233-244.
352 Int. Res. J. Agric. Sci. Soil Sci. Tavakkoli E, Jones B, Coventry S, Rengasamy P, McDonald G (2002). On-farm Assessment of Sub-soil Salinity and Sodicity Constraints to Barley Production in Southern Australia. Proceedings of 15th Agronomy Conference 2010, 15-18 November 2010, Lincoln, New Zealand. Accessed on: 09/04/2013 Water and Power Development Authority (WAPDA). Water Quality and Soil. A note on Soil Studies. Monitoring and Planning Organization, WAPDA Pakistan. 1974. How to cite this article: Khan MA, Khan TA, Khan MS, Saeed TU, Khan D (2013). Evaluation of salinity and sodicity parameters: Bannu SCARP, Pakistan. Int. Res. J. Agric. Sci. Soil Sci. 3(10):343-352