Saline Soils And Their Reclamation.pptx.

STUDY SLIDE

1. Saline Soils And Their Reclamation Presented by : Noshi Hamid 50 Sarah Ashfaq 51 Samina Bibi 52 Afia Shabir 53 Muhammed Ramzan 54 Zeeshan Amjid 56 Noor Fatima 57 Binish Asif 58 BS 8 th Semester ADP Replica Presented To : Dr. Amna Imran Institute of Botany, University of the Punjab 1

2. Contents Introduction Differences between saline, saline sodic and sodic soils Salt tolerance and mechanism Examples Plants in moderate salinity Plants in field conditions Reclamation and management practices Soil salinity problems in Pakistan Conclusion References

3. Introduction Soil containing sufficient amount of soluble salts to interfere with germination and growth of most crops plants are classified as saline. The term reclamation of saline soils refers to the  methods used to remove soluble salts from the root zone .

4. Difference between saline, saline sodic and sodic soils 1. Saline ( Non-sodic soils) EC > 4 ds/m SAR < 15 PH < 8.5 Neutral salts Calcareous pH = 8.2 – 8.5 While alkali soils 2. Saline-Sodic soils EC > 4 ds/m pH < 8.5 Controlled by salts and time pH > 8.5 White alkali 1. Saline ( Non-saline soils) EC < 4 ds/m SAR > 15 PH > 9.5 Poor physical condition Worst soil pH = 8.2 – 8.5 Black alkali soils

5. Figure Different soils found in the Tadla agricultural perimeter including (a) saline-sodic soils; (b) saline deposit on stream bed; (c) sodic soil; (d) non-contaminated soil with a very good structure.  

6. Salt tolerance mechanism * Salinity tolerance comes from genes that limit the rate of salt uptake from the soil and the transport of salt throughout the plant, adjust the ionic and osmotic balance of cells in roots and shoots .

7. Tolerant Moderately Tolerant Barley Cotton Sugar beet Wheatgrass Date palm White olive Soyabean Pine apple Sudan grass Sweet clover

8. H alophytes are those plants which exhibit maximal relative growth under some salinity in the substrate. Although the growth in halophytes is enhanced by salinity in contrast to non-halophytes . Example: Halophytes

9. Plant can survive Moderate Salinity S maller and darker blue-green in colour than the normal leaves. Increased succulence due to the concentration of chloride ions in the soil solution is high. S ame appearance as plants growing under moisture stress conditions. Figure : Leaves of up land cotton Gossypium hirsutum

10. Plants in field conditions: Spotty growth of crops and often by the presence of white salt crusts on the surface. If the salinity level is not sufficiently high to cause barren spots, the crop appearance may be irregular in vegetative vigour. Figure. A saline patch of soil in a wheat field clearly hinders plant growth.

11. Reclamation and management practices

12. 1. Salt leaching A. Scraping Removing the salts that have accumulated on the soil surface by mechanical means. 1.Physical methods

13. Cont… B. Flushing   Washing away the surface accumulated salts by flushing water over the surface is sometimes used to desalinize soils having surface salt crusts.

14. 2. Drainage Recharge rates in Irrigation areas can be much higher than dryland areas due to leakage from both rainfall and irrigation. This causes potentially very high salinisation rates.

15. Types 1.Surface drainage D itches are provided so that excess water will run off before it enters the soil. Field ditches empty into collecting ditches built to follow a natural water course.

16. S ubsurface drainage is insufficient to carry the excess water and dissolved salts away from an area without the groundwater I t may be necessary to install an artificial drainage system. 2.Sub-surface drainage

17. 2. Chemical Method 1. Gypsum ( Sodic and Saline-sodic) It improves B ulk density A ggregate stability Water infiltration Chemical characteristics B iomass Crops production

18. 2. Corn stalk

19. 3. Biological Methods 1.Flooding Rising flood waters can cause the top of the soil to crust or a fine layer of clay to be deposited,  which may prevent oxygen and water penetration.

20. 2. Organic matter

21. Soil salinity problem in Pakistan Excessive salt rates are adversely influencing the biological, chemical, and physical properties of soils. Improper irrigation practices and lack of drainage are harmful to the crops. 14 % of irrigated lands have detetrioted with salinity. 64 % yield loses with salinity. 0.45 million hectares present in Punjab , 0.94 million hectares in Sindh and 0.5 million hectares in NWFP.

22. Conclusio n There are several methods to reclaim a salt-affected soil. Salt leaching and irrigation is the most important method among the aforementioned strategies. Its efficacy depends on soil physico-chemical conditions and climatic conditions of the site. R eclamation of salt-affected land should rely more on modelling techniques to increase the likelihood of reclamation success.

23. References Debez, A.; Huchzermeyer, B.; Abdelly, C.; Koyro, H.W. Current challenges and future opportunities for a sustainable utilization of halophytes. In Sabkha Ecosystems; Öztürk, M., Böer, B., Barth, H.J., Clüsener-Godt, M., Khan, M.A., Breckle, S.W., Eds.; Springer: Amsterdam, The Netherlands, 2010; Volume 46, pp. 59–77 Szabolcs, I. Soil and salination. In Hand Book of Plant and Crop Stress; Pessarakli, M., Ed.; Marcel, Dekker: New York, NY, USA, 1994; pp. 3–11.  Etesami H, Beattie GA. Mining halophytes for plant growth-promoting halotolerant bacteria to enhance the salinity tolerance of non-halophytic crops. Frontiers in Microbiology. 2018;9:148-167. DOI: 10.3389/fmicb.2018.00148 Corwin, D. L. (2021). Climate change impacts on soil salinity in agricultural areas. European Journal of Soil Science, 72(2), 842-862. Phogat, V., Mallants, D., Cox, J. W., Šimůnek, J., Oliver, D. P., & Awad, J. (2020). Management of soil salinity associated with irrigation of protected crops. Agricultural Water Management, 227, 105845.

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