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New Blog from ISSM4RICE project: Tackling soil salinity – The role of soil management

30-12-2024


Crop and soil management are key in the fight for soil salinization mitigation. Adding soil organic matter improves the structure of the soil and flushes salts from it. A higher content in organic matter leads to an improved water-holding capacity of the soil, which decreases the concentration of soluble salts instead of accumulating them in the root zone. Organic matter also contributes to the formation of soil aggregates, creating pores that allow for air and water movements in the soil. As a result, excessive salts are taken away from the root zone and leached deeper in the soil profile.
  • The incorporation of straw can be a significant way to increase the soil organic matter content. Straw incorporation techniques encompass ploughing, disking, or harrowing. Mulching or conservation tillage practices that leave the straw on the soil surface are also recommended.
  • Soil cover or mulching plays an important role in addressing soil salinity by protecting the soil surface from direct evaporation and it reduces salt accumulation close to root zone. However, one must be aware that straw quality and quantity influence the effectiveness of this mitigation measure. Aside from increasing methane emissions, slow straw decomposition in fields or excessive residues hinders the crop germination and development (Ma et al., 2008; Su et al., 2014).
  • To counter adverse effects straw incorporation could bring to the crops, the use of organic fertilizers allows for building soil organic carbon levels in a similar mitigation strategy. Organic fertilizers are derived from natural sources, such as animal manure, compost or cover crops. The carbon source offered by organic matter to the soil also stimulates the activity of microorganisms that decompose organic materials. As a result, essential nutrients for plant growth are released gradually, supporting nutrient cycling and availability in the soil. Efficient nutrient management supports balanced soil ecosystems and prevents the accumulation of salts.
  • In a study conducted by Sudratt & Faiyue (2023), rice husk biochar amendment had a positive effect on the growth and yield of rice plants growing in soil subject to saltwater intrusion at the seedling stage. Biochar mitigated the adverse effects of saline water intrusion by absorbing Na+ ions in the soil, reducing Na+ uptake to the shoot and increasing the K+/Na+ ratio (Sudratt & Faiyue, 2023).
Learn more about the role of soil management in tackling soil salinity here
 

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