Soil salinity and its associated effects on soil microorganisms, greenhouse gas emissions, crop yield, biodiversity and desertification: A review

Significant research has been conducted on the effects of soil salinity issue on agricultural productivity. However, limited consideration has been given to its critical effects on soil biogeochemistry (e.g., soil microorganisms, soil organic carbon and greenhouse gas (GHG) emissions), land desertification, and biodiversity loss. This article is based on synthesis of information in 238 articles published between 1989 and 2022 on these effects of soil salinity. Principal findings are as follows: (1) salinity affects microbial community composition and soil enzyme activities due to changes in osmotic pressure and ion effects; (2) soil salinity reduces soil organic carbon (SOC) content and alters GHG emissions, which is a serious issue under intensifying agriculture and global warming scenarios; (3) soil salinity can reduce crop yield up to 58 %; (4) soil salinity, even at low levels, can cause profound alteration in soil biodiversity; (5) due to severe soil salinity, some soils are reaching critical desertification status; (6) innovate mitigation strategies of soil salinity need to be approached in a way that should support the United Nations Sustainable Development Goals (UN-SDGs). Knowledge gaps still exist mainly in the effects of salinity especially, responses of GHG emissions and biodiversity. Previous experiences quantifying soil salinity effects remained small-scale, and inappropriate research methods were sometimes applied for investigating soil salinity effects. Therefore, further studies are urgently required to improve our understanding on the effects of salinity, address salinity effects in larger-scale, and develop innovative research methods.

Automated summary

Although significant research has been conducted on the effects of soil salinity issue on agricultural productivity, limited consideration has been given to its critical effects on soil biogeochemistry, land desertification, and biodiversity loss. This article synthesizes information from 238 articles published between 1989 and 2022 and highlights the impact of soil salinity on microbial community composition, soil organic carbon content, greenhouse gas emissions, crop yield, soil biodiversity, and desertification. The study emphasizes the need for innovative mitigation strategies that align with the United Nations Sustainable Development Goals and calls for further research to address knowledge gaps and improve understanding of salinity effects.