Vermicompost and its role in alleviation of salt tress in plants - II. Impact of vermicompost on the physiological responses of salt-stressed plants

Vermicompost (VC) is the solid excreta of earthworms, produced through the metabolism of organic matter under aerobic conditions. Thus, vermicompost is a product of the biodegradation, non-thermophilic process of organic materials through interactions between microorganisms and earthworms. This odorless, light organic product of the vermicomposting process is casts, or castings that is rich in humus, large amounts of macro- and micro-elements. These properties will largely influence the penetration of plant roots, potential rooting volume, nutrient movement and uptake, water availability, and soil aeration. Soil texture is also a key factor in affecting moisture content of the soil and its chemical properties, such as its cation exchange capacity or the capability of the soil to hold positively charged ions. Therefore, the application of vermicompost to sandy soils is very beneficial, as they help increase the soil organic matter composition, which in turn aids in improving soil aeration, sustaining good soil aggregation, protecting against soil erosion, and increasing nutrient availability. Moreover, vermicompost contains various plant nutrients such as nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, zinc, copper, and boron that improve the nutrient content of different plant components such as roots, leaves, and fruits. There have been many studies on the application of various organic fertilizers to plants for alleviating the negative effects of salinity. This paper will cover the contribution of vermicompost as a biological fertilizer and its effects on soluble sugar and proline content, membrane stability, biochemical, physiological, and molecular factors to mitigate the negative effects of salinity.