## 1 Introduction  
Approximately one billion hectares of land worldwide are affected to varying degrees by salinity and related threats. The increasing demand for the expansion of intensive irrigated agriculture, rising temperatures, more frequent droughts, and water scarcity have led to the accumulation of salts in soils irrigated with saline water. These conditionsexacerbate salinization, sodication, and high sodium adsorption ratios (SARs), degrading the chemical environment and the physical health of soils [1]. Salinity adversely affects crop growth and yield, posing serious challenges to food security and economic stability in affected regions [2; 3]. Numerous studies have demonstrated the detrimental effects of salinity on crop productivity. For example, maize grain yield has been reported to decline by up to 34% when soil salinity increases from 3.8 to 7.4 dS m\({}^{-1}\)[4]. Additionally, crop yields generally decrease in proportion to rising soil electrical conductivity (EC), with estimated reductions of 10% at 2.5 dS m\({}^{-1}\), 25% at 3.8 dS m\({}^{-1}\), 50% at 5.9 dS m\({}^{-1}\), and 100% at 10 dS m\({}^{-1}\)[5]. In Peru, salinization has been reported on approximately 300,000 hectares of irrigated land, with nearly 150,000 hectares exhibiting high salinity levels. It is estimated that around 40% of the total agricultural area along the Peruvian coast is affected by soil salinity [6]. The strategies for managing saline soils include deep plowing or subsoiling, profile washing, calcium salts, acids, acidifying salts, and the addition of organic amendments [7]. More sophisticated methods, such as drip irrigation, are extensively encouraged in Peru due to their water-saving benefits and effectiveness in reducing soil salinity. This approach supplies water straight to the root zone, which helps limit evaporation and prevents salt from accumulating on the surface [8]. In this context, there is a need to develop sustainable agricultural practices that can improve soil quality in saline environments while contributing to circular economy models. Among such practices, the use of biochar, a stable, carbon-rich byproduct from pyrolysis, has gained attention for its capacity to improve soil health and mitigate environmental stress. Biochar has demonstrated residual effects in reducing sodium (Na\({}^{+}\)) uptake under saline stress conditions, through mechanisms such as Na\({}^{+}\) sorption, increased soil moisture retention, and the supply of essential nutrients that could reduce Na\({}^{+}\) uptake by plants [9]. Additionally, its alkaline nature, structural stability, and potential to sequester carbon make it a promising tool for improving agricultural productivity, reducing greenhouse gas (GHG) emissions, and promoting soil regeneration [10]. Similarly, previous studies had mentioned that vermicompost and organic amendments are a cost-effective and sustainable approach to improving soil quality in salt-affected regions and boosting crop yields in areas with severe salinity issues [11; 12]. Also, vermicompost is rich in essential nutrients, humic acids, growth-regulating hormones, and enzymes, enhancing plant nutrition, boosting photosynthesis, improving overall crop quality, and offering potential benefits for pest control [13]. In this sense, vermicompost leachate (or \"vermiwash\") has demonstrated noticeable effects on plants and soil. It was found to possess properties that function as a liquid organic biofertilizer and a biopesticide [14]. Both amendments originate from agricultural residues, aligning with the principles of circular agriculture by promoting resource efficiency, reducing waste, and enhancing soil resilience. Nevertheless, despite their benefits, knowledge gaps remain regarding the comparative performance of biochar and vermicompost leachate under salinity stress conditions, especially in coastal agroecosystems. Moreover, potential limitations have been reported.