An approach toward sustainable use of coastal saline soils vis-a-vis the performance of spinach: An in situ study

Coastal regions characterized by different degrees of soil salinity pose a significant challenge to agricultural productivity. This study investigates an approach for the sustainable use of coastal saline soils, focusing on the cultivation of spinach (Spinacia oleracea L.) as a test crop. Through in situ experimentation in the south-eastern coastal part of Bangladesh, we analyzed soil amendment techniques and the resilience of spinach in terms of yield and nutritional quality in a moderately saline soil. The present experiment consists of four treatments viz. un-amended (T1), only N-P-K dose (T2), vermicompost (VC) at 1% (w/w) with N-P-K (T3), VC plus wood ash (WA) at 1% (w/w) of each (T4). Biomass and dry matter were found in the following sequence T3>T4>T2>T1. The uptake of macronutrients and micronutrients grown in treated soils significantly (p<0.05) increased over control with the highest response in VC amended soils followed by VC plus WA application. The tolerance of spinach to salinity was found to be highest in VC amended soils and minimum in control. Analyses of the soils after harvest of spinach revealed that the availability of all nutrients except Fe and Mn increased in VC plus WA treated condition. The single application of organic amendment (i.e., VC) is recommended for better performance of spinach in soils with neutral (pH 6.75) soil reaction and moderate salinity. The results suggest that proper soil management can enhance productivity, offering a sustainable pathway for coastal agriculture.