RESEARCH ARTICLE Halophyte residue decomposition and microbial community structure in coastal soil Doongar R. Chaudhary | Aditya P. Rathore | Bhavanath Jha Marine Biotechnology and Ecology Division, CSIR ‐ Central Salt and Marine Chemicals Research Institute, Bhavnagar 364 002, India Correspondence D. R. Chaudhary and Bhavanath Jha, Marine Biotechnology and Ecology Division, CSIR ‐ Central Salt and Marine Chemicals Research Institute, Bhavnagar, Gujarat 364 002, India. Email: drchaudhary@csmcri.res.in; bjha@csmcri.res.in Funding information Council of Scientific and Industrial Research (CSIR), Grant/Award Number: BSC0117‐PMSI and BSC0109‐SIMPLE Abstract Saltmarshes are known for higher primary productivity and play a crucial role in carbon‐sequestration, nutrient‐cycling, and ecological services; however, scarce infor- mation are available on halophyte residue mineralization and microbial community structure during decomposition. Soil microcosms with residues (1% w/w) of three dominant halophytes (Aeluropus lagopoides, Arthrocnemum indicum, and Suaeda nudiflora) and one control were incubated under laboratory conditions and sampled at 1, 5, 10, 20, 40, and 90 days to link the microbial community structure and residues decomposition in degraded coastal soil. Samples were subjected to identification of active microbial groups and residue mineralization using fatty acid methyl ester (FAME) and CO 2 evolution methods, respectively. Biochemical composition of resi- dues was also analyzed. Cumulative CO 2 evolution was elevated in residue‐ amended soils compared with control, and it was highest in Arthrocnemum followed by Suaeda, Aeluropus, and control soil. The Aeluropus residue decomposed slower than others due to its high C/N ratio and low protein content. The contents of total FAME and biomarker FAMEs of microbial groups (bacterial, fungal, and actinomycetes) responded positively to the residue amendments compared with control, which indi- cate the improvement in soil microbial biomass. Soils amended with Suaeda had the highest amount of total (76.8 nmol/g) and fungal FAMEs (6.7 nmol/g), and bacterial (28.6 nmol/g) and actinomycete (3.0 nmol/g) FAMEs were elevated in Arthrocnemum amended soil. At the same time, soils amended with Suaeda (6.2%), Arthrocnemum (28.4%), and control (15.4%) had the greatest abundance of fungal, Gram‐negative and Gram‐positive FAME biomarkers, respectively. The present study suggests that residue of halophyte species affected the abundance of fungal and bacterial biomarkers, and the microbial community structure. KEYWORDS FAME, halophytes, microbial community, mineralization, saltmarsh 1 | INTRODUCTION Soil salinization is a severe problem of soil degradation, which adversely affects the biological, chemical, and physical characteristics (Fan et al., 2012; Ivits, Cherlet, Tóth, Lewińska, & Tóth, 2013; Paix et al., 2013; Singh, 2009). Halophytic plants are capable of growing under high soil salinity. Saltmarshes are the most productive ecosys- tem with higher primary productivity and carbon (C) sequestration potential (Bouchard & Lefeuvre, 2000; Glenn, Pitelka, & Olsen, 1992). Halophytes have potential to be an economically viable crop, which are cultivable on nonagricultural lands under seawater irrigation (Glenn et al., 1992; Nikalje, Srivastava, Pandey, & Suprasanna, 2018; Received: 31 July 2018 Revised: 18 April 2019 Accepted: 29 April 2019 DOI: 10.1002/ldr.3335 Land Degrad Dev. 2019;1–11. © 2019 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/ldr 1