Browsing by Author "Tarit Roychowdhury"

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Combined effects of dry-wet irrigation, redox changes and microbial diversity on soil nutrient bioavailability in the rice field
(Elsevier B.V., 2023) Arnab Majumdar; Pradeep Kumar Dubey; Biswajit Giri; Debojyoti Moulick; Ashish Kumar Srivastava; Tarit Roychowdhury; Sutapa Bose; Manoj Kumar Jaiswal
Sustainable development goals (SDGs) by United Nations are some of the high-priority areas of research and this article established the sustainable agronomic practices converging soil chemistry, crop productivity and soil microbial involvement in nutrient modulation. Alternate wetting-drying (AWD) cultivation with implications on soil microbiome, nutritional dynamics and rice yield during pre-monsoon (boro) and monsoon (aman) season are not well studied. In the present 4-year field study, the impact of AWD irrigation in pre-monsoon and flooded irrigation in monsoon on soil microbiota and the nutrient pool has been studied. Nutrient-less pond water has been used to avoid any external nutrient input from irrigation water to ensure the sole elemental flux within the soil itself. The release of soil nutrients into the soil-aqueous system, influencing microbial populations and modulating the redox status was explored. Results indicated an increase in total concentration as well as bioavailability of selected nutritional elements (N, P, K, Fe, Ca, Mg, Cu and Zn) by 16–54% in the pre-monsoon cultivation relative to monsoon cultivation. Three plant growth phases (developing, milking and harvest) were considered to check the nutrient modulations in soil and plant tissues along with the plant growth and elemental uptake continuum. Crop plant measurements were improved and grain yields were found to be 5.2–6.46% increased under AWD and microbial activity. Krona charts, relative abundance, rarefaction curve and multivariate analysis of metagenomics data showed that the pre-monsoon soil was more enriched and maintained a balance between soil pH and microbial biomass than the monsoon soil. Microbial community diversity associated with plant growth phases was also found to be different depending on the seasonal alterations. Bacillus sp., Acidothiobacillus sp., Pseudomonas sp., Rhizobium sp., Burkholderia sp. were predominant in pre-monsoon soil releasing pulses of N, P, K, Ca and Mg whereas Verrucomicrobia was found to be dominant in monsoon soil where Fe was released. This study is a first of its kind that showed the combined effect of season and some specific groups of soil microbes on macro-micro nutritional availability in soil and enhanced plant quality. © 2023 Elsevier B.V.
Involvement of soil parameters and rhizosphere microbiome in sustainable crop productivity
(Elsevier, 2024) Shreyosi Dey; Arnab Majumdar; Pradeep Kumar Dubey; Tarit Roychowdhury; Jayjit Majumdar; Subhas Chandra Santra; Akbar Hossain; Debojyoti Moulick
Sustainable development goals by the United Nations promote global crop productivity and crop quality maintenance to minimize the food crisis. Crop cultivation might vary region-wise although rhizospheric soil microbiome similarly plays a critical and inductive role in crop productivity globally. Plant growth-promoting rhizobacteria and arbuscular mycorrhiza (AM) are some of the best crop quality inducers followed by macro/microalgae and other fungi. Crop plants are known to regulate various secondary metabolites, root exudates and mineralogical conversions where these microbes are involved inevitably. Rhizospheric microbes can certainly control other pathogenic microbial colonization and crop pathogen manifestations. These combined effects exert a positive impact on the associated crop health and productivity. Soil physiochemical parameters, abiotic stresses and nutrient deficiencies are well-managed within the rhizospheric microbiome. Crop growth-promoting microbes are also known to trigger plant tolerance mechanisms allowing better crop health. Plant microbial symbiosis can elucidate this insight using a nodular and nonnodular crop plant. So, a better crop yield and quality maintenance should involve a rhizospheric microbiome dealing with multiple sustainable applications. © 2025 Elsevier Inc. All rights reserved.
Sustainable water management in rice cultivation reduces arsenic contamination, increases productivity, microbial molecular response, and profitability
(Elsevier B.V., 2024) Arnab Majumdar; Munish Kumar Upadhyay; Biswajit Giri; Poonam Yadav; Debojyoti Moulick; Sukamal Sarkar; Barun Kumar Thakur; Kashinath Sahu; Ashish Kumar Srivastava; Martin Buck; Mark Tibbett; Manoj Kumar Jaiswal; Tarit Roychowdhury
Arsenic (As) and silicon (Si) are two structurally competitive natural elements where Si minimises As accumulation in rice plants, and based on this two-year field trial, the study proposes adopting alternating wetting and drying (AWD) irrigation as a sustainable water management strategy allowing greater Si availability. This field-based project is the first report on AWD's impact on As-Si distribution in fluvio-alluvial soils of the entire Ganga valley (24 study sites, six divisions), seasonal variance (pre-monsoon and monsoon), rice plant anatomy and productivity, soil microbial diversity, microbial gene ontology profiling and associated metabolic pathways. Under AWD to flooded and pre-monsoon to monsoon cultivations, respectively, greater Si availability was achieved and As-bioavailability was reduced by 8.7 ± 0.01–9.2 ± 0.02% and 25.7 ± 0.09–26.1 ± 0.01%. In the pre-monsoon and monsoon seasons, the physiological betterment of rice plants led to the high rice grain yield under AWD improved by 8.4 ± 0.07% and 10.0 ± 0.07%, proving the economic profitability. Compared to waterlogging, AWD evidences as an optimal soil condition for supporting soil microbial communities in rice fields, allowing diverse metabolic activities, including As-resistance, and active expression of As-responsive genes and gene products. Greater expressions of gene ontological terms and complex biochemical networking related to As metabolism under AWD proved better cellular, genetic and environmental responsiveness in microbial communities. Finally, by implementing AWD, groundwater usage can be reduced, lowering the cost of pumping and field management and generating an economic profit for farmers. These combined assessments prove the acceptability of AWD for the establishment of multiple sustainable development goals (SDGs). © 2024 Elsevier B.V.