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Abstract Plant-based agricultural systems rely heavily on inorganic nitrogen (N) fertilizers to increase yields and ensure food security for the rapidly growing global population. However, the production and overuse of synthetic fertilizers lead to significant amounts of greenhouse gas emissions, causing a critical need for the development of alternative and sustainable organic N fertilizers. Here, we demonstrate the effective use of lysed and dried bacterial biomass from the marine purple photosynthetic bacterium Rhodovulum sulfidophilum as an alternative source of N fertilizer for the cultivation of Japanese mustard spinach (komatsuna, Brassica rapa var. perviridis). To assess the suitability of this processed bacterial biomass, containing approximately 11% N, as a N fertilizer, we examined the effects of its application on plant germination and growth (measured by leaf chlorophyll, maximum leaf length, and dry weight) under two different temperature regimes, comparing it to that of a conventional N-containing mineral fertilizer. Application at rates up to four times that of the mineral fertilizer had no negative effects on seed germination and plant growth. The bacterial biomass had to be applied at approximately twice the rate of mineral fertilizer to obtain similar plant growth parameters, roughly corresponding to the predicted 62% rate of mineralization of the bacterial N. Our findings confirm the ability of plants to take up N from the lysed and dried biomass of marine purple photosynthetic bacteria, demonstrating the potential for using R. sulfidophilum as a source of N fertilizer.

Farm households along the coastlines of Myanmar and Vietnam are becoming increasingly vulnerable to flooding, saltwater intrusion, and rising sea levels. There is little information available on the relative vulnerability of men- and women-headed households, and the governments of Myanmar and Vietnam have not identified or implemented any adaptive measures aimed specifically at vulnerable peoples. This study aims to fill these gaps and assess the relative climate change vulnerability of men- and women-headed farm households. This study considers 599 farm households from two regions of Myanmar and 300 households from Thua Thien Hue province of Vietnam for the period 2021–2022. We offer a livelihood vulnerability index (LVI) analysis of men- and women-headed farm households using 46 indicators arranged into seven major components. The aggregate LVI scores indicate that farm households in Myanmar are more vulnerable (scores of 0.459 for men and 0.476 for women) to climate-related natural disasters than farm households in Vietnam (scores of 0.288 for men and 0.292 for women), regardless of the gender of the head of household. Total vulnerability indexing scores indicate that women-headed households are more vulnerable than men-headed households in both countries. Poor adaptive capacity and highly sensitive LVI dimensional scores explain the greater vulnerability of women-headed farm households. The findings also highlight the importance of the adaptive capacity components reflected in the LVI analysis in reducing farm households’ vulnerability.