European Journal of Sustainable Agroecosystems

Background: Sesbania aculeata is a species of tree native to Africa and Asia commonly known as dhaincha or jantar. Due to its quick growth and ability to fix nitrogen biologically, Sesbania aculeata is crucial in crop rotations, especially in rice agriculture. Moreover, as prices of synthetic nitrogen fertilizers are increasing, the interest in the utilization of Sesbania aculeata is growing. The goal of the paper is to perform a literature review on the Sesbania aculeata's impact on biomass and nitrogen accumulation, its role as a nitrogen fertilizer substitute, the effectiveness of its utilization as a nitrogen resource, and on the yield of crops cultivated in rice-wheat, rice-rice and other cereal regimes.
Sources of literature: Evidence was drawn from Scopus, Web of Science, ScienceDirect, SpringerLink (Plant and Soil, Nutrient Cycling in Agroecosystems), PubMed Central, and regional agronomy journals, supplemented by AICRP-IFS and ICAR institutional reports, using keywords including “Sesbania aculeata,” “dhaincha,” “green manuring,” “nitrogen economy,” “nitrogen substitution,” and “rice-wheat cropping system.”
Key observations: Sesbania aculeata is shown to normally accumulate a high biomass (4.6-6 t ha -1 dry mass; up to 23 t ha 1 green mass) and fix 100-131 kg N ha -1, with biological nitrogen fixation accounting for 77-82 % of the total nitrogen in the plant, when grown for 45-60 days during the pre-rice or summer fallow period. The immediate rice crop used 43-122 kg urea-N ha -1 instead. The residual benefit in the following wheat crop was equivalent to 27-89 kg urea-N ha -1. The long-term integrated trials have shown the ability of Sesbania to maintain nitrogen-use efficiency gains and yields with 50% of the initial fertilizers used. Nevertheless, this conclusion is influenced by the age of the green manure used, the soil type, the greenhouse decomposition duration prior to transplanting, type of soil (the effectiveness of Sesbania green manure is lower in calcareous and some alkaline soils), the relative effectiveness of different traditional green manures and grain legumes as it has been shown in various studies.
Research gaps: There is still a lack of certain research areas such as the standardized reporting of biological nitrogen fixation efficiency, the evolution of soil nitrogen stocks over multi-decadal periods, farmers’ constraints in adopting new practices, and a relative economic analysis of this strategy against various nitrogen management alternatives.
Conclusion: Sesbania aculeata green manuring appears to be a proved method of increasing nitrogen performance in cereal-based cropping systems that can replace a significant share of fertilizer nitrogen. It should be kept in mind, though, that its implementation and efficacy depend on multiple factors such as soil type, degradation treatment, and other land use constraints available at the time of implementation of this measure.