Land use change has been one of the common problems in the context of urbanization in China. Social economy and land use interact with each other, and it is especially important for human society to adhere to sustainable development, and to deal with the contradictory relationship between the social–economic needs and land use change. The objectives of this study are: (1) Obtain time-series land-use classification data and its spatial distribution in Nanchang City; (2) Identify the characteristics and driving force of spatial–temporal land use changes in Nanchang City from 2000 to 2020; (3) Discuss the relationship between the urban expansion and social economy in Nanchang City. The results show that the spatial distribution of land use in Nanchang City has changed significantly from 2000 to 2020, and the largest area of land-use type in Nanchang City has been cropland. The cropland has continuously declined, and the urban area has increased significantly. A lot of cropland has been transformed into urban areas, and land use degree in Nanchang City has significantly increased. The spatial pattern of land use has greatly changed, and the city spatial pattern has become more aggregated, while the spatial distribution of cropland, forest and grassland has become more fragmented. Moreover, there has been an obvious correlation between social-economic development and the level of land use, and GDP has been the main driver of land use change. The central urban area of Nanchang city has been the main hotspot of land use change.

With an ageing population, promoting physical activity in community parks is crucial for healthy urban living. This study examines the spatial preferences and environmental determinants of physical activity among senior citizens in four high-density community parks in Nanchang, China. Using the System for Observing Play and Recreation in Communities, 32 full-day observations were conducted across 121 micro-spatial units. Global Moran’s I tests confirmed that sedentary behaviour exhibited significant spatial clustering (I = 0.137, Z = 2.65, p < 0.01), while moderate-to-vigorous physical activity followed a random distribution pattern. Principal Component Analysis and hierarchical clustering identified 14 distinct spatial typologies. Stepwise multiple linear regression models revealed that: (1) sedentary behaviour is decisively and solely driven by the provision of rest facilities (PC4, β = 0.310, p = 0.001), outweighing landscape aesthetics or spatial enclosure; and (2) no significant environmental predictors were identified for moderate-to-vigorous physical activity, suggesting it is more influenced by social organisation than micro-environmental features. These findings offer a fine-grained spatial diagnostic framework, advocating for a "functionality-first" design strategy. The study suggests that precision placement of rest nodes, rather than general landscape enhancement, is critical for supporting the stationary engagement and diverse behavioural rhythms (e.g., stationary socialisers, casual movers and vigorous participants) of ageing populations.

Acidic soils are widespread in global agroforestry systems and severely constrain crop production through proton stress, aluminum/manganese phytotoxicity, phosphorus fixation, and rhizosphere microbiome reassembly. Rhizosphere diazotrophs can theoretically contribute to plant nitrogen (N) nutrition and stress adaptation. However, their N-fixation efficiency and growth-promoting effects in acidic soils are often highly unstable, limiting the predictability of field applications. This narrative mechanistic review synthesizes and critically interprets evidence on the physicochemical filters governing diazotroph survival in acidic soils, nitrogenase regulation, root-exudate-mediated recruitment, multi-guild microbial interactions, and the conditional design of synthetic microbial communities (SynComs) and inoculant formulations. We further discuss the potential complementary roles of phosphate-solubilizing bacteria (PSB) and arbuscular mycorrhizal fungi (AMF) and propose minimum reporting standards to improve field translatability. The synthesis indicates that effective diazotroph-mediated crop promotion depends on pH buffering, metal detoxification, carbon supply, phosphorus availability, host compatibility, and native microbiome receptivity. The proposed evidence-chain and microbiome-compatibility framework is a conceptual guide for evaluating these linked conditions rather than an empirically validated predictive model.