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Saline‐alkali soils cover an area of more than 900 million ha and pose an acute threat to global food security. Rice cultivation is an effective method of saline‐sodic soil amelioration in the Songnen Plain in northeastern China. However, the changes in soil microbial communities that follow rice cultivation are largely unknown. In this study, soil bacterial and fungal communities were investigated using high‐throughput sequencing along a chronosequence of rice paddies cultivated in saline‐sodic soils. The results showed that soil fungi and bacteria become more diverse and abundant after rice cultivation compared with uncultivated saline‐sodic soil, in combination with the decreased pH and increased soil organic matter, indicating the amelioration of saline‐sodic soil. The processes of microbial succession following rice cultivation can be divided into two stages: shorter than and longer than 10 years. Moreover, soil fungi and bacteria exhibited distinct variation patterns as they were dominated by different influential factors. The results indicated that bacteria were more strongly dominated by soil properties than fungi, while the latter were more dependent on vegetation. As rice cultivation continued, fungi exhibited better adaptation and faster succession than bacteria in response to environmental shifts after rice cultivation. Therefore, measures that can enhance plant–microbe interactions may be a viable approach for promoting saline‐sodic soil amelioration. This study provided novel insights into the microbial assembly processes following rice cultivation on saline‐sodic lands. [ABSTRACT FROM AUTHOR]

Drought seriously endangers the development of agro‐pastoral ecotone in arid and semi‐arid regions. However, drought evolution characteristics of semi‐arid sandy grassland and its drivers are not well understood in the complex climate change context. Thus, in this paper, the revised standardized precipitation evaporation indices on one‐month (SPEI‐1) and growing‐season (SPEI‐6) scale, flash drought and dry spells (DS) were calculated as drought indicators, and the temporal variabilities and meteorological drivers of drought in Horqin Sandy Land during the growing period (April–September) from 2007 to 2021 were studied. The results showed that SPEI‐1 and SPEI‐6 exhibited negative trends and periodic change. This drought aggravation was manifested in increased grades and numbers of drought months. Flash droughts can occur every month during the growing season. And its occurrence was not only positively correlated with all drought events in frequency but also synchronized in time. The increased number of DS showed an asymmetrical shift towards 7‐day‐and‐longer DS. SPEI sensitivity to precipitation (P) was noticeably higher than to atmospheric evapotranspiration demand (AED) at both monthly and growing season scales. SPEI sensitivity to AED was modulated by P amounts, which was higher during low P period. Apart from the amounts of P and AED, their temporal variability also strongly determined how they affect the drought severity. P was also the main driver for flash drought and long DS, but AED with larger amount and higher variability is the reason for their aggravation. Our results demonstrate the complexity of drought intensification in semi‐arid sandy grasslands and highlight the important role of AED anomalies in it. [ABSTRACT FROM AUTHOR]