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Tillage and straw returning are promising practices to improve soil quality, especially because of the unclear controlling effects on microbial communities and functions. A 5‐year field experiment in a winter wheat‐summer maize cropping system was implemented in the North China Plain to address this research gap. Management practices were deep tillage, rotary tillage, and no‐tillage, each with either wheat only or both wheat and maize straw returning. Shotgun metagenomic sequencing was performed to investigate the microbial community, diversity, co‐occurrence network, and function in the topsoil (0–20 cm). The associations between soil physiochemical properties and microbial community characteristics were also evaluated. Rotary tillage with only wheat straw returning (RTS) significantly increased Shannon's diversity index by 0.24%–1.71% compared to other treatments. No‐tillage with only wheat straw returning (NTS) showed the most stable microbial network with the highest betweenness centrality (199.09), average path distance (2.31), and modularity (0.50). NTS had the highest relative abundance of microbial carbon (C), nitrogen (N) metabolisms, and C fixation pathways. Among deep tillage practices, both wheat and maize straw returning (DTD) were more beneficial to the stability of microbial networks than only wheat straw returning (DTS), yet without improvement in microbial diversity and function. In conclusion, microbial community and function are practical predictors of variations in soil nutrient availability, and pH value in response to different tillage and residue management practices. In particular, our study provides a basis for the development of a sustainable crop residue management system. [ABSTRACT FROM AUTHOR]

Intercropping, particularly within legume‐based systems, has been shown to enhance yields and optimize resource use efficiency. Yet, the potential contribution of intercropping on soil microbial communities and functions to soil nutrients cycling are not fully understood. We conducted the same field experiments at Youyu (Site1) and Zhangbei (Site2) in Northern China to evaluate the impact of oat/soybean intercropping on the rhizosphere soil bacterial community structure, composition, and co‐occurrence networks. Our results indicated that intercropping significantly modified the bacterial community structure for both oat and soybean at Site1, with changes observed only in the oat community at Site2. Specifically, intercropping led to a substantial increase in the relative abundance of Bacteroidetes and Patescibacteria in the oat rhizosphere by 48.3% and 65.4% (Site1), respectively. Conversely, in the soybean rhizosphere at Site1, there was a notable decrease in the abundance of Patescibacteria and Nitrospirae by 32.4% and 40.0%, respectively. The soil bacterial functional groups demonstrated robust positive correlations with key soil parameters such as available nitrogen (Nmin), available phosphorus (Avail‐P), and the activities of nitrogen‐ and phosphorus‐acquiring enzymes in the rhizosphere. In conclusion, intercropping is an effective agricultural practice for enhancing nitrogen and phosphorus cycling by reshaping the soil bacterial community, offering a distinct advantage over monoculture practices. This insight underscores the potential of intercropping to foster sustainable soil nutrient management, highlighting the importance of integrating such practices into modern agricultural strategies to ensure long‐term productivity and environmental sustainability. [ABSTRACT FROM AUTHOR]

Agricultural practices of nitrogen and irrigation overuse bring lots of environmental problems, such as greenhouse gases (GHGs) emissions, soil, and water pollution. With the fast expansion of saline and alkaline agricultural soils in the Tarim River Basin, field practice must be very cautious facing water limitations and global warming. The GHGs were measured 1–2 times weekly and water and fertilizer use efficiency were evaluated under five treatments: (1) fallow (Control); (2) no N (kg N ha−1) and no irrigation (mm) (0N0W); (3) 200 and 355 (LNLW); (4) 230 and 475 (MNMW), and (5) 320 and 655 (HNHW) (traditional treatment) from 2018 to 2019 under maize in Aksu in the Tarim River Basin. The GHGs increased with fertilization and irrigation. The cumulative GHGs were 0.6–5.9 Mg CO2–C ha−1, 0.2–3.6 kg N2O–N ha−1, and increased significantly with biomass increase. The cumulative CH4 was −0.03 to −0.12 kg C ha−1. The MNMW resulted in the highest average water use efficiency (27 kg ha−1 mm−1), irrigation water use efficiency (32 kg ha−1 mm−1), and agronomic N use efficiency (44 kg kg−1), but the lowest greenhouse gas intensity (0.4 kg CO2‐eq ha−1 grain yield). The MNMW reduced the average of 10 mm water, 5 kg N ha−1 fertilizer, and 4 × 10−3 kg CO2‐eq ha−1 GHGI earning 1 t ha−1 maize compared to HNHW. The CO2 emission had a strong relationship with temperature (T) and soil moisture (W) (CO2 emission = (exp (a + bW + cW2)) Q10(T‐20)/10)) (R2 = 0.59–0.92). The lowest was in the LNLW treatment in 2019; the highest was in the HNHW in 2018). The emission of CO2 responding to fertilization was below the global trend, but that of N2O was above under maize in saline and alkaline soils (pH 7–9). In conclusion, MNMW was the best field management to mitigate GHGs with the highest water and fertilizer use efficiency under maize in saline and alkaline soils in Tarim River Basin, where had the higher N2O emission risk. [ABSTRACT FROM AUTHOR]