Conservation tillage and fertilization are widely adopted in agricultural systems to enhance soil fertility and influence fungal communities, thereby improving agroecosystems. However, the effects of no-tillage combined with manure on grain yield, nitrogen use efficiency (NUE), soil fertility, and rhizosphere fungal communities remain poorly understood, particularly in rainfed wheat fields on the Loess Plateau. A 15-year field experiment was conducted at the Niujiawa Experimental Farm of the Cotton Research Institute, Shanxi Agricultural University. Five treatments were assessed: conventional tillage without fertilizer (C), no-tillage with chemical fertilizer (NT), no-tillage with chemical fertilizer and manure (NTM), conventional tillage with chemical fertilizer (T), and conventional tillage with chemical fertilizer and manure (TM). The results demonstrated that the NTM treatment significantly increased grain yield by 124.95%, NT by 65.88%, TM by 68.97%, and T by 41.75%, compared to the C treatment (p < 0.05). NUE in the NTM treatment was improved by 58.73%–200.59%. Compared with the C treatment, NTM significantly enhanced soil nutrients, including organic matter (OM) by 70.68%, total nitrogen (TN) by 8.81%, total phosphorus (TP) by 211.53%, available nitrogen (AN) by 90.00%, available phosphorus (AP) by 769.12%, and available potassium (AK) by 89.01%. Additionally, the NTM treatment altered the rhizosphere fungal community of winter wheat, with Ascomycota (81.36%–90.24%) being the dominant phylum, followed by Mucoromycota (5.40%–12.83%) and Basidiomycota (1.50%–8.53%). At the genus level, NTM significantly increased the abundance of Mortierella and Dendrostilbella. An α-diversity analysis revealed that the richness and diversity of soil fungi were highest under NTM. The unweighted pair-group method with arithmetic mean (UPGMA) and principal coordinates analysis (PCoA) based on Bray-Curtis distances indicated that NTM formed a distinct fungal community with the highest phylogenetic diversity, which differed significantly from other treatments. Redundancy analysis (RDA) demonstrated that soil chemical properties variably influenced fungal community dynamics, with higher abundances of Ascomycota and Zoopagomycota positively correlated with OM, AN, AP, TP, and AK. Correlation analysis showed that wheat yield and NUE were positively correlated with Mortierella and Dendrostilbella, and negatively correlated with Fusarium, Chaetomium, and Alternaria. In conclusion, no-tillage with manure not only enhanced soil fertility but also enhanced soil fungal community structure, leading to greater wheat yield and NUE. These findings provide guidance for agricultural practices in rainfed wheat fields of the Loess Plateau.

Straw incorporation and manure are recognized as a sustainable farming practice to enhance soil fertility and improve crop yields. However, the effects of straw incorporation in combination with manure on productivity, soil nutrient status, N use efficiency (NUE), and the bacterial community are not well understood in wheat–summer maize rotation systems in the southern Shanxi Province. The five treatments were (1) CK, no fertilization; (2) NP, inorganic N and P fertilizers; (3) NPM, mineral N and P fertilizers plus chicken manure; (4) SNP, mineral N and P fertilizers plus maize straw; and (5) SNPM, mineral N and P fertilizers plus maize straw and chicken manure. The results showed that NP, NPM, SNP, and SNPM significantly increased wheat yields by 56.19%, 76.89%, 111.08%, and 114.30%, compared with CK, respectively. Nitrogen agronomic efficiency (AE_N), partial factor productivity (PEP_N), apparent recovery efficiency (Apparent RE_N), and accumulated recovery efficiency (Accumulated RE_N) increased by 103.36%, 37.19%, 76.39%, and 30.90% in the SNPM treatment, compared with NP. Straw incorporation and manure significantly improved soil fertility. Proteobacteria, Acidobacteriota, Actinobacteriota, Chloroflex, Bacteroidota, Planctomycetota, Gemmatimonadota, Armatimonadota, Firmicutes, Methylomirabilota, and Myxococcota were the predominant bacterial phyla. Compared with NP, straw incorporation and manure (NPM, SNP, and SNPM) decreased diversities (richness index, Chao1 index, and Shannon index). Principal coordinates (PCoA) and cluster analyses demonstrated that manure treatments (NPM and SNPM) significantly optimized bacterial community structure. Pearson’s correlation analysis demonstrated that organic matter, total phosphorus, available nitrogen, available phosphorus, and available potassium had significant positive correlations with Halanaerobiaeota but significant negative positive correlations with Chloroflexi, Entotheonellaeota, and Myxococcota. Wheat yields, AE_N, PEP_N, Apparent RE_N, and Accumulated RE_N were primarily and significantly negatively associated with Cyanobacteria. Straw incorporation in combination with manure significantly optimized bacterial community structure, wheat yields, and N use efficiency through improving soil fertility. Collectively, straw incorporation in combination with manure is a promising practice for sustainable development.

To avoid continuous cropping problems with Bupleurum, we screened suitable preceding crops for rotation with Bupleurum through different crop rotations. Therefore, the objective of this study was to find out the relationships between microbial community characteristics, soil properties, and enzyme activities under four different rotation patterns, including fallow-Bupleurum (CK), maize-Bupleurum (M), soybean-Bupleurum (So), and sunflower-Bupleurum (Su). Results indicated that under all four rotation patterns, So treatment significantly enhanced soil nutrients and enzyme activities compared to CK. So not only optimized the composition of soil bacterial and fungal communities but markedly enhanced microbial α diversity. Additionally, So exhibited high similarity in bacterial and fungal community composition with M, and featured complex symbiotic relationships within the soil microbial network. While no clear discrepancies were detected in the abundance of the top twenty metabolic pathways in the predictive functions of bacterial and fungal communities across four rotation patterns, the metabolic pathway function MET-SAM-PWY (methionine synthesis pathway) in bacterial communities and the metabolic pathway function VALSYN-PWY (valine synthesis pathway) in fungal communities were particularly prominent under the So rotation pattern. RDA suggested that soil properties (available phosphorus and pH) and enzyme activities (sucrase and alkaline phosphatase activities) were the driving forces for bacterial community composition, while soil properties (soil organic matter and available potassium) and enzyme activities (sucrase and catalase activities) regulated fungal community composition. Hence, the soybean-Bupleurum rotation pattern represents a cultivation practice more beneficial for the sustainable development of the bupleurum industry, which can significantly improve soil fertility and the micro-ecological environment.