Crop rotation and diversification (CRD) are crucial strategies in sustainable agriculture, offering multiple benefits to both farmers and the environment. By alternating crops or introducing diverse plant species, CRD practices improve soil fertility, reduce pest populations, and enhance nutrient availability. For example, legume-based rotations increase soil nitrogen levels through biological nitrogen fixation, reducing the need for synthetic fertilizers. Moreover, these practices promote more efficient water and nutrient use, reducing the reliance on synthetic fertilizers and minimizing the risk of pests and diseases. This review synthesizes findings from recent research on the role of CRD in enhancing sustainable agriculture and resilience, highlighting the potential contributions of these practices towards climate change mitigation and adaptation. Specific crop rotation systems, such as the cereal–legume rotation in temperate regions and the intercropping of maize with beans in tropical environments, are reviewed to provide a comprehensive understanding of their applicability in different agroecological contexts. The review also addresses the challenges related to implementing CRD practices, such as market demand and knowledge transfer, and suggests potential solutions to encourage broader adoption. Lastly, the potential environmental benefits, including carbon sequestration and reduced greenhouse gas emissions, are discussed, highlighting the role of CRD in building resilient agricultural systems. Collectively, this review paper emphasizes the importance of CRD methods as sustainable agricultural practices and provides key insights for researchers and farmers to effectively integrate these practices into farming systems.

Chinese pepper, referring to Zanthoxylum bungeanum Maxim. and Zanthoxylum armatum DC. species, is an important spice crop that has long attracted people’s interest due to its extensive application in Asian cuisine to improve taste. Numerous cultivars have been developed during the long history of domestication and cultivation. However, little to no information is available on the genetic diversity and evolutionary relationships of Chinese pepper cultivars and their historical diversification has not been clarified. Herein, we sequenced two nrDNA non-coding region markers, the external transcribed spacer (ETS) and the internal transcribed spacer 2 (ITS2), to assess genetic diversity and phylogenetic relationships among 39 cultivated and wild populations of Chinese pepper from eight provinces and to address the question of ancient demographic trends which were probably influenced by changing climate during evolutionary history. In total, 31 haplotypes were identified based on 101 polymorphism sites. Our results revealed relatively high level of genetic variation despite long-term cultivation of this crop. AMOVA revealed that genetic variation existed predominantly within provinces rather than among provinces. The genetic structure result based on haplotype network analysis largely reflected historical records, which suggested a Gansu origin for Chinese pepper and an ancient west-to-east spread of Chinese pepper circulating in China. We also provided evidence that changing Pleistocene climates had shaped the demographic trends of Chinese pepper. Taken together, our findings not only suggest that Chinese pepper is a dynamic genetic system that responds to evolutionary forces, but it also provides a fundamental genetic profile for the conservation and responsible exploitation of the extant germplasm of Chinese pepper and for improving the genetic basis for breeding the cultivars.

Purpose Rhizobia play an important ecological and agricultural role in the N₂ cycle between atmosphere and biosphere on the earth. The taxonomy of rhizobia is in a state of flux due to discovery of many novel species, which has led to numbers of revisions in the species description. Results A Gram-stain-negative mobile strain, designated as a22-2^T, was isolated from a nodule of Hedysarum multijugum grown in Northwest China. Phylogenetic analysis of 16S rRNA gene sequence, recA, glnA and atpD showed that the strain was closely related to genus Rhizobium with sequence similarities less than 98.4% (16S rRNA), 85.3% (recA), 90.9% (glnA) and 54.2% (atpD). The strain a22-2^T could grow at temperatures between 20-40°C (optimum, 28°C) and at pH between 5.0-10.0 (optimum, pH 7.0). The cells contained ubiquinone Q-10 as the sole respiratory quinone and had 18:1 ω7c (43.8%) as the major cellular fatty acid. The DNA relatedness with the most closely related reference strains was below 48%. Based on the phenotypic, chemotaxonomic and phylogenetic properties, the strain a22-2^T represents a novel species of the genus Rhizobium, for which the name Rhizobium zhangyense sp. nov. is proposed. The type strain of Rhizobium zhangyense sp. nov. is a22-2^T (= CGMCC 1.15517^T = NBRC 112336^T). The genome sequence of the isolate was determined. It’s G+C content was 61.74%, and the 85% average nucleotide identity of the type strain genome to its best neighbour with a completely sequenced genome (Rhizobium selenitireducens ATCC BAA-1503) indicated low genomic relatedness.