[Characteristics of Soil Nutrients and Fungal Community Composition in Crop Rhizosphere Under Different Rotation...

To study the characteristics of soil nutrients and fungal community composition under different rotation patterns in the arid zone of central Ningxia, we used millet rotation soybean (MRG), rotation grain amaranth (MRA), rotation quinoa (MRQ), and continuous millet rotation (CK) as the objects. The soil nutrient content was determined, and the sequence of the ITS variation region of soil fungi was determined using the Illumina MiSeq high-throughput sequencing platform. The results showed that the effects of different rotation patterns on the soil nutrients were different. The soil pH and electrical conductivity decreased under three rotation patterns, and the soil total nitrogen, total potassium, total phosphorus, and organic matter contents increased. The number of OTUs and α diversity index was higher than those of continuous millet rotation. The results of the fungal community composition study showed that Ascomycota was the dominant flora in 4 patterns. The cluster analysis showed that the fungal genus composition of MRA and MRG was the most similar, followed by MRQ, and that of CK was significantly different with the other three rotation patterns. A correlation analysis showed that the soil nutrients were significantly correlated with several dominant fungal genera (P<0.05 or P<0.01). Further, the soil total nitrogen, total potassium, nitrate nitrogen, and organic matter contents were the most important factors influencing the soil fungal communities. Principal component analysis (PCA) showed that the MRG rotation patterns were better than those of the MRA and MRQ patterns. In summary, crop rotation improved the polytrophic index of the fungal community, changed the soil fungal community structure, and improved soil fertility. Among, the millet and soybean rotation were the best, and we have suggested to promote cereal rotation as one of the main rotation patterns in the cereal industry in the central dry zone.