![Sample our Geography journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5937/TOC-Subject-Sample-2021-Geography.jpg"})
ABSTRACT
Long-term, excessive application of synthetic N fertilizers will reduce soil aggregate stability and N supply capacity in corn–wheat (Zea mays L. – Triticum aestivum L.) rotation. This study aimed to determine the effects of soybean (Glycine max L.) on soil aggregation, soil organic N (SON) and net amount of N mineralization (NANM) in wheat season compared with corn. Three rotation systems, corn–wheat (C-W), soybean–wheat (S-W) and soybean inoculated with Rhizobium-wheat (SR-W) were established in 2017. In wet screening, compared with C-W rotation, the mass proportions of large macro-aggregates (LM%) + small macro-aggregates (SM%) at 0–20 cm was increased by 51.9% and 16.6% under S-W and SR-W rotations, respectively, and was increased by 50.6% and 59.8%, respectively, in the 20–40 cm. The proportions of LM + SM-associated N (LMN% + SMN%), ammonium N (AN) and amino acid N (AAN) were higher under the S-W and SR-W rotations. Furthermore, the NANM of S-W and SR-W rotations increased by 34.1% and 28.6% compared with C-W rotation, respectively, and the non-N benefits of soybean played an important role. In conclusion, the improvement degree of soil aggregation by soybean is an important factor affecting soil N mineralization in wheat season.
Acknowledgements
This work was financially supported by the National Natural Science Foundation of China (Grant No. 31902118), and Project Plan of Key Scientific Research in Colleges and Universities of Henan Province (20A210001).
Disclosure statement
No potential conflict of interest was reported by the author(s).