磁化咸水灌溉对土壤团聚体稳定性及其养分影响 postprint

Abstract: In this study, the effects of magnetized saline water irrigation on soil aggregate stability,nutrient distribution, and enrichment were investigated, and the optimal magnetization parameters were clarified. Methods: A field microplot experiment was conducted with four magnetic field intensities (0 T, 0.2 T, 0.4 T, and 0.6 T) and two salinity levels (3 g·L-1, brackish water; 6 g·L-1 , saline water). The characteristics and regulatory effects of different magnetized saline water treatments on soil aggregate size distribution, stability (MWD, GMD), and aggregate available nutrient (N, P, K) contents were examined. Principal component analysis was used to comprehensively evaluate the experimental results and determine the optimal magnetization level. Results: The results demonstrated that (1) magnetic treatment promoted soil aggregation and alleviated salt stress-induced aggregate structure degradation. Compared with nonmagnetized treatments, the proportion of water-stable aggregates >0.25 mm, MWD, and GMD increased significantly under magnetic treatment (P<0.05). (2) Magnetization significantly enhanced the ammonium nitrogen, available phosphorus, and available potassium contents in all aggregate sizes. Furthermore, nutrients were primarily enriched in >0.25 mm macroaggregates (approximately 68% by mass). (3) As the magnetic field intensity increased, the aggregate stability and nutrient content first increased and then decreased, with the peak value appearing at the 0.4 T treatment. Conclusion: Comprehensive analysis indicates that under the present experimental conditions, 0.4 T magnetic treatment yields the best overall improvement in aggregate stability and nutrient enrichment. Therefore, it is recommended as the optimal parameter for improving soil structure and maintaining nutrients under brackish or saline water irrigation.