| A facile approach to remediate the microenvironment of saline-alkali soil(SS) was developed using a novel fertilizer named saline-alkali soil remediating fertilizer(SSRF). SSRF was obtained by adding a nanocomposite as the saline-alkali soil remediating agent(SSRA) made up of attapulgite(ATP), phosphogypsum(PG), sodium polyacrylate(SP) and weathered coal(WC) to a traditional fertilizer(TF). SSRF could self-assemble to form 3D micro/nano networks and thus displayed high retaining capacity on water and fertilizer nutrients. In addition, SSRF could effectively reduce the salinity and alkalinity in SS through ion exchange, deactivation and p H adjusting. Thus SSRF could significantly improve the microenvironment of SS, which could facilitate the growth of crops and increase the saline-alkaline tolerance of crops.1. The optimal ratio for SSRA was WATP:WPG:WSP:WWC= 60:30:1:12 through batch tests.2. The microstructure and basic chemical composition of SSRF was analyzed by SEM, FT-IR and XRD. SSRF could self-assemble to form 3D micro/nano networks and work through ion exchange, deactivation and p H adjusting. The synthesis of SSRA and SSRF was a physical process.3. The remediation performance of SSRA was investigated in SI and IE experiment systems. The LSR(%) was 30.54% by SI system and 61.91% by IE system after using SSRA; The p H of SS almost reduced from alkaline to neutral level.4. From the Leaching experiment and MS experiment, SSRA could efficiently control the loss and the MS loss amounts of fertilizer nutrients through leaching, runoff and volatilization. The optimal WU/WSSRA for SSRU was 9:1, while the LLCR(%) was 49.90% and the MLCR(%) was 44.3% in sand, the LLCR(%) was 43.78% and the MLCR(%) was 22.49% in SS. the optimal WN/WSSRA for SSRN was 9:1.2, while the LLCR(%) was 47.23% and the MLCR(%) was 61.71% in sand, the LLCR(%) was 49.02% and the MLCR(%) was 7.02% in SS.5. The corn seeding grows better when the optimal SSRA amount of 0.6 g in 20 g soil through pot experiment. Compared with TF, SSRA could be used as an effective remediation agent for SS to facilitate the growth of the root and height of corn at seedling stage.6. From pot experiment, SSRF could facilitate the growth of corn at seedling stage, and the leaf color was more green, while the corncob was fuller and corn yield was higher at mature period compared with TF. The same amount of fertilizer test in Yinchuan city showed that the germination rate, corncob length, corncob diameter, height, stem diameter and yield of corn increased 19.3%, 12.4%, 14.2%, 12.9%, 23.6%, and 27.0%, respectively. The reducing fertilizer amount by 10% test in Yinchuan city showed that the germination rate, corncob length, corncob diameter, height, stem diameter and yield of corn increased 18.1%, 11.8%, 8.8%, 16.5%, 14.1% and 21.8%, respectively. The same amount of fertilizer test in Shizuishan city showed that the germination rate, corncob length, corncob diameter, height, stem diameter and yield of corn increased 23.9%, 17.3%, 15.2%, 12.1%, 16.4% and 24.0%, respectively. |
