摘要
低品位磷矿开发应用困难的关键问题在于其活化释放困难以及磷素在土壤中易被固定.将不同添加量的天然腐殖质材料及其衍生物作为促释材料,采用连续水浸提法、X-射线衍射以及红外光谱分析了促释材料对低品位磷矿粉的水溶性磷释放特性以及磷矿粉的结构与成键变化的影响,并通过盆栽试验进一步验证磷矿粉与促释材料在最优配比下的生物肥效.结果表明:随着促释材料添加量的提高,水溶性磷的释放也呈现增加趋势,当天然腐殖质材料和HNO3处理天然腐殖质材料分别与低品位磷矿粉混合的质量比为20:80时,5次水溶性磷释放总量分别为对照处理的1.54倍和1.72倍.X-射线衍射分析结果表明,天然腐殖质材料或HNO3处理天然腐殖质材料混合低品位磷矿粉经过5次浸提后,P2O5和Ca(PO3)2对应的特征衍射峰出现显著下降.红外光谱分析结果表明,天然腐殖质材料或HNO3处理天然腐殖质材料混合低品位磷矿粉经过5次浸提后,可明显看到位于966 cm-1处PO43-对称伸缩振动v1吸收峰消失,同时位于1 127、673和612 cm-1处PO43-非对称伸缩振动v3吸收峰、H2PO4相关吸收峰和HPO42-相关吸收峰强度均显著下降.盆栽试验进一步表明,天然腐殖质材料或HNO3处理天然腐殖质材料作为一种优质有机物料按照6 g·kg-1或9 g·kg-1的施用量同时与低品位磷矿粉按照20∶80的质量比混合后可显著提升土壤的有效磷含量,同时可快速提升土壤有机质含量.天然腐殖质材料按9 g·kg-1的施用量同时与低品位磷矿粉按20∶80的质量比混合,在播种后第14、30、60天土壤有效磷分别较对照处理增加了 29.86％、29.47％、36.48％,土壤有机质分别较CK增加34.16％、8.05％、47.40％.HNO3处理天然腐殖质材料按9 g·kg-1的施用量同时与低品位磷矿粉按20∶80的质量比混合,在播种后第14、30、60天土壤有效磷分别较CK增加了 36.97％、94.44％、34.51％,土壤有机质分别较CK增加27.29％、14.57％、45.41％.天然腐殖质材料或HNO3处理天然腐殖质材料呈酸性、高比表面积、腐殖质含量高、活性官能团数量多等特性是提升低品位磷矿粉的水溶性磷和土壤有效磷含量的主要原因.
Abstract
[Objective]The objective of this study was to disclose the structural characteristics and the relationship with phosphorus validity in the promoted phosphate rocks(PPR),which were made by mixing low-grade phosphate rock powder and natural humic material materials.[Method]Continuous water extraction,X-ray diffraction(XRD),fourier transform infrared spectrometry(FTIR),and pot experiment were carried out to explore the phosphorus validity mechanism of PPR from dynamic release,structural characteristics and fertilizer effects.[Result]The results showed that the release of water-soluble phosphorus showed an increasing trend with the increase of activator addition.After five leachings,the total water-soluble phosphorus released was 1.54 and 1.72 times higher than that of the control treatment when the mass ratio of natural humic material or HNO3-treated natural humic material mixed with low-grade phosphate rock powder was 20∶80.X-ray diffraction analysis showed that the characteristic diffraction peaks corresponding to P2O5 and Ca(PO3)2 showed a significant decrease after five leaching of natural humic material or HNO3-treated natural humic material mixed with low-grade phosphate rock powder.The results of FTIR spectral analysis showed that the disappearance of the PO43-symmetric stretching vibration v1 at 966 cm-1 was evident after five leaching cycles of natural humic material or HNO3-treated natural humic material mixed with low-grade phosphate rock powder,while the intensity of the PO43-asymmetric stretching vibration v3,H2PO4-associated absorption peaks,and HPO42-associated absorption peaks at 1 127,673 and 612 cm-1 were significantly decreased.The pot experiment further showed that natural humic material or HNO3-treated natural humic material as a high-quality organic material applied at 6 g·kg-1 or 9 g·kg-1 while mixed with low-grade phosphate powder at a 20∶80 mass ratio could significantly increase the available phosphorus content of the soil,while rapidly increasing the soil organic matter content.When natural humic material was applied at 9 g·kg-1 and mixed with low-grade phosphate powder at a mass ratio of 20∶80,soil available phosphorus was increased by 29.86％,29.47％,and 36.48％while soil organic matter was increased by 34.16％,8.05％,and 47.40％,respectively,compared to control treatment on days 14,30,and 60 after sowing.Also,when HNO3-treated natural humic material was applied under similar conditions,soil available phosphorus was increased by 36.97％,94.44％,and 34.51％while soil organic matter was increased by 27.29％,14.57％,and 45.41％,respectively,compared with control treatment on days 14,30,and 60 after sowing.[Conclusion]Natural humic material or HNO3-treated natural humic material with acidic pH,high specific surface area,high humus content and a high number of active functional groups were responsible for enhancing the water-soluble phosphorus content of low-grade phosphate rock powder and soil available phosphorus.
基金项目
中国科学院战略性先导科技专项(A类)(XDA28110105)
井冈山农高区省级科技专项"揭榜挂帅"项目(20222-051261)
安徽省水利水电勘测设计研究总院有限公司项目(QTZCFKJS-202302)
维普
万方数据