我国农田磷养分平衡研究进展

从农田养分平衡的角度出发,通过磷平衡的计算方法、我国农田磷平衡的时空变异特征、不同作物农田磷平衡状况、磷平衡对土壤磷含量的影响等4个方面,综述了近年来我国农田磷平衡研究的主要进展。研究表明,我国农田磷平衡表现为整体盈余,且目前盈余程度仍在加剧;但不同区域间变异较大,部分农田磷亏缺,不同区域及不同作物间磷平衡呈现"两极化"发展趋势。不同研究者对于我国农田磷平衡的总盈余量、单位面积盈余量以及空间变异特征所得结果差异较大,不宜直接对比;而对时间变异、不同作物种植类型农田磷平衡以及土壤磷累积规律等方面的研究结果基本一致。为保持土壤磷养分库的稳定与提升,基于我国磷平衡研究现状,探讨了我国未来在磷平衡评价指标、改善磷平衡技术措施方面的几个研究方向,并提出政策措施引导、客观舆论宣传等建议。

Research progress on cropland phosphorus balance in China

Although phosphorus is an essential element for plant growth, over surplus of phosphorus can also cause water environmental hazards such as eutrophication. Phosphorus balance (PB) is an indicator for phosphorus input and output extensively used in agricultural and environmental research. In this paper, PB in croplands in China was reviewed from four different aspects - calculation method, spatio-temporal variability analysis, crop type difference analysis and soil phosphorus content analysis. The study showed surplus PB in China's croplands and with increasing surplus levels. Regional variations in phosphorus surplus were significant, with farmland phosphorus deficiency in some areas which resulted in PB polarization. Due to differences in the calculation parameters or regional planning, vast differences were noted in different reports in terms of amounts of total surplus phosphorus, surplus phosphorus per hectare and spatial variation in surplus phosphorus. Irrespectively, the governing trends in temporal variations, effects of different planting on cropland PB and effects of PB on soil phosphorus content were basically identical. In order to control soil phosphorus polarization and to ensure a stable promotion of soil phosphorus pool in China, it was recommended that future research focused more on areas such as indicator evaluations, technical measurements, policy guides and public opinion propaganda.